2. Introduction
The circulatory system or
cardiovascular system consists of
heart, blood , and blood vessels
Sends blood to
Lungs for oxygen
Digestive system for nutrients
Circulatory system also circulates
waste products to certain organ
systems for removal from the blood
3. THE FUNCTIONS OF THE SYSTEM
These are three functions:
Protection-the blood carries antibodies
which the body needs to fight an infection
Transportation- take things to the muscle
and take things away from the muscle. The
blood carries essentials like oxygen and
nutrients to the muscles and the blood
carries away carbon dioxide and other
waste
Temperature control-the blood transfers
heat around the body
4. The Heart: Location and Size
Approximately the size
of a person’s fist, the
hollow, cone-shaped
heart weighs less than
a pounds.
It is enclosed within the
inferior mediastinum,
the medial cavity of
the thorax, the heart is
flanked on each side of
lungs.
5. The Heart: Location and Size
It is more pointed
in the apex
because it is
directed toward
the left hip and
rests on the
diaphragm.
Its broad
posterosuperior
aspect, or base, from
which the great
vessels of the body
emerge, points
toward the right
shoulder and lies
beneath the second
rib.
6. The Heart: Covering and Wall
The heart is enclosed
by a doubled-walled
sac called
pericardium.
The loosely fitting
superficial part of this
sac is referred to as to
as the fibrous
pericardium. It helps
protect the heart and
anchors it to
surrounding structures,
such as the diaphragm
and sternum.
7. Deep to the fibrous pericardium is the slippery, two
layer serous pericardium.
Its parietal layer lines the interior of the fibrous
pericardium. At the superior aspect of the heart, this
parietal layer attaches to the large arteries leaving
the heart and then makes a U- turn and continues
inferiorly over the heart surface as the visceral layer
or epicardium, which is actually the part of the heart
wall.
The Heart: Covering and Wall
8. A slippery lubricating fluid (serous
fluid) is produced by the serous
pericardial membranes. This fluid
allows the heart to beat easily in a
relatively frictionless environment
as the serous pericardial layers
slides smoothly across each other.
The Heart: Covering and Wall
9.
10. The Heart: Covering and Wall
The heart walls
are composed
of three layers:
The outer
epicardium , the
myocardium,
and the
innermost
endocardium.
The myocardium
consists of thick bundles
of cardiac muscle
twisted and whorled
into ringlike
arrangements.
The endocardium is a
thin, glistening sheet of
endothelium that lines
the heart chambers.
11.
12. Chambers of Heart
The heart has
four
chambers
namely:
Two Atria
Two
Ventricle
Four chambers
Two atria
Upper chambers
Left and right
Separated by interatrial
septum
Two ventricles
Lower chambers
Left and right
Separated by
interventricular septum
Atrioventricular septum separates the atria
from the ventricles.
13. Chambers of Heart
The septum that divides the heart
longitudinally is referred to as either
the interventricular septum or the
interatrial septum, depending on
which chamber it separates.
14. Valves
Atrioventricular Valve
Tricuspid valve –
prevents blood from
flowing back into the
right atrium when the
right ventricle
contracts
Bicuspid valve –
prevents blood from
flowing back into the
left atrium when the
left ventricle
contracts
Semilunar Valves
Pulmonary valve –
prevents blood from
flowing back into the
right ventricle
Aortic valve –
prevents blood from
flowing back
into the left ventricle
15.
16.
17. The Heart: Blood Flow
Deoxygenated
blood in from
body
Oxygenated
blood in lungs
Atria Contract Ventricles Contract
Deoxygenated
blood out
to lungs
Oxygenated
blood out to
body
18. The Heart: Blood Flow (cont.)
Right
Atrium
Right
Ventricle
Pulmonary
Semilunar
Valve
Left
Atrium
Bicuspid
Valve
Left
Ventricle
Pulmonary
Valve
Tricuspid
Valve
Aortic
Semilunar
Valve
LungsBody
19. The Heart: Cardiac Conduction System
Group of structures that send electrical impulses through the
heart
Sinoatrial node (SA node)
Wall of right atrium
Generates impulse
Natural pacemaker
Sends impulse to AV node
Atrioventricular node (AV
node)
Between atria just above ventricles
Atria contract
Sends impulse to the bundle of His
Bundle of His
Between ventricles
Two branches
Sends impulse to Purkinje
fibers
Purkinje fibers
Lateral walls of ventricles
Ventricles contract
20.
21. The Heart: Cardiac Cycle
Right atrium contracts
Tricuspid valve opens
Blood fills right ventricle
Right ventricle contracts
Tricuspid valve closes
Pulmonary semilunar valve
opens
Blood flows into pulmonary
artery
Left atrium contracts
Bicuspid valve opens
Blood fills left ventricle
Left ventricle contracts
Bicuspid valve closes
Aortic semilunar valve
opens
Blood pushed into aorta
One heartbeat = one cardiac cycle
Atria contract and relax
Ventricles contract and relax
22. The Heart: Heart Sounds
One cardiac cycle – two heart
sounds (lubb and dubb) when
valves in the heart snap shut
Lubb – First sound
When the ventricles contract, the
tricuspid and bicuspid valves snap
shut
Dubb – Second sound
When the atria contract and the
pulmonary and aortic valves snap shut
24. Physiology of Circulation
Vital signs
the signs that indicate
life, example: pulse,
body temperature,
breathing, and blood
pressure.
Body Sites of Arterial
Pulse
1. Temporal Artery
2. Facial artery
3. Common Carotid
Artery
4. Brachial Artery
5. Radial Artery
6. Femoral Artery
7. Popliteal artery
8. Posterior Tibial Artery
9. Dorsalis Pedis Artery
Pulse - the regular expansion
and contraction of an
artery, caused by the heart
pumping blood through the
body.
25. Apply Your Knowledge
Match the following:
1. __ Tricuspid valve A. Two branches; sends impulse
to Purkinje fibers
2. __ Bicuspid valve B. Covering of the heart and
aorta
3. __ Pericardium C. Between the right atrium and the right
ventricle
4. __ SA node D. In the lateral walls of ventricles
5. __ Bundle of His E. Natural pacemaker
6. __ Purkinje fibers F. Between the left atrium and
the left ventricle
C
F
B
E
A
D
26. Blood
Blood, vital fluid found
in humans and other
animals that provides
important nourishment
to all body organs
and tissues and carries
away waste materials.
Sometimes referred to
as “the river of life,”
blood is pumped from
the heart through a
network of blood
vessels collectively
known as the
circulatory system.
Average-sized adult
has 4 to 6 liters of
blood
Amount depends on:
Size of person
Amount of adipose
(fatty tissues) tissue
Concentrations of
ions
Females have less
than males
27. COMPOSITION OF BLOOD
About 55 percent of the
blood is composed of a
liquid known as plasma.
The rest of the blood is
made of three major
types of cells: red blood
cells (also known as
erythrocytes), white
blood cells (leukocytes),
and platelets
(thrombocytes).
28. Blood: Bleeding Control
Hemostasis – the
control of bleeding
Three processes of
hemostasis
Blood vessel spasm
Platelet plug formation
Blood coagulation
29. Blood Vessels
Arteries carry oxygen-rich
blood from the heart,
branching to smaller and
smaller units ending at the
cpillaries.
Capillaries which transfer
oxygen and other blood
components to and from
the tissues. Oxygen-poor
blood continues through
the capillaries to veins.
Veins which
converge to carry
blood back to the
heart, lungs, and
liver.
Blood Vessel, any of the veins, arteries, and
capillaries that transport blood through the body.
30.
31. Blood Vessels: Microscopic Anatomy
The covering or coat of the blood vessels
is called tunics.
Three Parts of tunics:
Tunica intima- its cells fit closely together and
form a slick surface that decreases friction as
blood flows through the vessel lumen.
Tunica media- bulky middle coat. Sheets of
elastic tissues
Tunica externa- composed of fibrous
connective tissue having a function of support
and protect the vessels.
32. Arteries: Major Parts
Aorta is the largest artery in the body.
for the adult, the size of the aorta is about the
size of a garden hose having a diameter of your
thumb.
Parts of Aorta
Ascending aorta
Aortic arch
Abdominal aorta
33. Capillaries
Capillary, one of the minute blood vessels that form
the connection between the arteries and the veins.
These tiny vessels vary in diameter from 0.0127 to about
0.2032 mm (0.0005 to about 0.008 in) and are present
in great numbers throughout the entire body. The walls
of capillaries are exceedingly thin and readily
permeable. They are surrounded by lymph, and there
is a constant interchange between the substances in
the blood within the capillaries and the waste products
in the body tissues and lymph outside. This interchange
facilitates the processes of nutrition and elimination
and enables the exchange of oxygen and carbon
dioxide to take place.
Lymph capillaries assist the blood capillaries in this
process.
34. Veins: Major Parts
Parts of Veins
Superior Vena
Cava- draining
the head and
arms empty.
Inferior Vena
Cava- draining
the lower body
empty.
35. Apply Your Knowledge
How do arteries control blood pressure?
ANSWER: The muscular walls of arteries can constrict to
increase blood pressure or dilate to decrease blood
pressure.
36. Blood Pressure
Is the pressure that
exerts against the
inner walls of the
blood vessel, and
it is a force that
keeps blood
circulating
continuously even
between
heartbeats.
38. Blood Pressure
Diastolic - It is the pressure that is exerted on the
walls of the various arteries around the body in
between heart beats when the heart is relaxed.
Normal range -60 – 80 mmHg (adults); 65 mmHg
(infants); 65 mmHg (6 to 9 years)
Importance with age - Diastolic readings are
particularly important in monitoring blood pressure
in younger individuals.
Blood Pressure - Diastolic represents the minimum
pressure in the arteries.
Ventricles of the heart - Fill with blood
Blood Vessels - Relaxed
39. Blood Pressure
Systolic - It measures the amount of pressure that
blood exerts on arteries and vessels while the
heart is beating.
Normal range - 90 – 120 mmHg (adults); 95 mmHg
(infants); 100 mmHg (6 to 9 years)
Importance with age - As a person's age
increases, so does the importance of their systolic
blood pressure measurement.
Blood Pressure -Systolic represents the maximum
pressure exerted on the arteries.
Ventricles of the heart - Left ventricles contract
Blood Vessels - Contracted
40. Apply Your Knowledge
What is the difference between the systolic pressure
and diastolic pressure?
ANSWER: Systolic pressure is the result of the
contraction of the ventricles increasing the pressure in
the arteries. Diastolic pressure is the result of the
relaxation of the ventricles lowering the pressure in the
arteries.
GoodAnswer!
41. Apply Your Knowledge
ARTERIES: Pulmonary arteries carry oxygen-poor blood.
Do pulmonary arteries carry blood with high levels of
oxygen or low levels of oxygen?
43. Diseases and Disorders of the
Cardiovascular System
Disease Description
Anemia The blood does not have enough red blood cells
or hemoglobin to carry an adequate amount of
oxygen to the body’s cells
Aneurysm A ballooned, weakened arterial wall
Arrhythmias Abnormal heart rhythms
Carditis Inflammation of the heart
Endocarditis Inflammation of the innermost lining of the
heart, including valves
44. Diseases and Disorders of the
Cardiovascular System (cont.)
Disease Description
Myocarditis Inflammation of the muscular layer of the heart
Pericarditis Inflammation of the membranes that surround
the heart (pericardium)
Congestive
Heart Failure
Weakening of the heart over time; heart is
unable to pump enough blood to meet body’s
needs
Coronary
Artery Disease
(CAD)
Atherosclerosis; narrowing of coronary arteries
caused by hardening of the fatty plaque deposits
within the arteries
45. Diseases and Disorders of the
Cardiovascular System (cont.)
Disease Description
Hypertension High blood pressure; consistent resting blood
pressure equal to or greater than 140/90 mm Hg
Leukemia Bone marrow produces a large number of
abnormal WBCs
Murmurs Abnormal heart sounds
Myocardial
Infarction
Heart attack; damage to cardiac muscle due to a
lack of blood supply
46. Diseases and Disorders of the
Cardiovascular System (cont.)
Disease Description
Sickle Cell
Anemia
Abnormal hemoglobin causes RBCs to change
to a sickle shape; abnormal cells stick in
capillaries
Thalassemia Inherited form of anemia; defective
hemoglobin chain causes, small, pale, and
short-lived RBCs
Thrombophlebitis Blood clots and inflammation develops in a
vein
Varicose Veins Twisted, dilated veins
47. Apply Your Knowledge
ANSWER: Anemia is a condition in which a person does not
have enough red blood cells or hemoglobin in the blood to
carry an adequate amount of oxygen to body cells.
The doctor has told your patient she has anemia. How
would you explain this to the her?
Bravo!