© 2012 Pearson Education, Inc.
PowerPoint®
Lecture Presentations prepared by
Jason LaPres
Lone Star College—North Harris
2...
© 2012 Pearson Education, Inc.
An Introduction to Blood Vessels and
Circulation
• Learning Outcomes
• 21-1 Distinguish amo...
© 2012 Pearson Education, Inc.
An Introduction to Blood Vessels and
Circulation
• Learning Outcomes
• 21-3 Describe the co...
© 2012 Pearson Education, Inc.
An Introduction to Blood Vessels and
Circulation
• Learning Outcomes
• 21-5 Describe the th...
© 2012 Pearson Education, Inc.
An Introduction to Blood Vessels and
Circulation
• Learning Outcomes
• 21-8 Identify the di...
© 2012 Pearson Education, Inc.
An Introduction to Blood Vessels and
Circulation
• Blood Vessels
• Are classified by size a...
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21-1 Classes of Blood Vessels
• Arteries
• Carry blood away from heart
• Arterioles
• Are s...
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21-1 Blood Vessels
• The Largest Blood Vessels
• Attach to heart
• Pulmonary trunk
• Carrie...
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21-1 Blood Vessels
• The Smallest Blood Vessels
• Capillaries
• Have small diameter and thi...
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21-1 Blood Vessels
• The Structure of Vessel Walls
• Walls have three layers
1. Tunica inti...
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21-1 Blood Vessels
• The Tunica Intima (Inner Layer)
• Includes:
• The endothelial lining
•...
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21-1 Blood Vessels
• The Tunica Media (Middle Layer)
• Contains concentric sheets of smooth...
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21-1 Blood Vessels
• The Tunica Externa (Outer Layer)
• Anchors vessel to adjacent tissues ...
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Figure 21-1 Comparisons of a Typical Artery and a Typical Vein
Tunica externa
Tunica media
...
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Figure 21-1 Comparisons of a Typical Artery and a Typical Vein
Lumen
of vein
Lumen
of
arter...
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Table 21-1 Key Terms and Relationships Pertaining to Blood Circulation
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Table 21-1 Key Terms and Relationships Pertaining to Blood Circulation
© 2012 Pearson Education, Inc.
Table 21-1 Key Terms and Relationships Pertaining to Blood Circulation
© 2012 Pearson Education, Inc.
21-1 Blood Vessels
• Differences between Arteries and Veins
• Arteries and veins run side b...
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21-1 Structure and Function of Arteries
• Arteries
• Elasticity allows arteries to absorb p...
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21-1 Structure and Function of Arteries
• Vasoconstriction and Vasodilation
• Affect:
1. Af...
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21-1 Structure and Function of Arteries
• Arteries
• From heart to capillaries, arteries ch...
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21-1 Structure and Function of Arteries
• Elastic Arteries
• Also called conducting arterie...
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21-1 Structure and Function of Arteries
• Muscular Arteries
• Also called distribution arte...
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21-1 Structure and Function of Arteries
• Arterioles
• Are small
• Have little or no tunica...
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21-1 Structure and Function of Arteries
• Artery Diameter
• Small muscular arteries and art...
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21-1 Structure and Function of Arteries
• Aneurysm
• A bulge in an arterial wall
• Is cause...
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Figure 21-2 Histological Structure of Blood Vessels
Large Vein
Medium-Sized Vein
Venule Art...
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Figure 21-2 Histological Structure of Blood Vessels
Large Vein
Medium-Sized Vein
Venule
Tun...
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Figure 21-2 Histological Structure of Blood Vessels
Arteriole
Muscular Artery
Elastic Arter...
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Figure 21-2 Histological Structure of Blood Vessels
Fenestrated Capillary Capillaries Conti...
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Figure 21-3a A Plaque within an Artery
Tunica externa
Lipid deposits
(plaque)
Tunica media
...
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Figure 21-3b A Plaque within an Artery
Plaque deposit
in vessel wall
A section of a coronar...
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21-1 Structure and Function of Capillaries
• Capillaries
• Are smallest vessels with thin w...
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21-1 Structure and Function of Capillaries
• Capillary Structure
• Endothelial tube, inside...
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21-1 Structure and Function of Capillaries
• Continuous Capillaries
• Have complete endothe...
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21-1 Structure and Function of Capillaries
• Specialized Continuous Capillaries
• Are in CN...
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21-1 Structure and Function of Capillaries
• Fenestrated Capillaries
• Have pores in endoth...
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21-1 Structure and Function of Capillaries
• Sinusoids (Sinusoidal Capillaries)
• Have gaps...
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Figure 21-4 Capillary Structure
Basement
membrane
Nucleus
Endothelial cell
Endosomes
Bounda...
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Figure 21-4a Capillary Structure
Basement
membrane
Nucleus
Endothelial cell
Boundary
betwee...
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Figure 21-4b Capillary Structure
Basement
membrane
Nucleus
Endothelial cell
Endosomes
Bound...
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Figure 21-4c Capillary Structure
Gap between
adjacent cells
Sinusoid
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21-1 Structure and Function of Capillaries
• Capillary Beds (Capillary Plexus)
• Connect on...
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Figure 21-5a The Organization of a Capillary Bed
Smooth
muscle cells
Collateral
arteries
Ar...
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Figure 21-5b The Organization of a Capillary Bed
Capillary bed LM × 125
A micrograph of a n...
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21-1 Structure and Function of Capillaries
• Thoroughfare Channels
• Direct capillary conne...
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21-1 Structure and Function of Capillaries
• Collaterals
• Multiple arteries that contribut...
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21-1 Structure and Function of Capillaries
• Angiogenesis
• Formation of new blood vessels
...
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21-1 Structure and Function of Capillaries
• Vasomotion
• Contraction and relaxation cycle ...
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21-1 Structure and Function of Veins
• Veins
• Collect blood from capillaries in tissues an...
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21-1 Structure and Function of Veins
• Venules
• Very small veins
• Collect blood from capi...
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21-1 Structure and Function of Veins
• Large Veins
• Have all three tunica layers
• Thick t...
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Figure 21-6 The Function of Valves in the Venous System
Valve
closed
Valve
closed
Valve ope...
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21-1 Blood Vessels
• The Distribution of Blood
• Heart, arteries, and capillaries
• 30–35% ...
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Figure 21-7 The Distribution of Blood in the Cardiovascular System
Pulm
onary
arteries
3%
L...
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21-1 Blood Vessels
• Capacitance of a Blood Vessel
• The ability to stretch
• Relationship ...
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21-1 Blood Vessels
• Venous Response to Blood Loss
• Vasomotor centers stimulate sympatheti...
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21-2 Pressure and Resistance
• Total Capillary Blood Flow
• Equals cardiac output
• Is dete...
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Figure 21-8 An Overview of Cardiovascular Physiology
Cardiac Output
Venous Return
Regulatio...
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21-2 Pressure and Resistance
• Pressure (P)
• The heart generates P to overcome resistance
...
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21-2 Pressure and Resistance
• Flow (F)
• Is proportional to the pressure difference (∆P)
•...
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21-2 Pressure and Resistance
• Measuring Pressure
1. Blood pressure (BP)
• Arterial pressur...
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21-2 Pressure and Resistance
• Circulatory Pressure
• ∆P across the systemic circuit (about...
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21-2 Pressure and Resistance
• Total Peripheral Resistance
• Vascular resistance
• Blood vi...
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21-2 Pressure and Resistance
• Vascular Resistance
• Due to friction between blood and vess...
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21-2 Pressure and Resistance
• Viscosity
• R caused by molecules and suspended materials
in...
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21-2 Pressure and Resistance
• Turbulence
• Swirling action that disturbs smooth flow of li...
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Figure 21-9 Factors Affecting Friction and Vascular Resistance
Friction and Vessel Length
F...
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Table 21-1 Key Terms and Relationships Pertaining to Blood Circulation
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Table 21-1 Key Terms and Relationships Pertaining to Blood Circulation
© 2012 Pearson Education, Inc.
Table 21-1 Key Terms and Relationships Pertaining to Blood Circulation
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21-2 Pressure and Resistance
• An Overview of Cardiovascular Pressures
• Vessel diameters
•...
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Figure 21-10a Relationships among Vessel Diameter, Cross-Sectional Area, Blood Pressure, an...
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Figure 21-10b Relationships among Vessel Diameter, Cross-Sectional Area, Blood Pressure, an...
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Figure 21-10c Relationships among Vessel Diameter, Cross-Sectional Area, Blood Pressure, an...
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Figure 21-10d Relationships among Vessel Diameter, Cross-Sectional Area, Blood Pressure, an...
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21-2 Pressure and Resistance
• Arterial Blood Pressure
• Systolic pressure
• Peak arterial ...
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21-2 Pressure and Resistance
• Arterial Blood Pressure
• Pulse pressure
• Difference betwee...
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21-2 Pressure and Resistance
• Abnormal Blood Pressure
• Normal = 120/80
• Hypertension
• A...
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21-2 Pressure and Resistance
• Elastic Rebound
• Arterial walls
• Stretch during systole
• ...
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21-2 Pressure and Resistance
• Pressures in Small Arteries and Arterioles
• Pressure and di...
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Figure 21-11 Pressures within the Systemic Circuit
Systolic
Pulse
pressure
Diastolic
mm Hg
...
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21-2 Pressure and Resistance
• Venous Pressure and Venous Return
• Determines the amount of...
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21-2 Pressure and Resistance
• Venous Pressure and Venous Return
• Low venous resistance is...
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21-2 Pressure and Resistance
• Capillary Pressures and Capillary Exchange
• Vital to homeos...
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21-2 Pressure and Resistance
• Diffusion
• Movement of ions or molecules
• From high concen...
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21-2 Pressure and Resistance
• Diffusion Routes
1. Water, ions, and small molecules such as...
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21-2 Pressure and Resistance
• Diffusion Routes
3. Large, water-soluble compounds
• Pass th...
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21-2 Pressure and Resistance
• Filtration
• Driven by hydrostatic pressure
• Water and smal...
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21-2 Pressure and Resistance
• Reabsorption
• The result of osmotic pressure (OP)
• Blood c...
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Figure 21-12 Capillary Filtration
Capillary
hydrostatic
pressure
(CHP) Amino acid
Blood pro...
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21-2 Pressure and Resistance
• Interplay between Filtration and Reabsorption
1. Ensures tha...
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21-2 Pressure and Resistance
• Interplay between Filtration and Reabsorption
3. Assists in ...
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21-2 Pressure and Resistance
• Interplay between Filtration and Reabsorption
• Net hydrosta...
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21-2 Pressure and Resistance
• Factors that Contribute to Net Hydrostatic
Pressure
1. Capil...
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21-2 Pressure and Resistance
• Net Capillary Colloid Osmotic Pressure
• Is the difference b...
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21-2 Pressure and Resistance
• Net Filtration Pressure (NFP)
• The difference between:
• Ne...
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21-2 Pressure and Resistance
• Capillary Exchange
• At arterial end of capillary:
• Fluid m...
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21-2 Pressure and Resistance
• Capillary Exchange
• Transition point between filtration and...
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Figure 21-13 Forces Acting across Capillary Walls
KEY
Arteriole
Filtration
CHP (Capillary
h...
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21-2 Pressure and Resistance
• Capillary Dynamics
• Hemorrhaging
• Reduces CHP and NFP
• In...
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21-3 Cardiovascular Regulation
• Tissue Perfusion
• Blood flow through the tissues
• Carrie...
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21-3 Cardiovascular Regulation
• Cardiovascular Regulation Changes Blood
Flow to a Specific...
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21-3 Cardiovascular Regulation
• Controlling Cardiac Output and Blood Pressure
• Autoregula...
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Figure 21-14 Short-Term and Long-Term Cardiovascular Responses
Autoregulation
Local vasodil...
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Figure 21-14 Short-Term and Long-Term Cardiovascular Responses
Central Regulation
Stimulati...
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21-3 Cardiovascular Regulation
• Autoregulation of Blood Flow within Tissues
• Adjusted by ...
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21-3 Cardiovascular Regulation
• Autoregulation of Blood Flow within Tissues
• Adjusted by ...
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21-3 Cardiovascular Regulation
• Neural Mechanisms
• Cardiovascular (CV) centers of the med...
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21-3 Cardiovascular Regulation
• Vasomotor Center
1. Control of vasoconstriction
• Controll...
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21-3 Cardiovascular Regulation
• Reflex Control of Cardiovascular Function
• Cardiovascular...
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21-3 Cardiovascular Regulation
• Baroreceptor Reflexes
• Stretch receptors in walls of:
1. ...
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21-3 Cardiovascular Regulation
• Baroreceptor Reflexes
• When blood pressure rises, CV cent...
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Figure 21-15 Baroreceptor Reflexes of the Carotid and Aortic Sinuses
Responses to Increased...
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Figure 21-15 Baroreceptor Reflexes of the Carotid and Aortic Sinuses
HOMEOSTASIS
Normal ran...
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21-3 Cardiovascular Regulation
• Chemoreceptor Reflexes
• Peripheral chemoreceptors in caro...
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21-3 Cardiovascular Regulation
• Chemoreceptor Reflexes
• Changes in pH, O2, and CO2 concen...
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Figure 21-16 The Chemoreceptor Reflexes
Increasing CO2 levels,
decreasing pH
and O2 levels
...
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21-3 Cardiovascular Regulation
• CNS Activities and the Cardiovascular
Centers
• Thought pr...
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21-3 Cardiovascular Regulation
• Hormones and Cardiovascular Regulation
• Hormones have sho...
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21-3 Cardiovascular Regulation
• Antidiuretic Hormone (ADH)
• Released by neurohypophysis (...
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21-3 Cardiovascular Regulation
• Angiotensin II
• Responds to fall in renal blood pressure
...
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21-3 Cardiovascular Regulation
• Erythropoietin (EPO)
• Released at kidneys
• Responds to l...
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Figure 21-17a The Hormonal Regulation of Blood Pressure and Blood Volume
HOMEOSTASIS
Factor...
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21-3 Cardiovascular Regulation
• Natriuretic Peptides
• Atrial natriuretic peptide (ANP)
• ...
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Figure 21-17b The Hormonal Regulation of Blood Pressure and Blood Volume
HOMEOSTASIS
Factor...
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21-4 Cardiovascular Adaptation
• Blood, Heart, and Cardiovascular System
• Work together as...
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21-4 Cardiovascular Adaptation
• The Cardiovascular Response to Exercise
• Light Exercise
•...
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21-4 Cardiovascular Adaptation
• The Cardiovascular Response to Exercise
• Heavy Exercise
•...
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Table 21-2 Changes in Blood Distribution during Exercise
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21-4 Cardiovascular Adaptation
• Exercise, Cardiovascular Fitness, and Health
• Regular mod...
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21-4 Cardiovascular Adaptation
Table 21-3 Effects of Training on Cardiovascular Performance...
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21-4 Cardiovascular Adaptation
• The Cardiovascular Response to Hemorrhaging
• Entire cardi...
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21-4 Cardiovascular Adaptation
• Short-Term Elevation of Blood Pressure
• Carotid and aorti...
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21-4 Cardiovascular Adaptation
• Short-Term Elevation of Blood Pressure
• Hormonal effects
...
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21-4 Cardiovascular Adaptation
• Shock
• Short-term responses compensate after blood losses...
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21-4 Cardiovascular Adaptation
• Long-Term Restoration of Blood Volume
• Recall of fluids f...
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Figure 21-18 Cardiovascular Responses to Hemorrhaging and Blood Loss
Normal blood
pressure ...
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21-4 Cardiovascular Adaptation
• Vascular Supply to Special Regions
• Through organs with s...
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21-4 Cardiovascular Adaptation
• Blood Flow to the Brain
• Is top priority
• Brain has high...
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21-4 Cardiovascular Adaptation
• Stroke
• Also called cerebrovascular accident (CVA)
• Bloc...
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21-4 Cardiovascular Adaptation
• Blood Flow to the Heart
• Through coronary arteries
• Oxyg...
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21-4 Cardiovascular Adaptation
• Blood Flow to the Heart
• Epinephrine
• Dilates coronary v...
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21-4 Cardiovascular Adaptation
• Heart Attack
• A blockage of coronary blood flow
• Can cau...
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21-4 Cardiovascular Adaptation
• Blood Flow to the Lungs
• Regulated by O2 levels in alveol...
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21-5 Pulmonary and Systemic Patterns
• Three General Functional Patterns
1. Peripheral arte...
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Figure 21-19 A Schematic Overview of the Pattern of Circulation
Brain
Upper limbs
Lungs
Pul...
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Figure 21-19 A Schematic Overview of the Pattern of Circulation
Brain
Upper limbs
Lungs
Pul...
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21-6 The Pulmonary Circuit
• Deoxygenated Blood Arrives at Heart from
Systemic Circuit
• Pa...
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21-6 The Pulmonary Circuit
• Pulmonary Vessels
• Pulmonary arteries
• Carry deoxygenated bl...
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21-6 The Pulmonary Circuit
• Pulmonary Vessels
• Pulmonary veins
• Carry oxygenated blood
•...
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Figure 21-20 The Pulmonary Circuit
Ascending aorta
Superior vena cava
Right lung
Right pulm...
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Figure 21-20 The Pulmonary Circuit
Aortic arch
Pulmonary trunk
Left lung
Left pulmonary
art...
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21-7 The Systemic Circuit
• The Systemic Circuit
• Contains 84% of blood volume
• Supplies ...
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21-7 The Systemic Circuit
• Systemic Arteries
• Blood moves from left ventricle
• Into asce...
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Figure 21-21 An Overview of the Major Systemic Arteries
Vertebral
Right subclavian
Brachioc...
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Figure 21-21 An Overview of the Major Systemic Arteries
Femoral
Popliteal
Posterior tibial
...
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21-7 The Systemic Circuit
• The Aorta
• The ascending aorta
• Rises from the left ventricle...
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Figure 21-22a Arteries of the Chest and Upper Limb
Suprascapular
Thyrocervical trunk
Right ...
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Figure 21-22b Arteries of the Chest and Upper Limb
Right vertebral Right
common
carotid
Lef...
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21-7 The Systemic Circuit
• Branches of the Aortic Arch
• Deliver blood to head, neck, shou...
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21-7 The Systemic Circuit
• The Subclavian Arteries
• Leaving the thoracic cavity:
• Become...
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Figure 21-22a Arteries of the Chest and Upper Limb
Suprascapular
Thyrocervical trunk
Right ...
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21-7 The Systemic Circuit
• The Brachial Artery
• Divides at coronoid fossa of humerus
• In...
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Figure 21-22a Arteries of the Chest and Upper Limb
Arteries of the chest and upper
limb, a ...
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21-7 The Systemic Circuit
• The Common Carotid Arteries
• Each common carotid divides into:...
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Figure 21-23 Arteries of the Neck and Head
Second rib
Internal thoracic
Axillary
Subclavian...
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Figure 21-23 Arteries of the Neck and Head
Branches of the
External Carotid
Superficial
tem...
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21-7 The Systemic Circuit
• The Vertebral Arteries
• Also supply brain with blood
• Left an...
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21-7 The Systemic Circuit
• Anastomoses
• The cerebral arterial circle (or circle of Willis...
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Figure 21-24a Arteries of the Brain
Anterior
cerebral
Ophthalmic
Internal
carotid (cut)
Mid...
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Figure 21-24b Arteries of the Brain
Middle
cerebral
Anterior
cerebral
Ophthalmic
Cerebral a...
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21-7 The Systemic Circuit
• The Descending Aorta
• Thoracic aorta
• Supplies organs of the ...
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Figure 21-25a Major Arteries of the Trunk
Aortic arch
Internal thoracic
Thoracic aorta
Soma...
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Figure 21-25a Major Arteries of the Trunk
Visceral Branches of
the Thoracic Aorta
Bronchial...
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21-7 The Systemic Circuit
• The Descending Aorta
• Abdominal Aorta
• Divides at terminal se...
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Figure 21-25a Major Arteries of the Trunk
A diagrammatic view, with most of the
thoracic an...
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Figure 21-25a Major Arteries of the Trunk
Celiac Trunk
Left gastric
Splenic
Common hepatic
...
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Figure 21-26 Arteries Supplying the Abdominopelvic Organs
Branches of the
Common Hepatic Ar...
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Figure 21-26 Arteries Supplying the Abdominopelvic Organs
Stomach
The Celiac Trunk
Common h...
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21-7 The Systemic Circuit
• Arteries of the Pelvis and Lower Limbs
• Femoral artery
• Deep ...
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Figure 21-25b Major Arteries of the Trunk
A flowchart showing major arteries of the trunk
L...
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Figure 21-27a Arteries of the Lower Limb
Common
iliac
External
iliac
Superior
gluteal
Ingui...
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Figure 21-27a Arteries of the Lower Limb
Anterior view
Popliteal
Anterior tibial
Posterior
...
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Figure 21-27b Arteries of the Lower Limb
Posterior view
Medial
femoral
circumflex
Femoral
I...
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Figure 21-27b Arteries of the Lower Limb
Posterior view
Popliteal
Anterior tibial
Posterior...
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Figure 21-27c Arteries of the Lower Limb
Deep
femoral
Femoral
Descending
genicular
Poplitea...
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21-7 The Systemic Circuit
• Systemic Veins
• Complementary Arteries and Veins
• Run side by...
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Figure 21-28 An Overview of the Major Systemic Veins
Vertebral
External jugular Internal ju...
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Figure 21-28 An Overview of the Major Systemic Veins
Superficial veins
Deep veins
KEY
Femor...
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21-7 The Systemic Circuit
• The Superior Vena Cava (SVC)
• Receives blood from the tissues ...
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Figure 21-29c Major Veins of the Head, Neck, and Brain
Superior sagittal sinus
Superficial ...
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21-7 The Systemic Circuit
• The Dural Sinuses
• Superficial cerebral veins and small veins ...
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Figure 21-29b Major Veins of the Head, Neck, and Brain
Straight
sinus
Occipital
sinus
Right...
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21-7 The Systemic Circuit
• Cerebral Veins
• Great cerebral vein
• Drains to straight sinus...
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Figure 21-29a Major Veins of the Head, Neck, and Brain
An inferior view of the brain, showi...
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21-7 The Systemic Circuit
• Superficial Veins of the Head and Neck
• Converge to form:
• Te...
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Figure 21-29c Major Veins of the Head, Neck, and Brain
Superior sagittal sinus
Superficial ...
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21-7 The Systemic Circuit
• Veins of the Hand
• Digital veins
• Empty into superficial and ...
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21-7 The Systemic Circuit
• Veins of the Hand
• Superficial arch empties into:
• Cephalic v...
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Figure 21-30 The Venous Drainage of the Abdomen and Chest
Palmar venous
arches
Digital vein...
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21-7 The Systemic Circuit
• The Brachial Vein
• Merges with basilic vein
• To become axilla...
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Figure 21-30 The Venous Drainage of the Abdomen and Chest
Deep veins
Superficial veins
KEY
...
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21-7 The Systemic Circuit
• Veins of the Thoracic Cavity
• Brachiocephalic vein receives bl...
© 2012 Pearson Education, Inc.
21-7 The Systemic Circuit
• Tributaries of the Superior Vena Cava
• Azygos vein and hemiazy...
© 2012 Pearson Education, Inc.
Figure 21-30 The Venous Drainage of the Abdomen and Chest
Medial sacral
Deep veins
Superfic...
© 2012 Pearson Education, Inc.
Figure 21-31a Flowcharts of Circulation to the Superior and Inferior Venae Cavae
Tributarie...
© 2012 Pearson Education, Inc.
Figure 21-31a Flowcharts of Circulation to the Superior and Inferior Venae Cavae
Tributarie...
© 2012 Pearson Education, Inc.
21-7 The Systemic Circuit
• The Inferior Vena Cava (IVC)
• Collects blood from organs infer...
© 2012 Pearson Education, Inc.
21-7 The Systemic Circuit
• Veins of the Foot
• Capillaries of the sole
• Drain into a netw...
© 2012 Pearson Education, Inc.
21-7 The Systemic Circuit
• The Dorsal Venous Arch
• Collects blood from:
• Superior surfac...
© 2012 Pearson Education, Inc.
21-7 The Systemic Circuit
• The Popliteal Vein
• Becomes the femoral vein
• Before entering...
© 2012 Pearson Education, Inc.
21-7 The Systemic Circuit
• The External Iliac Veins
• Are joined by internal iliac veins
•...
© 2012 Pearson Education, Inc.
Figure 21-32a Venous Drainage from the Lower Limb
External iliac
Common iliac
Internal ilia...
© 2012 Pearson Education, Inc.
Figure 21-32b Venous Drainage from the Lower Limb
External iliac
Gluteal
Internal pudendal
...
© 2012 Pearson Education, Inc.
Figure 21-32c Venous Drainage from the Lower Limb
EXTERNAL ILIAC
Small
saphenous
Femoral
Po...
© 2012 Pearson Education, Inc.
21-7 The Systemic Circuit
• Major Tributaries of the Abdominal Inferior Vena
Cava
1. Lumbar...
© 2012 Pearson Education, Inc.
21-7 The Systemic Circuit
• The Hepatic Portal System
• Connects two capillary beds
• Deliv...
© 2012 Pearson Education, Inc.
21-7 The Systemic Circuit
Tributaries of the Hepatic Portal Vein
1. Inferior mesenteric vei...
© 2012 Pearson Education, Inc.
21-7 The Systemic Circuit
• Blood Processed in Liver
• After processing in liver sinusoids ...
© 2012 Pearson Education, Inc.
Figure 21-33 The Hepatic Portal System
Inferior vena cava
Hepatic
Cystic
Hepatic portal
Pan...
© 2012 Pearson Education, Inc.
Figure 21-33 The Hepatic Portal System
Left gastric
Right gastric
Stomach
Spleen
Pancreas
L...
© 2012 Pearson Education, Inc.
Figure 21-31b Flowcharts of Circulation to the Superior and Inferior Venae Cavae
Tributarie...
© 2012 Pearson Education, Inc.
21-8 Fetal and Maternal Circulation
• Fetal and Maternal Cardiovascular Systems
Promote the...
© 2012 Pearson Education, Inc.
21-8 Fetal and Maternal Circulation
• Placental Blood Supply
• Blood flows to the placenta
...
© 2012 Pearson Education, Inc.
21-8 Fetal and Maternal Circulation
• Before Birth
• Fetal lungs are collapsed
• O2 provide...
© 2012 Pearson Education, Inc.
21-8 Fetal and Maternal Circulation
• Fetal Pulmonary Circulation Bypasses
• Foramen ovale
...
© 2012 Pearson Education, Inc.
21-8 Fetal and Maternal Circulation
• Cardiovascular Changes at Birth
• Newborn breathes ai...
© 2012 Pearson Education, Inc.
Figure 21-34a Fetal Circulation
Placenta
Aorta
Foramen ovale (open)
Ductus arteriosus (open...
© 2012 Pearson Education, Inc.
Figure 21-34b Fetal Circulation
Blood flow through the
neonatal (newborn) heart
after deliv...
© 2012 Pearson Education, Inc.
Figure 21-35 Congenital Heart Problems
Normal Heart Structure
Most heart problems reflect
d...
© 2012 Pearson Education, Inc.
21-8 Fetal and Maternal Circulation
• Patent Foramen Ovale and Patent Ductus
Arteriosus
• I...
© 2012 Pearson Education, Inc.
21-8 Fetal and Maternal Circulation
• Patent Foramen Ovale and Patent Ductus
Arteriosus
• P...
© 2012 Pearson Education, Inc.
Figure 21-35 Congenital Heart Problems
Patent Foramen Ovale and Patent Ductus Arteriosus
If...
© 2012 Pearson Education, Inc.
21-8 Fetal and Maternal Circulation
• Tetralogy of Fallot
• Complex group of heart and circ...
© 2012 Pearson Education, Inc.
Figure 21-35 Congenital Heart Problems
Tetralogy of Fallot
ventricle is enlarged and both v...
© 2012 Pearson Education, Inc.
21-8 Fetal and Maternal Circulation
• Ventricular Septal Defect
• Openings in interventricu...
© 2012 Pearson Education, Inc.
Figure 21-35 Congenital Heart Problems
Ventricular Septal Defect
Ventricular septal defects...
© 2012 Pearson Education, Inc.
21-8 Fetal and Maternal Circulation
• Atrioventricular Septal Defect
• Both the atria and v...
© 2012 Pearson Education, Inc.
Figure 21-35 Congenital Heart Problems
In an atriovenricular septal defect, both the atria ...
© 2012 Pearson Education, Inc.
21-8 Fetal and Maternal Circulation
• Transposition of Great Vessels
• The aorta is connect...
© 2012 Pearson Education, Inc.
Figure 21-35 Congenital Heart Problems
In the transposition of great vessels, the
aorta is ...
© 2012 Pearson Education, Inc.
21-9 Effects of Aging and the Cardiovascular
System
• Cardiovascular Capabilities Decline w...
© 2012 Pearson Education, Inc.
21-9 Effects of Aging and the Cardiovascular
System
• Three Age-Related Changes in Blood
1....
© 2012 Pearson Education, Inc.
21-9 Effects of Aging and the Cardiovascular
System
• Five Age-Related Changes in the Heart...
© 2012 Pearson Education, Inc.
21-9 Effects of Aging and the Cardiovascular
System
• Three Age-Related Changes in Blood Ve...
© 2012 Pearson Education, Inc.
21-9 Cardiovascular System Integration
• Many Categories of Cardiovascular Disorders
• Diso...
© 2012 Pearson Education, Inc.
Figure 21-36 System Integrator: The Cardiovascular System
S Y S T E M I N T E G R A T O R
B...
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169 Ch 21_lecture_presentation

  1. 1. © 2012 Pearson Education, Inc. PowerPoint® Lecture Presentations prepared by Jason LaPres Lone Star College—North Harris 21 Blood Vessels and Circulation
  2. 2. © 2012 Pearson Education, Inc. An Introduction to Blood Vessels and Circulation • Learning Outcomes • 21-1 Distinguish among the types of blood vessels based on their structure and function, and describe how and where fluid and dissolved materials enter and leave the cardiovascular system. • 21-2 Explain the mechanisms that regulate blood flow through vessels, describe the factors that influence blood pressure, and discuss the mechanisms that regulate movement of fluids between capillaries and interstitial spaces.
  3. 3. © 2012 Pearson Education, Inc. An Introduction to Blood Vessels and Circulation • Learning Outcomes • 21-3 Describe the control mechanisms that regulate blood flow and pressure in tissues, and explain how the activities of the cardiac, vasomotor, and respiratory centers are coordinated to control blood flow through the tissues. • 21-4 Explain the cardiovascular system’s homeostatic response to exercise and hemorrhaging, and identify the principal blood vessels and functional characteristics of the special circulation to the brain, heart, and lungs.
  4. 4. © 2012 Pearson Education, Inc. An Introduction to Blood Vessels and Circulation • Learning Outcomes • 21-5 Describe the three general functional patterns seen in the pulmonary and systemic circuits of the cardiovascular system. • 21-6 Identify the major arteries and veins of the pulmonary circuit. • 21-7 Identify the major arteries and veins of the systemic circuit.
  5. 5. © 2012 Pearson Education, Inc. An Introduction to Blood Vessels and Circulation • Learning Outcomes • 21-8 Identify the differences between fetal and adult circulation patterns, and describe the changes in the patterns of blood flow that occur at birth. • 21-9 Discuss the effects of aging on the cardiovascular system, and give examples of interactions between the cardiovascular system and other organ systems.
  6. 6. © 2012 Pearson Education, Inc. An Introduction to Blood Vessels and Circulation • Blood Vessels • Are classified by size and histological organization • Are instrumental in overall cardiovascular regulation
  7. 7. © 2012 Pearson Education, Inc. 21-1 Classes of Blood Vessels • Arteries • Carry blood away from heart • Arterioles • Are smallest branches of arteries • Capillaries • Are smallest blood vessels • Location of exchange between blood and interstitial fluid • Venules • Collect blood from capillaries • Veins • Return blood to heart
  8. 8. © 2012 Pearson Education, Inc. 21-1 Blood Vessels • The Largest Blood Vessels • Attach to heart • Pulmonary trunk • Carries blood from right ventricle • To pulmonary circulation • Aorta • Carries blood from left ventricle • To systemic circulation
  9. 9. © 2012 Pearson Education, Inc. 21-1 Blood Vessels • The Smallest Blood Vessels • Capillaries • Have small diameter and thin walls • Chemicals and gases diffuse across walls
  10. 10. © 2012 Pearson Education, Inc. 21-1 Blood Vessels • The Structure of Vessel Walls • Walls have three layers 1. Tunica intima 2. Tunica media 3. Tunica externa
  11. 11. © 2012 Pearson Education, Inc. 21-1 Blood Vessels • The Tunica Intima (Inner Layer) • Includes: • The endothelial lining • Connective tissue layer • Internal elastic membrane • In arteries, is a layer of elastic fibers in outer margin of tunica intima
  12. 12. © 2012 Pearson Education, Inc. 21-1 Blood Vessels • The Tunica Media (Middle Layer) • Contains concentric sheets of smooth muscle in loose connective tissue • Binds to inner and outer layers • External elastic membrane of the tunica media • Separates tunica media from tunica externa
  13. 13. © 2012 Pearson Education, Inc. 21-1 Blood Vessels • The Tunica Externa (Outer Layer) • Anchors vessel to adjacent tissues in arteries • Contains collagen fibers • Elastic fibers • In veins • Contains elastic fibers • Smooth muscle cells • Vasa vasorum (“vessels of vessels”) • Small arteries and veins • In walls of large arteries and veins • Supply cells of tunica media and tunica externa
  14. 14. © 2012 Pearson Education, Inc. Figure 21-1 Comparisons of a Typical Artery and a Typical Vein Tunica externa Tunica media Tunica intima Smooth muscle Internal elastic membrane External elastic membrane Endothelium ARTERY Elastic fiber Lumen of vein Lumen of artery Artery and vein LM × 60
  15. 15. © 2012 Pearson Education, Inc. Figure 21-1 Comparisons of a Typical Artery and a Typical Vein Lumen of vein Lumen of artery Artery and vein LM × 60 Tunica media Tunica intima Smooth muscle Endothelium Tunica externa VEIN
  16. 16. © 2012 Pearson Education, Inc. Table 21-1 Key Terms and Relationships Pertaining to Blood Circulation
  17. 17. © 2012 Pearson Education, Inc. Table 21-1 Key Terms and Relationships Pertaining to Blood Circulation
  18. 18. © 2012 Pearson Education, Inc. Table 21-1 Key Terms and Relationships Pertaining to Blood Circulation
  19. 19. © 2012 Pearson Education, Inc. 21-1 Blood Vessels • Differences between Arteries and Veins • Arteries and veins run side by side • Arteries have thicker walls and higher blood pressure • Collapsed artery has small, round lumen (internal space) • Vein has a large, flat lumen • Vein lining contracts, artery lining does not • Artery lining folds • Arteries more elastic • Veins have valves
  20. 20. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Arteries • Arteries • Elasticity allows arteries to absorb pressure waves that come with each heartbeat • Contractility • Arteries change diameter • Controlled by sympathetic division of ANS • Vasoconstriction • The contraction of arterial smooth muscle by the ANS • Vasodilation • The relaxation of arterial smooth muscle • Enlarging the lumen
  21. 21. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Arteries • Vasoconstriction and Vasodilation • Affect: 1. Afterload on heart 2. Peripheral blood pressure 3. Capillary blood flow
  22. 22. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Arteries • Arteries • From heart to capillaries, arteries change • From elastic arteries • To muscular arteries • To arterioles
  23. 23. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Arteries • Elastic Arteries • Also called conducting arteries • Large vessels (e.g., pulmonary trunk and aorta) • Tunica media has many elastic fibers and few muscle cells • Elasticity evens out pulse force
  24. 24. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Arteries • Muscular Arteries • Also called distribution arteries • Are medium sized (most arteries) • Tunica media has many muscle cells
  25. 25. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Arteries • Arterioles • Are small • Have little or no tunica externa • Have thin or incomplete tunica media
  26. 26. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Arteries • Artery Diameter • Small muscular arteries and arterioles • Change with sympathetic or endocrine stimulation • Constricted arteries oppose blood flow • Resistance (R) • Resistance vessels - arterioles
  27. 27. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Arteries • Aneurysm • A bulge in an arterial wall • Is caused by weak spot in elastic fibers • Pressure may rupture vessel
  28. 28. © 2012 Pearson Education, Inc. Figure 21-2 Histological Structure of Blood Vessels Large Vein Medium-Sized Vein Venule Arteriole Muscular Artery Elastic Artery Fenestrated Capillary Capillaries Continuous Capillary Pores Endothelial cells Basement membrane Basement membrane Endothelial cells Tunica externa Endothelium Tunica externa Tunica media Endothelium Tunica intima Tunica externa Tunica media Endothelium Tunica intima Internal elastic layer Endothelium Tunica intima Tunica media Tunica externa Tunica externa Tunica media Endothelium Tunica intima Smooth muscle cells (Media) Endothelium Basement membrane
  29. 29. © 2012 Pearson Education, Inc. Figure 21-2 Histological Structure of Blood Vessels Large Vein Medium-Sized Vein Venule Tunica externa Endothelium Tunica externa Tunica media Endothelium Tunica intima Tunica externa Tunica media Endothelium Tunica intima
  30. 30. © 2012 Pearson Education, Inc. Figure 21-2 Histological Structure of Blood Vessels Arteriole Muscular Artery Elastic Artery Internal elastic layer Endothelium Tunica intima Tunica media Tunica externa Tunica externa Tunica media Endothelium Tunica intima Smooth muscle cells (Media) Endothelium Basement membrane
  31. 31. © 2012 Pearson Education, Inc. Figure 21-2 Histological Structure of Blood Vessels Fenestrated Capillary Capillaries Continuous Capillary Pores Endothelial cells Basement membrane Basement membrane Endothelial cells
  32. 32. © 2012 Pearson Education, Inc. Figure 21-3a A Plaque within an Artery Tunica externa Lipid deposits (plaque) Tunica media Coronary artery A cross-sectional view of a large plaque LM × 6
  33. 33. © 2012 Pearson Education, Inc. Figure 21-3b A Plaque within an Artery Plaque deposit in vessel wall A section of a coronary artery narrowed by plaque formation
  34. 34. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Capillaries • Capillaries • Are smallest vessels with thin walls • Microscopic capillary networks permeate all active tissues • Capillary function • Location of all exchange functions of cardiovascular system • Materials diffuse between blood and interstitial fluid
  35. 35. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Capillaries • Capillary Structure • Endothelial tube, inside thin basement membrane • No tunica media • No tunica externa • Diameter is similar to red blood cell
  36. 36. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Capillaries • Continuous Capillaries • Have complete endothelial lining • Are found in all tissues except epithelia and cartilage • Functions of continuous capillaries • Permit diffusion of water, small solutes, and lipid- soluble materials • Block blood cells and plasma proteins
  37. 37. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Capillaries • Specialized Continuous Capillaries • Are in CNS and thymus • Have very restricted permeability • For example, the blood–brain barrier
  38. 38. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Capillaries • Fenestrated Capillaries • Have pores in endothelial lining • Permit rapid exchange of water and larger solutes between plasma and interstitial fluid • Are found in: • Choroid plexus • Endocrine organs • Kidneys • Intestinal tract
  39. 39. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Capillaries • Sinusoids (Sinusoidal Capillaries) • Have gaps between adjacent endothelial cells • Liver • Spleen • Bone marrow • Endocrine organs • Permit free exchange • Of water and large plasma proteins • Between blood and interstitial fluid • Phagocytic cells monitor blood at sinusoids
  40. 40. © 2012 Pearson Education, Inc. Figure 21-4 Capillary Structure Basement membrane Nucleus Endothelial cell Endosomes Boundary between endothelial cells Fenestrations, or pores Boundary between endothelial cells Basement membrane Endosomes Basement membrane Gap between adjacent cells SinusoidFenestrated capillaryContinuous capillary
  41. 41. © 2012 Pearson Education, Inc. Figure 21-4a Capillary Structure Basement membrane Nucleus Endothelial cell Boundary between endothelial cells Endosomes Basement membrane Continuous capillary
  42. 42. © 2012 Pearson Education, Inc. Figure 21-4b Capillary Structure Basement membrane Nucleus Endothelial cell Endosomes Boundary between endothelial cells Fenestrations, or pores Basement membrane Fenestrated capillary
  43. 43. © 2012 Pearson Education, Inc. Figure 21-4c Capillary Structure Gap between adjacent cells Sinusoid
  44. 44. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Capillaries • Capillary Beds (Capillary Plexus) • Connect one arteriole and one venule • Precapillary Sphincter • Guards entrance to each capillary • Opens and closes, causing capillary blood to flow in pulses
  45. 45. © 2012 Pearson Education, Inc. Figure 21-5a The Organization of a Capillary Bed Smooth muscle cells Collateral arteries Arteriole Metarterioles Thoroughfare channel Vein Venule Capillaries Section of precapillary sphincter Precapillary sphincters Arteriovenous anastomosis A typical capillary bed. Solid arrows indicate consistant blood flow; dashed arrows indicate variable or pulsating blood flow. Small venule KEY Consistent blood flow Variable blood flow
  46. 46. © 2012 Pearson Education, Inc. Figure 21-5b The Organization of a Capillary Bed Capillary bed LM × 125 A micrograph of a number of capillary beds. Capillary beds Metarterioles Arteriole Small artery
  47. 47. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Capillaries • Thoroughfare Channels • Direct capillary connections between arterioles and venules • Controlled by smooth muscle segments (metarterioles)
  48. 48. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Capillaries • Collaterals • Multiple arteries that contribute to one capillary bed • Allow circulation if one artery is blocked • Arterial anastomosis • Fusion of two collateral arteries • Arteriovenous anastomoses • Direct connections between arterioles and venules • Bypass the capillary bed
  49. 49. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Capillaries • Angiogenesis • Formation of new blood vessels • Vascular endothelial growth factor (VEGF) • Occurs in the embryo as tissues and organs develop • Occurs in response to factors released by cells that are hypoxic, or oxygen-starved • Most important in cardiac muscle, where it takes place in response to a chronically constricted or occluded vessel
  50. 50. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Capillaries • Vasomotion • Contraction and relaxation cycle of capillary sphincters • Causes blood flow in capillary beds to constantly change routes
  51. 51. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Veins • Veins • Collect blood from capillaries in tissues and organs • Return blood to heart • Are larger in diameter than arteries • Have thinner walls than arteries • Have lower blood pressure
  52. 52. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Veins • Venules • Very small veins • Collect blood from capillaries • Medium-sized veins • Thin tunica media and few smooth muscle cells • Tunica externa with longitudinal bundles of elastic fibers
  53. 53. © 2012 Pearson Education, Inc. 21-1 Structure and Function of Veins • Large Veins • Have all three tunica layers • Thick tunica externa • Thin tunica media • Venous Valves • Folds of tunica intima • Prevent blood from flowing backward • Compression pushes blood toward heart
  54. 54. © 2012 Pearson Education, Inc. Figure 21-6 The Function of Valves in the Venous System Valve closed Valve closed Valve opens above contracting muscle Valve closes below contracting muscle
  55. 55. © 2012 Pearson Education, Inc. 21-1 Blood Vessels • The Distribution of Blood • Heart, arteries, and capillaries • 30–35% of blood volume • Venous system • 60–65% • 1/3 of venous blood is in the large venous networks of the liver, bone marrow, and skin
  56. 56. © 2012 Pearson Education, Inc. Figure 21-7 The Distribution of Blood in the Cardiovascular System Pulm onary arteries 3% Large venous networks (liver, bone marrow, skin) 21% Venules and medium-sized veins 25% Pulm onary circuit9% Heart7% System ic Pulm onary capillaries 2% Pulmonary veins 4% Heart 7% Aorta 2%Elastic arteries 4% Systemiccapillaries7% Muscular arteries 5% Arterioles 2% Large veins 18% Systemic capillaries 7% arterialsystem13% Systemicvenoussystem64%
  57. 57. © 2012 Pearson Education, Inc. 21-1 Blood Vessels • Capacitance of a Blood Vessel • The ability to stretch • Relationship between blood volume and blood pressure • Veins (capacitance vessels) stretch more than arteries
  58. 58. © 2012 Pearson Education, Inc. 21-1 Blood Vessels • Venous Response to Blood Loss • Vasomotor centers stimulate sympathetic nerves 1. Systemic veins constrict (venoconstriction) 2. Veins in liver, skin, and lungs redistribute venous reserve
  59. 59. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Total Capillary Blood Flow • Equals cardiac output • Is determined by: • Pressure (P) and resistance (R) in the cardiovascular system
  60. 60. © 2012 Pearson Education, Inc. Figure 21-8 An Overview of Cardiovascular Physiology Cardiac Output Venous Return Regulation (Neural and Hormonal) Venous Pressure Arterial Blood Pressure Peripheral Resistance Capillary Pressure Capillary exchange Interstitial fluid
  61. 61. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Pressure (P) • The heart generates P to overcome resistance • Absolute pressure is less important than pressure gradient • The Pressure Gradient (∆P) • Circulatory pressure • The difference between: • Pressure at the heart • And pressure at peripheral capillary beds
  62. 62. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Flow (F) • Is proportional to the pressure difference (∆P) • Divided by R
  63. 63. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Measuring Pressure 1. Blood pressure (BP) • Arterial pressure (mm Hg) 2. Capillary hydrostatic pressure (CHP) • Pressure within the capillary beds 3. Venous pressure • Pressure in the venous system
  64. 64. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Circulatory Pressure • ∆P across the systemic circuit (about 100 mm Hg) • Circulatory pressure must overcome total peripheral resistance • R of entire cardiovascular system
  65. 65. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Total Peripheral Resistance • Vascular resistance • Blood viscosity • Turbulence
  66. 66. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Vascular Resistance • Due to friction between blood and vessel walls • Depends on vessel length and vessel diameter • Adult vessel length is constant • Vessel diameter varies by vasodilation and vasoconstriction • R increases exponentially as vessel diameter decreases
  67. 67. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Viscosity • R caused by molecules and suspended materials in a liquid • Whole blood viscosity is about four times that of water
  68. 68. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Turbulence • Swirling action that disturbs smooth flow of liquid • Occurs in heart chambers and great vessels • Atherosclerotic plaques cause abnormal turbulence
  69. 69. © 2012 Pearson Education, Inc. Figure 21-9 Factors Affecting Friction and Vascular Resistance Friction and Vessel Length Friction and Vessel Diameter Vessel Length versus Vessel Diameter Factors Affecting Vascular Resistance Internal surface area = 1 Internal surface area = 2 Resistance to flow = 1 Flow = 1 Resistance to flow = 2 Flow = 2 1/ Greatest resistance, slowest flow near surfaces Least resistance, greatest flow at center Diameter = 2 cm Diameter = 1 cm Resistance to flow = 1 Resistance to flow = 16 Plaque deposit Turbulence Turbulence
  70. 70. © 2012 Pearson Education, Inc. Table 21-1 Key Terms and Relationships Pertaining to Blood Circulation
  71. 71. © 2012 Pearson Education, Inc. Table 21-1 Key Terms and Relationships Pertaining to Blood Circulation
  72. 72. © 2012 Pearson Education, Inc. Table 21-1 Key Terms and Relationships Pertaining to Blood Circulation
  73. 73. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • An Overview of Cardiovascular Pressures • Vessel diameters • Total cross-sectional areas • Pressures • Velocity of blood flow
  74. 74. © 2012 Pearson Education, Inc. Figure 21-10a Relationships among Vessel Diameter, Cross-Sectional Area, Blood Pressure, and Blood Velocity within the Systemic Circuit Vessel diameter (cm) Vessel diameter
  75. 75. © 2012 Pearson Education, Inc. Figure 21-10b Relationships among Vessel Diameter, Cross-Sectional Area, Blood Pressure, and Blood Velocity within the Systemic Circuit Total cross-sectional area of vessels Cross- sectional area (cm2 )
  76. 76. © 2012 Pearson Education, Inc. Figure 21-10c Relationships among Vessel Diameter, Cross-Sectional Area, Blood Pressure, and Blood Velocity within the Systemic Circuit Average blood pressure Average blood pressure (mm Hg)
  77. 77. © 2012 Pearson Education, Inc. Figure 21-10d Relationships among Vessel Diameter, Cross-Sectional Area, Blood Pressure, and Blood Velocity within the Systemic Circuit Velocity of blood flow Velocity of blood flow (cm/sec)
  78. 78. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Arterial Blood Pressure • Systolic pressure • Peak arterial pressure during ventricular systole • Diastolic pressure • Minimum arterial pressure during diastole
  79. 79. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Arterial Blood Pressure • Pulse pressure • Difference between systolic pressure and diastolic pressure • Mean arterial pressure (MAP) • MAP = diastolic pressure + 1/3 pulse pressure
  80. 80. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Abnormal Blood Pressure • Normal = 120/80 • Hypertension • Abnormally high blood pressure • Greater than 140/90 • Hypotension • Abnormally low blood pressure
  81. 81. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Elastic Rebound • Arterial walls • Stretch during systole • Rebound (recoil to original shape) during diastole • Keep blood moving during diastole
  82. 82. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Pressures in Small Arteries and Arterioles • Pressure and distance • MAP and pulse pressure decrease with distance from heart • Blood pressure decreases with friction • Pulse pressure decreases due to elastic rebound
  83. 83. © 2012 Pearson Education, Inc. Figure 21-11 Pressures within the Systemic Circuit Systolic Pulse pressure Diastolic mm Hg Mean arterial pressure
  84. 84. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Venous Pressure and Venous Return • Determines the amount of blood arriving at right atrium each minute • Low effective pressure in venous system
  85. 85. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Venous Pressure and Venous Return • Low venous resistance is assisted by: • Muscular compression of peripheral veins • Compression of skeletal muscles pushes blood toward heart (one-way valves) • The respiratory pump • Thoracic cavity action • Inhaling decreases thoracic pressure • Exhaling raises thoracic pressure
  86. 86. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Capillary Pressures and Capillary Exchange • Vital to homeostasis • Moves materials across capillary walls by: • Diffusion • Filtration • Reabsorption
  87. 87. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Diffusion • Movement of ions or molecules • From high concentration • To lower concentration • Along the concentration gradient
  88. 88. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Diffusion Routes 1. Water, ions, and small molecules such as glucose • Diffuse between adjacent endothelial cells • Or through fenestrated capillaries 2. Some ions (Na+ , K+ , Ca2+ , Cl− ) • Diffuse through channels in plasma membranes
  89. 89. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Diffusion Routes 3. Large, water-soluble compounds • Pass through fenestrated capillaries 3. Lipids and lipid-soluble materials such as O2 and CO2 • Diffuse through endothelial plasma membranes 3. Plasma proteins • Cross endothelial lining in sinusoids
  90. 90. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Filtration • Driven by hydrostatic pressure • Water and small solutes forced through capillary wall • Leaves larger solutes in bloodstream
  91. 91. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Reabsorption • The result of osmotic pressure (OP) • Blood colloid osmotic pressure (BCOP) • Equals pressure required to prevent osmosis • Caused by suspended blood proteins that are too large to cross capillary walls
  92. 92. © 2012 Pearson Education, Inc. Figure 21-12 Capillary Filtration Capillary hydrostatic pressure (CHP) Amino acid Blood protein Glucose Ions Interstitial fluid Hydrogen bond Water molecule Small solutes Endothelial cell 2 Endothelial cell 1
  93. 93. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Interplay between Filtration and Reabsorption 1. Ensures that plasma and interstitial fluid are in constant communication and mutual exchange 2. Accelerates distribution of: • Nutrients, hormones, and dissolved gases throughout tissues
  94. 94. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Interplay between Filtration and Reabsorption 3. Assists in the transport of: • Insoluble lipids and tissue proteins that cannot enter bloodstream by crossing capillary walls 4. Has a flushing action that carries bacterial toxins and other chemical stimuli to: • Lymphatic tissues and organs responsible for providing immunity to disease
  95. 95. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Interplay between Filtration and Reabsorption • Net hydrostatic pressure • Forces water out of solution • Net osmotic pressure • Forces water into solution • Both control filtration and reabsorption through capillaries
  96. 96. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Factors that Contribute to Net Hydrostatic Pressure 1. Capillary hydrostatic pressure (CHP) 2. Interstitial fluid hydrostatic pressure (IHP) • Net capillary hydrostatic pressure tends to push water and solutes: • Out of capillaries • Into interstitial fluid
  97. 97. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Net Capillary Colloid Osmotic Pressure • Is the difference between: 1. Blood colloid osmotic pressure (BCOP) 2. Interstitial fluid colloid osmotic pressure (ICOP) • Pulls water and solutes: • Into a capillary • From interstitial fluid
  98. 98. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Net Filtration Pressure (NFP) • The difference between: • Net hydrostatic pressure • Net osmotic pressure NFP = (CHP – IHP) – (BCOP – ICOP)
  99. 99. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Capillary Exchange • At arterial end of capillary: • Fluid moves out of capillary • Into interstitial fluid • At venous end of capillary: • Fluid moves into capillary • Out of interstitial fluid
  100. 100. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Capillary Exchange • Transition point between filtration and reabsorption • Is closer to venous end than arterial end • Capillaries filter more than they reabsorb • Excess fluid enters lymphatic vessels
  101. 101. © 2012 Pearson Education, Inc. Figure 21-13 Forces Acting across Capillary Walls KEY Arteriole Filtration CHP (Capillary hydrostatic pressure) Venule BCOP (Blood colloid osmotic pressure) NFP (Net filtration pressure) 24 L/day 20.4 L/day No net fluid movement Reabsorption 35 mm Hg 25 mm Hg 25 mm Hg 25 mm Hg 25 mm Hg 18 mm Hg NFP = +10 mm Hg NFP = 0 NFP = −7 mm Hg CHP > BCOP Fluid forced out of capillary CHP = BCOP No net movement of fluid BCOP > CHP Fluid moves into capillary
  102. 102. © 2012 Pearson Education, Inc. 21-2 Pressure and Resistance • Capillary Dynamics • Hemorrhaging • Reduces CHP and NFP • Increases reabsorption of interstitial fluid (recall of fluids) • Dehydration • Increases BCOP • Accelerates reabsorption • Increase in CHP or BCOP • Fluid moves out of blood • Builds up in peripheral tissues (edema)
  103. 103. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Tissue Perfusion • Blood flow through the tissues • Carries O2 and nutrients to tissues and organs • Carries CO2 and wastes away • Is affected by: 1. Cardiac output 2. Peripheral resistance 3. Blood pressure
  104. 104. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Cardiovascular Regulation Changes Blood Flow to a Specific Area 1. At an appropriate time 2. In the right area 3. Without changing blood pressure and blood flow to vital organs
  105. 105. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Controlling Cardiac Output and Blood Pressure • Autoregulation • Causes immediate, localized homeostatic adjustments • Neural mechanisms • Respond quickly to changes at specific sites • Endocrine mechanisms • Direct long-term changes
  106. 106. © 2012 Pearson Education, Inc. Figure 21-14 Short-Term and Long-Term Cardiovascular Responses Autoregulation Local vasodilators released HOMEOSTASIS RESTORED HOMEOSTASIS DISTURBED HOMEOSTASIS Local decrease in resistance and increase in blood flow Inadequate local blood pressure and blood flow Normal blood pressure and volume • Physical stress (trauma, high temperature) • Chemical changes (decreased O2 or pH, increased CO2 or prostaglandins) • Increased tissue activity Autoregulation is due to opening and closing precapillary sphincters due to local release of vasodilator or vasoconstrictor chemicals from the tissue. Start
  107. 107. © 2012 Pearson Education, Inc. Figure 21-14 Short-Term and Long-Term Cardiovascular Responses Central Regulation Stimulation of receptors sensitive to changes in systemic blood pressure or chemistry Endocrine mechanisms HOMEOSTASIS RESTORED Neural mechanisms Activation of cardiovascular centers Stimulation of endocrine response Long-term increase in blood volume and blood pressure Short-term elevation of blood pressure by sympathetic stimulation of the heart and peripheral vasoconstriction Central regulation involves neuroendocrine mechanisms that control the total systemic circulation. This regulation involves both the cardiovascular centers and the vasomotor centers. If autoregulation is ineffective
  108. 108. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Autoregulation of Blood Flow within Tissues • Adjusted by peripheral resistance while cardiac output stays the same • Local vasodilators accelerate blood flow at tissue level • Low O2 or high CO2 levels • Low pH (acids) • Nitric oxide (NO) • High K+ or H+ concentrations • Chemicals released by inflammation (histamine) • Elevated local temperature
  109. 109. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Autoregulation of Blood Flow within Tissues • Adjusted by peripheral resistance while cardiac output stays the same • Local vasoconstrictors • Examples: prostaglandins and thromboxanes • Released by damaged tissues • Constrict precapillary sphincters • Affect a single capillary bed
  110. 110. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Neural Mechanisms • Cardiovascular (CV) centers of the medulla oblongata • Cardiac centers • Cardioacceleratory center increases cardiac output • Cardioinhibitory center reduces cardiac output
  111. 111. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Vasomotor Center 1. Control of vasoconstriction • Controlled by adrenergic nerves (NE) • Stimulates smooth muscle contraction in arteriole walls 2. Control of vasodilation • Controlled by cholinergic nerves (NO) • Relaxes smooth muscle • Vasomotor Tone • Produced by constant action of sympathetic vasoconstrictor nerves
  112. 112. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Reflex Control of Cardiovascular Function • Cardiovascular centers monitor arterial blood • Baroreceptor reflexes • Respond to changes in blood pressure • Chemoreceptor reflexes • Respond to changes in chemical composition, particularly pH and dissolved gases
  113. 113. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Baroreceptor Reflexes • Stretch receptors in walls of: 1. Carotid sinuses (maintain blood flow to brain) 2. Aortic sinuses (monitor start of systemic circuit) 3. Right atrium (monitors end of systemic circuit)
  114. 114. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Baroreceptor Reflexes • When blood pressure rises, CV centers: 1. Decrease cardiac output 2. Cause peripheral vasodilation • When blood pressure falls, CV centers: 1. Increase cardiac output 2. Cause peripheral vasoconstriction
  115. 115. © 2012 Pearson Education, Inc. Figure 21-15 Baroreceptor Reflexes of the Carotid and Aortic Sinuses Responses to Increased Baroreceptor Stimulation Baroreceptors stimulated HOMEOSTASIS DISTURBED Rising blood pressure Cardioinhibitory centers stimulated Cardioacceleratory centers inhibited Vasomotor centers inhibited Decreased cardiac output Vasodilation occurs HOMEOSTASIS RESTORED Blood pressure declines HOMEOSTASIS Normal range of blood pressure Start
  116. 116. © 2012 Pearson Education, Inc. Figure 21-15 Baroreceptor Reflexes of the Carotid and Aortic Sinuses HOMEOSTASIS Normal range of blood pressure HOMEOSTASIS DISTURBED HOMEOSTASIS RESTORED Falling blood pressure Blood pressure rises Baroreceptors inhibited Vasoconstriction occurs Increased cardiac output Vasomotor centers stimulated Cardioacceleratory centers stimulated Cardioinhibitory centers inhibited Responses to Decreased Baroreceptor Stimulation Start
  117. 117. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Chemoreceptor Reflexes • Peripheral chemoreceptors in carotid bodies and aortic bodies monitor blood • Central chemoreceptors below medulla oblongata: • Monitor cerebrospinal fluid • Control respiratory function • Control blood flow to brain
  118. 118. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Chemoreceptor Reflexes • Changes in pH, O2, and CO2 concentrations • Produced by coordinating cardiovascular and respiratory activities
  119. 119. © 2012 Pearson Education, Inc. Figure 21-16 The Chemoreceptor Reflexes Increasing CO2 levels, decreasing pH and O2 levels Respiratory centers in the medulla oblongata stimulated Respiratory rate increases Increased cardiac output and blood pressure Cardioacceleratory centers stimulated Cardioinhibitory centers inhibited Respiratory Response Cardiovascular Responses Effects on Cardiovascular Centers Vasomotor centers stimulated Vasoconstriction occurs Normal pH, O2, and CO2 levels in blood and CSF HOMEOSTASIS Elevated CO2 levels, decreased pH and O2 levels in blood and CSF HOMEOSTASIS DISTURBED Start Decreased CO2 levels, increased pH and O2 levels in blood and CSF HOMEOSTASIS RESTORED Reflex Response Chemoreceptors stimulated
  120. 120. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • CNS Activities and the Cardiovascular Centers • Thought processes and emotional states can elevate blood pressure by: • Cardiac stimulation and vasoconstriction
  121. 121. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Hormones and Cardiovascular Regulation • Hormones have short-term and long-term effects on cardiovascular regulation • For example, E and NE from adrenal medullae stimulate cardiac output and peripheral vasoconstriction
  122. 122. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Antidiuretic Hormone (ADH) • Released by neurohypophysis (posterior lobe of pituitary) • Elevates blood pressure • Reduces water loss at kidneys • ADH responds to: • Low blood volume • High plasma osmotic concentration • Circulating angiotensin II
  123. 123. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Angiotensin II • Responds to fall in renal blood pressure • Stimulates: 1. Aldosterone production 2. ADH production 3. Thirst 4. Cardiac output and peripheral vasoconstriction
  124. 124. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Erythropoietin (EPO) • Released at kidneys • Responds to low blood pressure, low O2 content in blood • Stimulates red blood cell production
  125. 125. © 2012 Pearson Education, Inc. Figure 21-17a The Hormonal Regulation of Blood Pressure and Blood Volume HOMEOSTASIS Factors that compensate for decreased blood pressure and volume Increased red blood cell formation Thirst stimulated Antidiuretic hormone released Angiotensin II Effects Combined Short-Term and Long-Term Effects Endocrine Response of Kidneys Renin release leads to angiotensin II activation Erythropoietin (EPO) is released Increased cardiac output and peripheral vasoconstriction Sympathetic activation and release of adrenal hormones E and NE Long-term Short-term Increased blood pressure Increased blood volume Decreasing blood pressure and volume Start Blood pressure and volume fall HOMEOSTASIS DISTURBED HOMEOSTASIS RESTORED Normal blood pressure and volume Blood pressure and volume rise Aldosterone secreted Angiotensin II
  126. 126. © 2012 Pearson Education, Inc. 21-3 Cardiovascular Regulation • Natriuretic Peptides • Atrial natriuretic peptide (ANP) • Produced by cells in right atrium • Brain natriuretic peptide (BNP) • Produced by ventricular muscle cells • Respond to excessive diastolic stretching • Lower blood volume and blood pressure • Reduce stress on heart
  127. 127. © 2012 Pearson Education, Inc. Figure 21-17b The Hormonal Regulation of Blood Pressure and Blood Volume HOMEOSTASIS Factors that compensate for increased blood pressure and volume Increasing blood pressure and volume HOMEOSTASIS RESTORED Declining blood pressure and volume Normal blood pressure and volume HOMEOSTASIS DISTURBED Rising blood pressure and volume Natriuretic peptides released by the heart Increased water loss in urine Reduced thirst Inhibition of ADH, aldosterone, epinephrine, and norepinephrine release Peripheral vasodilation Reduced blood volume Combined Effects Increased Na+ loss in urine Responses to ANP and BNP
  128. 128. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • Blood, Heart, and Cardiovascular System • Work together as unit • Respond to physical and physiological changes (for example, exercise and blood loss) • Maintain homeostasis
  129. 129. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • The Cardiovascular Response to Exercise • Light Exercise • Extensive vasodilation occurs increasing circulation • Venous return increases with muscle contractions • Cardiac output rises 1. Venous return (Frank–Starling principle) 2. Atrial stretching
  130. 130. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • The Cardiovascular Response to Exercise • Heavy Exercise • Activates sympathetic nervous system • Cardiac output increases to maximum • About four times resting level • Restricts blood flow to “nonessential” organs (e.g., digestive system) • Redirects blood flow to skeletal muscles, lungs, and heart • Blood supply to brain is unaffected
  131. 131. © 2012 Pearson Education, Inc. Table 21-2 Changes in Blood Distribution during Exercise
  132. 132. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • Exercise, Cardiovascular Fitness, and Health • Regular moderate exercise • Lowers total blood cholesterol levels • Intense exercise • Can cause severe physiological stress
  133. 133. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation Table 21-3 Effects of Training on Cardiovascular Performance Subject Heart Weight (g) Stroke Volume (mL) Heart Rate (BPM) Cardiac Output (L/min) Blood Pressure (systolic/ diastolic) Nonathlete (rest) 300 60 83 5.0 120/80 Nonathlete (maximum) 104 192 19.9 187/75 Trained athlete (rest) 500 100 53 5.3 120/80 Trained athlete (maximum) 167 182 30.4 200/90* *Diastolic pressures of athletes during maximum activity have not been accurately measured.
  134. 134. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • The Cardiovascular Response to Hemorrhaging • Entire cardiovascular system adjusts to: • Maintain blood pressure • Restore blood volume
  135. 135. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • Short-Term Elevation of Blood Pressure • Carotid and aortic reflexes • Increase cardiac output (increasing heart rate) • Cause peripheral vasoconstriction • Sympathetic nervous system • Triggers hypothalamus • Further constricts arterioles • Venoconstriction improves venous return
  136. 136. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • Short-Term Elevation of Blood Pressure • Hormonal effects • Increase cardiac output • Increase peripheral vasoconstriction (E, NE, ADH, angiotensin II)
  137. 137. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • Shock • Short-term responses compensate after blood losses of up to 20% of total blood volume • Failure to restore blood pressure results in shock
  138. 138. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • Long-Term Restoration of Blood Volume • Recall of fluids from interstitial spaces • Aldosterone and ADH promote fluid retention and reabsorption • Thirst increases • Erythropoietin stimulates red blood cell production
  139. 139. © 2012 Pearson Education, Inc. Figure 21-18 Cardiovascular Responses to Hemorrhaging and Blood Loss Normal blood pressure and volume Extensive bleeding reduces blood pressure and volume HOMEOSTASIS DISTURBED Responses coordinated by the endocrine system Responses directed by the nervous system Falling blood pressure and volume Long-Term Hormonal Response ADH, angiotensin II, aldosterone, and EPO released Blood pressure and volume rise HOMEOSTASIS RESTORED Cardiovascular Responses Peripheral vasoconstriction; mobilization of venous reserve Increased cardiac output Elevation of blood volume Stimulation of baroreceptors and chemoreceptorsPain, stress, anxiety, fear Higher Centers Stimulation of cardiovascular centers General sympathetic activation HOMEOSTASIS
  140. 140. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • Vascular Supply to Special Regions • Through organs with separate mechanisms to control blood flow • Three important examples 1. Brain 2. Heart 3. Lungs
  141. 141. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • Blood Flow to the Brain • Is top priority • Brain has high oxygen demand • When peripheral vessels constrict, cerebral vessels dilate, normalizing blood flow
  142. 142. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • Stroke • Also called cerebrovascular accident (CVA) • Blockage or rupture in a cerebral artery • Stops blood flow
  143. 143. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • Blood Flow to the Heart • Through coronary arteries • Oxygen demand increases with activity • Lactic acid and low O2 levels • Dilate coronary vessels • Increase coronary blood flow
  144. 144. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • Blood Flow to the Heart • Epinephrine • Dilates coronary vessels • Increases heart rate • Strengthens contractions
  145. 145. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • Heart Attack • A blockage of coronary blood flow • Can cause: • Angina (chest pain) • Tissue damage • Heart failure • Death
  146. 146. © 2012 Pearson Education, Inc. 21-4 Cardiovascular Adaptation • Blood Flow to the Lungs • Regulated by O2 levels in alveoli • High O2 content • Vessels dilate • Low O2 content • Vessels constrict
  147. 147. © 2012 Pearson Education, Inc. 21-5 Pulmonary and Systemic Patterns • Three General Functional Patterns 1. Peripheral artery and vein distribution is the same on right and left, except near the heart 2. The same vessel may have different names in different locations 3. Tissues and organs usually have multiple arteries and veins • Vessels may be interconnected with anastomoses
  148. 148. © 2012 Pearson Education, Inc. Figure 21-19 A Schematic Overview of the Pattern of Circulation Brain Upper limbs Lungs Pulmonary circuit (veins) LA Left ventricle Systemic circuit (arteries) Kidneys Spleen Digestive organs Gonads Lower limbs Liver
  149. 149. © 2012 Pearson Education, Inc. Figure 21-19 A Schematic Overview of the Pattern of Circulation Brain Upper limbs Lungs Pulmonary circuit (arteries) RA Right ventricle Systemic circuit (veins) Kidneys Liver Digestive organs Gonads Lower limbs
  150. 150. © 2012 Pearson Education, Inc. 21-6 The Pulmonary Circuit • Deoxygenated Blood Arrives at Heart from Systemic Circuit • Passes through right atrium and right ventricle • Enters pulmonary trunk • At the lungs • CO2 is removed • O2 is added • Oxygenated blood • Returns to the heart • Is distributed to systemic circuit
  151. 151. © 2012 Pearson Education, Inc. 21-6 The Pulmonary Circuit • Pulmonary Vessels • Pulmonary arteries • Carry deoxygenated blood • Pulmonary trunk • Branches to left and right pulmonary arteries • Pulmonary arteries • Branch into pulmonary arterioles • Pulmonary arterioles • Branch into capillary networks that surround alveoli
  152. 152. © 2012 Pearson Education, Inc. 21-6 The Pulmonary Circuit • Pulmonary Vessels • Pulmonary veins • Carry oxygenated blood • Capillary networks around alveoli • Join to form venules • Venules • Join to form four pulmonary veins • Pulmonary veins • Empty into left atrium
  153. 153. © 2012 Pearson Education, Inc. Figure 21-20 The Pulmonary Circuit Ascending aorta Superior vena cava Right lung Right pulmonary arteries Right pulmonary veins Inferior vena cava Descending aorta
  154. 154. © 2012 Pearson Education, Inc. Figure 21-20 The Pulmonary Circuit Aortic arch Pulmonary trunk Left lung Left pulmonary arteries Left pulmonary veins Alveolus Capillary CO2 O2
  155. 155. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The Systemic Circuit • Contains 84% of blood volume • Supplies entire body • Except for pulmonary circuit
  156. 156. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • Systemic Arteries • Blood moves from left ventricle • Into ascending aorta • Coronary arteries • Branch from aortic sinus
  157. 157. © 2012 Pearson Education, Inc. Figure 21-21 An Overview of the Major Systemic Arteries Vertebral Right subclavian Brachiocephalic trunk Ascending aorta Aortic arch Celiac trunk Brachial Right common carotid Left common carotid Left subclavian Axillary Pulmonary trunk Descending aorta Diaphragm Renal Superior mesenteric Gonadal Inferior mesenteric Common iliac Internal iliac Radial Ulnar External iliac Femoral Palmar arches Deep femoral
  158. 158. © 2012 Pearson Education, Inc. Figure 21-21 An Overview of the Major Systemic Arteries Femoral Popliteal Posterior tibial Anterior tibial Fibular Plantar arch Descending genicular Dorsalis pedis
  159. 159. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The Aorta • The ascending aorta • Rises from the left ventricle • Curves to form aortic arch • Turns downward to become descending aorta
  160. 160. © 2012 Pearson Education, Inc. Figure 21-22a Arteries of the Chest and Upper Limb Suprascapular Thyrocervical trunk Right subclavian Axillary Lateral thoracic Anterior humeral circumflex Posterior humeral circumflex Subscapular Deep brachial Intercostal arteries Brachial Ulnar recurrent arteries Right common carotid Left common carotid Vertebral Brachiocephalic trunk Left subclavian Aortic arch Ascending aorta Thoracic aorta Heart Internal thoracic Abdominal aorta Ulnar collateral arteries Thoracoacromial Arteries of the chest and upper limb, a diagrammatic view
  161. 161. © 2012 Pearson Education, Inc. Figure 21-22b Arteries of the Chest and Upper Limb Right vertebral Right common carotid Left common carotid Left vertebral Left thyrocervical trunkLeft subclavian Brachiocephalic trunk Right thyrocervical trunk Right subclavian Right axillary Right internal thoracic Left internal thoracic Left axillary AORTIC ARCH ASCENDING AORTA THORACIC AORTA (see Fig. 21−25) Left brachial Left ulnar Left radial ABDOMINAL AORTA (see Fig. 21−26) LEFT VENTRICLE Right brachial Right radial Right ulnar Connected by anastomoses of palmar arches that supply digital arteries To structures of the arm Forearm, radial side Forearm, ulnar side Muscles of the right pectoral region and axilla Skin and muscles of chest and abdomen, mammary gland (right side), pericardium Spinal cord, cervical vertebrae (right side); fuses with left vertebral, forming basilar artery after entering cranium via foramen magnum Muscles, skin, tissues of neck, thyroid gland, shoulders, and upper back (right side) A flowchart of the arteries of the chest and upper limb
  162. 162. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • Branches of the Aortic Arch • Deliver blood to head, neck, shoulders, and upper limbs 1. Brachiocephalic trunk 2. Left common carotid artery 3. Left subclavian artery
  163. 163. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The Subclavian Arteries • Leaving the thoracic cavity: • Become axillary artery in arm • And brachial artery distally
  164. 164. © 2012 Pearson Education, Inc. Figure 21-22a Arteries of the Chest and Upper Limb Suprascapular Thyrocervical trunk Right subclavian Axillary Lateral thoracic Anterior humeral circumflex Posterior humeral circumflex Subscapular Deep brachial Intercostal arteries Brachial Ulnar recurrent arteries Right common carotid Left common carotid Vertebral Brachiocephalic trunk Left subclavian Aortic arch Ascending aorta Thoracic aorta Heart Internal thoracic Abdominal aorta Ulnar collateral arteries Thoracoacromial Arteries of the chest and upper limb, a diagrammatic view
  165. 165. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The Brachial Artery • Divides at coronoid fossa of humerus • Into radial artery and ulnar artery • Fuse at wrist to form: • Superficial and deep palmar arches • Which supply digital arteries
  166. 166. © 2012 Pearson Education, Inc. Figure 21-22a Arteries of the Chest and Upper Limb Arteries of the chest and upper limb, a diagrammatic view Radial Anterior crural interosseous Ulnar Deep palmar arch Superficial palmar arch Digital arteries
  167. 167. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The Common Carotid Arteries • Each common carotid divides into: • External carotid artery - supplies blood to structures of the neck, lower jaw, and face • Internal carotid artery - enters skull and delivers blood to brain • Divides into three branches 1. Ophthalmic artery 2. Anterior cerebral artery 3. Middle cerebral artery
  168. 168. © 2012 Pearson Education, Inc. Figure 21-23 Arteries of the Neck and Head Second rib Internal thoracic Axillary Subclavian Suprascapular Transverse cervical Thyrocervical trunk Carotid sinus Vertebral Internal carotid Inferior thyroid Basilar Posterior cerebral Carotid canal Cerebral arterial circle Ophthalmic Middle cerebral Anterior cerebral ClavicleFirst rib
  169. 169. © 2012 Pearson Education, Inc. Figure 21-23 Arteries of the Neck and Head Branches of the External Carotid Superficial temporal Maxillary Occipital Facial Lingual External carotid Common carotid Brachiocephalic trunk ClavicleFirst rib
  170. 170. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The Vertebral Arteries • Also supply brain with blood • Left and right vertebral arteries • Arise from subclavian arteries • Enter cranium through foramen magnum • Fuse to form basilar artery • Branches to form posterior cerebral arteries • Posterior cerebral arteries • Become posterior communicating arteries
  171. 171. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • Anastomoses • The cerebral arterial circle (or circle of Willis) interconnects: • The internal carotid arteries • And the basilar artery
  172. 172. © 2012 Pearson Education, Inc. Figure 21-24a Arteries of the Brain Anterior cerebral Ophthalmic Internal carotid (cut) Middle cerebral Pituitary gland Posterior cerebral Cerebellar Anterior communicating Cerebral Arterial Circle Anterior cerebral Posterior communicating Posterior cerebral Basilar Vertebral Inferior surface
  173. 173. © 2012 Pearson Education, Inc. Figure 21-24b Arteries of the Brain Middle cerebral Anterior cerebral Ophthalmic Cerebral arterial circle Internal carotid Lateral view Posterior cerebral Basilar Vertebral
  174. 174. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The Descending Aorta • Thoracic aorta • Supplies organs of the chest • Bronchial arteries • Pericardial arteries • Esophageal arteries • Mediastinal arteries • Supplies chest wall • Intercostal arteries • Superior phrenic arteries
  175. 175. © 2012 Pearson Education, Inc. Figure 21-25a Major Arteries of the Trunk Aortic arch Internal thoracic Thoracic aorta Somatic Branches of the Thoracic Aorta Intercostal arteries Superior phrenic Inferior phrenic A diagrammatic view, with most of the thoracic and abdominal organs removed
  176. 176. © 2012 Pearson Education, Inc. Figure 21-25a Major Arteries of the Trunk Visceral Branches of the Thoracic Aorta Bronchial arteries Esophageal arteries Mediastinal arteries Pericardial arteries A diagrammatic view, with most of the thoracic and abdominal organs removed
  177. 177. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The Descending Aorta • Abdominal Aorta • Divides at terminal segment of the aorta into: • Left common iliac artery • Right common iliac artery • Unpaired branches • Major branches to visceral organs • Paired branches • To body wall • Kidneys • Urinary bladder • Structures outside abdominopelvic cavity
  178. 178. © 2012 Pearson Education, Inc. Figure 21-25a Major Arteries of the Trunk A diagrammatic view, with most of the thoracic and abdominal organs removed Diaphragm Adrenal Renal Gonadal Lumbar Terminal segment of the aorta Common iliac Median sacral
  179. 179. © 2012 Pearson Education, Inc. Figure 21-25a Major Arteries of the Trunk Celiac Trunk Left gastric Splenic Common hepatic Superior mesenteric Abdominal aorta Inferior mesenteric A diagrammatic view, with most of the thoracic and abdominal organs removed
  180. 180. © 2012 Pearson Education, Inc. Figure 21-26 Arteries Supplying the Abdominopelvic Organs Branches of the Common Hepatic Artery Hepatic artery proper (liver) Gastroduodenal (stomach and duodenum) Cystic (gallbladder) Right gastric (stomach) Right gastroepiploid (stomach and duodenum) Superior pancreatico- duodenal (duodenum) Ascending colon Superior Mesenteric Artery Inferior pancreatico- duodenal (pancreas and duodenum) Middle colic (cut) (large intestine) Right colic (large intestine) Ileocolic (large intestine) Intestinal arteries (small intestine) Liver Pancreas Small intestine Rectum
  181. 181. © 2012 Pearson Education, Inc. Figure 21-26 Arteries Supplying the Abdominopelvic Organs Stomach The Celiac Trunk Common hepatic Left gastric Splenic Spleen Branches of the Splenic Artery Left gastroepiploic (stomach) Pancreatic (pancreas) Inferior Mesenteric Artery Left colic (colon) Sigmoid (colon) Rectal (rectum) Sigmoid colon Rectum Small intestine Pancreas
  182. 182. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • Arteries of the Pelvis and Lower Limbs • Femoral artery • Deep femoral artery • Becomes popliteal artery • Posterior to knee • Branches to form: • Posterior and anterior tibial arteries • Posterior gives rise to fibular artery
  183. 183. © 2012 Pearson Education, Inc. Figure 21-25b Major Arteries of the Trunk A flowchart showing major arteries of the trunk Left common iliac Pelvis and left lower limb Pelvis and right lower limb Right common iliac Right external iliac Left internal iliac Left external iliac Right internal iliac Superior gluteal Obturator Internal pudendal Lateral sacral Lateral rotators of hip; rectum, anus, perineal muscles, external genitaliaIlium, hip and thigh muscles, hip joint and femoral head Hip muscles, hip joint Pelvic muscles, skin, viscera of pelvis (urinary and reproductive organs), perineum, gluteal region, and medial thigh Skin and muscles of sacrum
  184. 184. © 2012 Pearson Education, Inc. Figure 21-27a Arteries of the Lower Limb Common iliac External iliac Superior gluteal Inguinal ligament Deep femoral Lateral femoral circumflex Medial femoral circumflex Femoral Internal iliac Lateral sacral Internal pudendal Obturator Descending genicular Anterior view
  185. 185. © 2012 Pearson Education, Inc. Figure 21-27a Arteries of the Lower Limb Anterior view Popliteal Anterior tibial Posterior tibial Fibular Dorsalis pedis Medial plantar Lateral plantar Dorsal arch Plantar arch
  186. 186. © 2012 Pearson Education, Inc. Figure 21-27b Arteries of the Lower Limb Posterior view Medial femoral circumflex Femoral Internal pudendal Obturator Superior gluteal Right external iliac Deep femoral Lateral femoral circumflex Descending genicular
  187. 187. © 2012 Pearson Education, Inc. Figure 21-27b Arteries of the Lower Limb Posterior view Popliteal Anterior tibial Posterior tibial Fibular
  188. 188. © 2012 Pearson Education, Inc. Figure 21-27c Arteries of the Lower Limb Deep femoral Femoral Descending genicular Popliteal Fibular Posterior tibial Anterior tibial Medial femoral circumflex Lateral femoral circumflex Thigh Hip joint, femoral head, deep muscles of the thigh Skin of leg, knee joint Leg and footQuadriceps muscles Adductor muscles, obturator muscles, hip joint Connected by anastomoses of dorsalis pedis, dorsal arch, and plantar arch, which supply distal portions of the foot and the toes EXTERNAL ILIAC A flowchart of blood flow to a lower limb
  189. 189. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • Systemic Veins • Complementary Arteries and Veins • Run side by side • Branching patterns of peripheral veins are more variable • In neck and limbs • One set of arteries (deep) • Two sets of veins (one deep, one superficial) • Venous system controls body temperature
  190. 190. © 2012 Pearson Education, Inc. Figure 21-28 An Overview of the Major Systemic Veins Vertebral External jugular Internal jugular Brachiocephalic Superior vena cava Intercostal veins Inferior vena cava Renal Gonadal Subclavian Axillary Brachial Basilic Hepatic veins Median cubital Radial Ulnar Median antebrachial Palmar venous arches Digital veins Lumbar veins Left and right common iliac External iliac Internal iliac Deep femoral Femoral Superficial veins Deep veins KEY
  191. 191. © 2012 Pearson Education, Inc. Figure 21-28 An Overview of the Major Systemic Veins Superficial veins Deep veins KEY Femoral Posterior tibial Anterior tibial Great saphenous Popliteal Small saphenous Fibular Plantar venous arch Dorsal venous arch
  192. 192. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The Superior Vena Cava (SVC) • Receives blood from the tissues and organs of: • Head • Neck • Chest • Shoulders • Upper limbs
  193. 193. © 2012 Pearson Education, Inc. Figure 21-29c Major Veins of the Head, Neck, and Brain Superior sagittal sinus Superficial cerebral veins Inferior sagittal sinus Great cerebral Straight sinus Petrosal sinuses Right transverse sinus Occipital sinus Sigmoid sinus Occipital Temporal Deep cerebral Cavernous sinus Maxillary Facial Vertebral External jugular Right subclavian Axillary Clavicle First rib Veins draining the brain and the superficial and deep portions of the head and neck. Internal jugular Right brachiocephalic Left brachiocephalic Superior vena cava Internal thoracic
  194. 194. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The Dural Sinuses • Superficial cerebral veins and small veins of the brain stem • Empty into network of dural sinuses • Superior and inferior sagittal sinuses • Petrosal sinuses • Occipital sinus • Left and right transverse sinuses • Straight sinus
  195. 195. © 2012 Pearson Education, Inc. Figure 21-29b Major Veins of the Head, Neck, and Brain Straight sinus Occipital sinus Right transverse sinus Right sigmoid sinus Inferior sagittal sinus Superior sagittal sinus Great cerebral vein Cavernous sinus Petrosal sinuses Internal jugular Vertebral vein A lateral view of the brain showing the venous distribution.
  196. 196. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • Cerebral Veins • Great cerebral vein • Drains to straight sinus • Other cerebral veins • Drain to cavernous sinus • Which drains to petrosal sinus • Vertebral Veins • Empty into brachiocephalic veins of chest
  197. 197. © 2012 Pearson Education, Inc. Figure 21-29a Major Veins of the Head, Neck, and Brain An inferior view of the brain, showing the venous distribution. Occipital sinus Straight sinus Transverse sinus Cerebellar veins Sigmoid sinus Internal jugular Cerebral veins Cavernous sinus Petrosal sinus Superior sagittal, sinus (cut)
  198. 198. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • Superficial Veins of the Head and Neck • Converge to form: • Temporal, facial, and maxillary veins • Temporal and maxillary veins • Drain to external jugular vein • Facial vein • Drains to internal jugular vein
  199. 199. © 2012 Pearson Education, Inc. Figure 21-29c Major Veins of the Head, Neck, and Brain Superior sagittal sinus Superficial cerebral veins Inferior sagittal sinus Great cerebral Straight sinus Petrosal sinuses Right transverse sinus Occipital sinus Sigmoid sinus Occipital Temporal Deep cerebral Cavernous sinus Maxillary Facial Vertebral External jugular Right subclavian Axillary Clavicle First rib Veins draining the brain and the superficial and deep portions of the head and neck. Internal jugular Right brachiocephalic Left brachiocephalic Superior vena cava Internal thoracic
  200. 200. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • Veins of the Hand • Digital veins • Empty into superficial and deep palmar veins • Which interconnect to form palmar venous arches
  201. 201. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • Veins of the Hand • Superficial arch empties into: • Cephalic vein • Median antebrachial vein • Basilic vein • Median cubital vein • Deep palmar veins drain into: • Radial and ulnar veins • Which fuse above elbow to form brachial vein
  202. 202. © 2012 Pearson Education, Inc. Figure 21-30 The Venous Drainage of the Abdomen and Chest Palmar venous arches Digital veins Ulnar Median antebrachial Radial Cephalic Anterior crural interosseous Basilic Median cubital Deep veins Superficial veins KEY
  203. 203. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The Brachial Vein • Merges with basilic vein • To become axillary vein • Cephalic vein joins axillary vein • To form subclavian vein • Merges with external and internal jugular veins • To form brachiocephalic vein • Which enters thoracic cavity
  204. 204. © 2012 Pearson Education, Inc. Figure 21-30 The Venous Drainage of the Abdomen and Chest Deep veins Superficial veins KEY Adrenal veins Phrenic veins Basilic INFERIOR VENA CAVA Intercostal veins Hemiazygos Accessory hemiazygos Cephalic Axillary Brachiocephalic Highest intercostal Subclavian External jugular Internal jugular Vertebral Brachial
  205. 205. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • Veins of the Thoracic Cavity • Brachiocephalic vein receives blood from: • Vertebral vein • Internal thoracic vein • The Left and Right Brachiocephalic Veins • Merge to form the superior vena cava (SVC)
  206. 206. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • Tributaries of the Superior Vena Cava • Azygos vein and hemiazygos vein, which receive blood from: 1. Intercostal veins 2. Esophageal veins 3. Veins of other mediastinal structures
  207. 207. © 2012 Pearson Education, Inc. Figure 21-30 The Venous Drainage of the Abdomen and Chest Medial sacral Deep veins Superficial veins KEY External iliac Internal iliac Common iliac Lumbar veins Gonadal veins Renal veins Hepatic veins Internal thoracic Azygos Esophageal veins Mediastinal veins SUPERIOR VENA CAVA
  208. 208. © 2012 Pearson Education, Inc. Figure 21-31a Flowcharts of Circulation to the Superior and Inferior Venae Cavae Tributaries of the superior vena cava Right vertebral Collect blood from vertebrae and body wall Left intercostal veins Hemiazygos Left brachiocephalic Collects blood from cranium, face, and neck Collect blood from structures of anterior thoracic wall Left internal jugular Right internal jugular Left and right internal thoracic veins Esophageal veins Azygos Collect blood from the mediastinum Right external jugular Right subclavian Right axillary Mediastinal veins Right brachiocephalic Veins of the right upper limb Right intercostal veins Collect blood from vertebrae and body wall Collect blood from the eophagus KEY Superficial veins Deep veins SUPERIOR VENA CAVA RIGHT ATRIUM Collects blood from cranium, spinal cord, vertebrae Left vertebral Through highest intercostal vein
  209. 209. © 2012 Pearson Education, Inc. Figure 21-31a Flowcharts of Circulation to the Superior and Inferior Venae Cavae Tributaries of the superior vena cava KEY Superficial veins Deep veins Venous network of wrist and hand Left cephalic Left basilic Left axillary Left brachial Left subclavian Left brachiocephalic Left external jugular Left ulnar Left radial Radial side of forearm Ulnar side of forearm Collects blood from lateral surface of upper limb Collects blood from medial surface of upper limb Collects blood from forearm, wrist, and hand Collects blood from neck, face, salivary glands, scalp Interconnected by median cubital vein and median antebrachial network
  210. 210. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The Inferior Vena Cava (IVC) • Collects blood from organs inferior to the diaphragm
  211. 211. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • Veins of the Foot • Capillaries of the sole • Drain into a network of plantar veins • Which supply the plantar venous arch • Drain into deep veins of leg: • Anterior tibial vein • Posterior tibial vein • Fibular vein • All three join to become popliteal vein
  212. 212. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The Dorsal Venous Arch • Collects blood from: • Superior surface of foot • Digital veins • Drains into two superficial veins 1. Great saphenous vein (drains into femoral vein) 2. Small saphenous vein (drains into popliteal vein)
  213. 213. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The Popliteal Vein • Becomes the femoral vein • Before entering abdominal wall, receives blood from: • Great saphenous vein • Deep femoral vein • Femoral circumflex vein • Inside the pelvic cavity • Becomes the external iliac vein
  214. 214. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The External Iliac Veins • Are joined by internal iliac veins • To form right and left common iliac veins • The right and left common iliac veins • Merge to form the inferior vena cava
  215. 215. © 2012 Pearson Education, Inc. Figure 21-32a Venous Drainage from the Lower Limb External iliac Common iliac Internal iliac Gluteal Internal pudendal Lateral sacral Obturator Femoral Femoral circumflex Deep femoral Femoral Great saphenous Popliteal Small saphenous Anterior tibial Posterior tibial Fibular Dorsal venous arch Plantar venous arch Digital An anterior view
  216. 216. © 2012 Pearson Education, Inc. Figure 21-32b Venous Drainage from the Lower Limb External iliac Gluteal Internal pudendal Obturator Femoral Femoral circumflex Deep femoral Femoral Great saphenous Popliteal Small saphenous Anterior tibial Posterior tibial Fibular A posterior view
  217. 217. © 2012 Pearson Education, Inc. Figure 21-32c Venous Drainage from the Lower Limb EXTERNAL ILIAC Small saphenous Femoral Popliteal Fibular Posterior tibial Anterior tibial Extensive anastomoses interconnect veins of the ankle and foot Great saphenous KEY Superficial veins Deep veins Collects blood from the superficial veins of the lower limb Collects blood from the thigh Collects blood from superficial veins of the leg and foot A flowchart of venous circulation from a lower limb Deep femoral
  218. 218. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • Major Tributaries of the Abdominal Inferior Vena Cava 1. Lumbar veins 2. Gonadal veins 3. Hepatic veins 4. Renal veins 5. Adrenal veins 6. Phrenic veins
  219. 219. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • The Hepatic Portal System • Connects two capillary beds • Delivers nutrient-laden blood • From capillaries of digestive organs • To liver sinusoids for processing
  220. 220. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit Tributaries of the Hepatic Portal Vein 1. Inferior mesenteric vein • Drains part of large intestine 2. Splenic vein • Drains spleen, part of stomach, and pancreas 3. Superior mesenteric vein • Drains part of stomach, small intestine, and part of large intestine 4. Left and right gastric veins • Drain part of stomach • Cystic vein • Drains gallbladder
  221. 221. © 2012 Pearson Education, Inc. 21-7 The Systemic Circuit • Blood Processed in Liver • After processing in liver sinusoids (exchange vessels): • Blood collects in hepatic veins and empties into inferior vena cava
  222. 222. © 2012 Pearson Education, Inc. Figure 21-33 The Hepatic Portal System Inferior vena cava Hepatic Cystic Hepatic portal Pancreaticoduodenal Superior Mesenteric Vein and Its Tributaries Middle colic (from transverse colon) Right colic (ascending colon) Ileocolic (Ileum and ascending colon) Intestinal (small intestine) Pancreas Liver
  223. 223. © 2012 Pearson Education, Inc. Figure 21-33 The Hepatic Portal System Left gastric Right gastric Stomach Spleen Pancreas Left gastroepiploic (stomach) Right gastroepiploic (stomach) Pancreatic Descending colon Splenic Vein and Its Tributaries Inferior Mesenteric Vein and Its Tributaries Left colic (descending colon) Sigmoid (sigmoid colon) Superior rectal (rectum)
  224. 224. © 2012 Pearson Education, Inc. Figure 21-31b Flowcharts of Circulation to the Superior and Inferior Venae Cavae Tributaries of the inferior vena cava Superior gluteal veins Internal pudendal veins Obturator veins Lateral sacral veins Blood from veins in left lower limb Left external iliac Left internal iliac Right external iliac Right internal iliac Blood from veins in right lower limb Right common iliac Left common iliac Collect blood from the pelvic muscles, skin, urinary and reproductive organs of pelvic cavity Collect blood from the kidneys Collect blood from the diaphragm Collect blood from the adrenal glands Collect blood from the spinal cord and body wall Collect blood from the liver Collect blood from the gonads (testes or ovaries) Hepatic veins Gonadal veins Lumbar veins Phrenic veins Adrenal veins Renal veins RIGHT ATRIUM INFERIOR VENA CAVA KEY Superficial veins Deep veins
  225. 225. © 2012 Pearson Education, Inc. 21-8 Fetal and Maternal Circulation • Fetal and Maternal Cardiovascular Systems Promote the Exchange of Materials • Embryonic lungs and digestive tract nonfunctional • Respiratory functions and nutrition provided by placenta
  226. 226. © 2012 Pearson Education, Inc. 21-8 Fetal and Maternal Circulation • Placental Blood Supply • Blood flows to the placenta • Through a pair of umbilical arteries that arise from internal iliac arteries • Enters umbilical cord • Blood returns from placenta • In a single umbilical vein that drains into ductus venosus • Ductus venosus • Empties into inferior vena cava
  227. 227. © 2012 Pearson Education, Inc. 21-8 Fetal and Maternal Circulation • Before Birth • Fetal lungs are collapsed • O2 provided by placental circulation
  228. 228. © 2012 Pearson Education, Inc. 21-8 Fetal and Maternal Circulation • Fetal Pulmonary Circulation Bypasses • Foramen ovale • Interatrial opening • Covered by valve-like flap • Directs blood from right to left atrium • Ductus arteriosus • Short vessel • Connects pulmonary and aortic trunks
  229. 229. © 2012 Pearson Education, Inc. 21-8 Fetal and Maternal Circulation • Cardiovascular Changes at Birth • Newborn breathes air • Lungs expand • Pulmonary vessels expand • Reduced resistance allows blood flow • Rising O2 causes ductus arteriosus constriction • Rising left atrium pressure closes foramen ovale • Pulmonary circulation provides O2
  230. 230. © 2012 Pearson Education, Inc. Figure 21-34a Fetal Circulation Placenta Aorta Foramen ovale (open) Ductus arteriosus (open) Pulmonary trunk Liver Inferior vena cava Ductus venosus Umbilical vein Umbilical cord Blood flow to and from the placenta in full-term fetus (before birth) Umbilical arteries
  231. 231. © 2012 Pearson Education, Inc. Figure 21-34b Fetal Circulation Blood flow through the neonatal (newborn) heart after delivery Inferior vena cava Right ventricle Left ventricle Right atrium Foramen ovale (closed) Left atrium Pulmonary trunk Ductus arteriosus (closed)
  232. 232. © 2012 Pearson Education, Inc. Figure 21-35 Congenital Heart Problems Normal Heart Structure Most heart problems reflect deviations from the normal formation of the heart and its connections to the great vessels.
  233. 233. © 2012 Pearson Education, Inc. 21-8 Fetal and Maternal Circulation • Patent Foramen Ovale and Patent Ductus Arteriosus • In patent (open) foramen ovale blood recirculates through pulmonary circuit instead of entering left ventricle • The movement, driven by relatively high systemic pressure, is a “left-to-right shunt” • Arterial oxygen content is normal, but left ventricle must work much harder than usual to provide adequate blood flow through systemic circuit
  234. 234. © 2012 Pearson Education, Inc. 21-8 Fetal and Maternal Circulation • Patent Foramen Ovale and Patent Ductus Arteriosus • Pressures rise in the pulmonary circuit • If pulmonary pressures rise enough, they may force blood into systemic circuit through ductus arteriosus • A patent ductus arteriosus creates a “right-to-left shunt” • Because circulating blood is not adequately oxygenated, it develops deep red color • Skin develops blue tones typical of cyanosis and infant is known as a “blue baby”
  235. 235. © 2012 Pearson Education, Inc. Figure 21-35 Congenital Heart Problems Patent Foramen Ovale and Patent Ductus Arteriosus If the foramen ovale remains open, or patent, blood recirculates through the pulmonary circuit instead of entering the left ventricle. The movement, driven by the relatively high systemic pressure, is called a “left-to-right shunt.” Arterial oxygen content is normal, but the left ventricle must work much harder than usual to provide adequate blood flow through the systemic circuit. Hence, pressures rise in the pulmonary circuit. If the pulmonary pressures rise enough, they may force blood into the systemic circuit through the ductus arteriosus. This condition—a patent ductus arteriosus— creates a “right-to-left shunt.” Because the circulating blood is not adequately oxygenated, it develops a deep red color. The skin then develops the blue tones typical of cyanosis and the infant is known as a “blue baby.” Patent ductus arteriosus Patent foramen ovale
  236. 236. © 2012 Pearson Education, Inc. 21-8 Fetal and Maternal Circulation • Tetralogy of Fallot • Complex group of heart and circulatory defects that affect 0.10 percent of newborn infants 1. Pulmonary trunk is abnormally narrow (pulmonary stenosis) 2. Interventricular septum is incomplete 3. Aorta originates where interventricular septum normally ends 4. Right ventricle is enlarged and both ventricles thicken in response to increased workload
  237. 237. © 2012 Pearson Education, Inc. Figure 21-35 Congenital Heart Problems Tetralogy of Fallot ventricle is enlarged and both ventricles thicken in response to the increased workload. The tetralogy of Fallot (fa-LO) is a complex group of heart and circulatory defects that affect 0.10 percent of newborn infants. In this condition, (1) the pulmonary trunk is abnor- mally narrow (pulmonary stenosis), (2) the interventricular septum is incomplete, (3) the aorta originates where the interventricular septum normally ends, and (4) the right ¯ Patent ductus arteriosus Pulmonary stenosis Ventricular septal defect Enlarged right ventricle
  238. 238. © 2012 Pearson Education, Inc. 21-8 Fetal and Maternal Circulation • Ventricular Septal Defect • Openings in interventricular septum that separate right and left ventricles • The most common congenital heart problems, affecting 0.12 percent of newborns • Opening between the two ventricles has an effect similar to a connection between the atria • When more powerful left ventricle beats, it ejects blood into right ventricle and pulmonary circuit
  239. 239. © 2012 Pearson Education, Inc. Figure 21-35 Congenital Heart Problems Ventricular Septal Defect Ventricular septal defects are openings in the inter- ventricular septum that separate the right and left ven- tricles. These defects are the most common congenital heart problems, affecting 0.12 percent of newborns. The opening between the two ventricles has an effect simi- lar to a connection between the atria: When the more powerful left ventricle beats, it ejects blood into the right ventricle and pulmonary circuit. Ventricular septal defect Ventricular septum
  240. 240. © 2012 Pearson Education, Inc. 21-8 Fetal and Maternal Circulation • Atrioventricular Septal Defect • Both the atria and ventricles are incompletely separated • Results are quite variable, depending on extent of defect and effects on atrioventricular valves • This type of defect most commonly affects infants with Down’s syndrome, a disorder caused by the presence of an extra copy of chromosome 21
  241. 241. © 2012 Pearson Education, Inc. Figure 21-35 Congenital Heart Problems In an atriovenricular septal defect, both the atria and ventricles are incompletely separated. The results are quite variable, depending on the extent of the defect and the effects on the atrioventricular valves. This type of defect most commonly affects infants with Down’s syndrome, a disorder caused by the presence of an extra copy of chromosome 21. Atrioventricular Septal Defect Atrial defect Ventricular defect
  242. 242. © 2012 Pearson Education, Inc. 21-8 Fetal and Maternal Circulation • Transposition of Great Vessels • The aorta is connected to right ventricle instead of to left ventricle • The pulmonary artery is connected to left ventricle instead of right ventricle • This malformation affects 0.05 percent of newborn infants
  243. 243. © 2012 Pearson Education, Inc. Figure 21-35 Congenital Heart Problems In the transposition of great vessels, the aorta is connected to the right ventricle instead of to the left ventricle, and the pulmonary artery is connected to the left ventricle instead of the right ventricle. This malformation affects 0.05 percent of newborn infants. Transposition of the Great Vessels Patent ductus arteriosus Aorta Pulmonary trunk
  244. 244. © 2012 Pearson Education, Inc. 21-9 Effects of Aging and the Cardiovascular System • Cardiovascular Capabilities Decline with Age • Age-related changes occur in: • Blood • Heart • Blood vessels
  245. 245. © 2012 Pearson Education, Inc. 21-9 Effects of Aging and the Cardiovascular System • Three Age-Related Changes in Blood 1. Decreased hematocrit 2. Peripheral blockage by blood clot (thrombus) 3. Pooling of blood in legs • Due to venous valve deterioration
  246. 246. © 2012 Pearson Education, Inc. 21-9 Effects of Aging and the Cardiovascular System • Five Age-Related Changes in the Heart 1. Reduced maximum cardiac output 2. Changes in nodal and conducting cells 3. Reduced elasticity of cardiac (fibrous) skeleton 4. Progressive atherosclerosis 5. Replacement of damaged cardiac muscle cells by scar tissue
  247. 247. © 2012 Pearson Education, Inc. 21-9 Effects of Aging and the Cardiovascular System • Three Age-Related Changes in Blood Vessels 1. Arteries become less elastic • Pressure change can cause aneurysm 2. Calcium deposits on vessel walls • Can cause stroke or infarction 3. Thrombi can form • At atherosclerotic plaques
  248. 248. © 2012 Pearson Education, Inc. 21-9 Cardiovascular System Integration • Many Categories of Cardiovascular Disorders • Disorders may: • Affect all cells and systems • Be structural or functional • Result from disease or trauma
  249. 249. © 2012 Pearson Education, Inc. Figure 21-36 System Integrator: The Cardiovascular System S Y S T E M I N T E G R A T O R Body System Cardiovascular System Body SystemCardiovascular System IntegumentarySkeletalMuscularNervousEndocrine IntegumentarySkeletalMuscularNervousEndocrine Page165Page275Page369Page543Page632 The section on vessel distribution demonstrated the extent of the anatomical connections between the cardiovascular system and other organ systems. This figure summarizes some of the physiological relationships involved. The most extensive communication occurs between the cardiovascular and lymphatic systems. Not only are the two systems physically interconnected, but cells of the lymphatic system also move from one part of the body to another within the vessels of the cardiovascular system. We examine the lymphatic system in detail, including its role in the immune response, in the next chapter. The CARDIOVASCULAR System Stimulation of mast cells produces localized changes in blood flow and capillary permeability Provides calcium needed for normal cardiac muscle contraction; protects blood cells developing in red bone marrow Skeletal muscle contractions assist in moving blood through veins; protects superficial blood vessels, especially in neck and limbs Controls patterns of circulation in peripheral tissues; modifies heart rate and regulates blood pressure; releases ADH Erythropoietin regulates production of RBCs; several hormones elevate blood pressure; epinephrine stimulates cardiac muscle, elevating heart rate and contractile force Distributes hormones throughout the body; heart secretes ANP and BNP Endothelial cells maintain blood—brain barrier; helps generate CSF Delivers oxygen and nutrients, removes carbon dioxide, lactic acid, and heat during skeletal muscle activity Transports calcium and phosphate for bone deposition; delivers EPO to red bone marrow, parathyroid hormone, and calcitonin to osteoblasts and osteoclasts Delivers immune system cells to injury sites; clotting response seals breaks in skin surface; carries away toxins from sites of infection; provides heat Lymphatic Page807 Respiratory Page857 Digestive Page910 Urinary Page992 Reproductive Page1072
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