The cardiovascular system consists of the heart and blood vessels. The heart is a muscular pump located in the chest cavity that pumps blood through two circuits - the pulmonary circulation and the systemic circulation. It has four chambers - two upper atria and two lower ventricles. The right side pumps deoxygenated blood to the lungs and the left side pumps oxygenated blood to the body. Important structures include the valves that ensure one-way blood flow and the specialized conduction system that coordinates heart contractions. The heart is supplied with oxygenated blood from the coronary arteries on its surface.

1. Cardio Vascular System
Mr. Ramar G
Professor
Hind College of Nursing
Lucknow.

2. Introduction
• A closed system of the heart and blood vessels
• The cardio vascular system is divided for
descriptive purposes into two.
– The Circulatory System: consists of heart & blood
vessels
– The Lymphatic System: consists of lymph nodes &
Lymph vessels
– The function of the cardiovascular system is to deliver
oxygen and nutrients and to remove carbon dioxide
and other waste products

3. The Heart

4. Overview
• The right side receives
oxygen-poor blood from the
body and tissues and then
pumps it to the lungs to pick
up oxygen and dispel carbon
dioxide
• Its left side receives
oxygenated blood returning
from the lungs and pumps this
blood throughout the body to
supply oxygen and nutrients
to the body tissues
The heart=a muscular double pump with 2 functions

5. The Heart
• The heart is a conical hollow muscular
organ situated in the middle mediastinum.
• It is enclosed within the pericardium
• It pumps blood to the various parts of the
body.
• The Greek name for the heart is cardia &
the Latin name is coronary

6. Heart : Measurements
• Heart measures 12x9cm and is about the size
of the owner’s fist.
• It weighs about 300 g in males and 250 g in
females

7. Facts, Location, & Orientation
• Heart lies in the thoracic cavity in the
mediastinum between the lungs, lies Obliquely, a
little more to the left than right.
• It presents a base above and an apex below.
• Apex is about 9cm to the left of the midline
&points inferiosinister (down and left) , little
below to nipple and slightly nearer to the midline
–5th intercostal space,

8. Contd…….
• Base is superior near origins of great vessels
– 2nd intercostal space
• 2/3 lies left of the midline
• For the most part
– Anterior/inferior aspect of the heart
• right atrium/ventricle
– Posterior/superior aspect
• left atrium/ventricle
• Heart pumps over 1 million gallons per year
• Over 60,000 miles of blood vessels

9. Heart’s position in thorax
9

10. Organs associated
• Inferiorly: the apex rests on the central tendon of
the diaphragm
• Superiorly: the great blood vessels
• Posteriorly: the esophagus, trachea, left and right
bronchus, descending aorta, inferior vena cava
and thoracic vertebrae.
• Laterally: lungs
• Anteriorly: the sternum, ribs and inter costal
muscles

11. Location & Associations
Figure 18.1

12. 12

13. Break

14. Structure
• Heart is composed of three layers of tissue
1. Pericardium
2. Myocardium
3. Endocardium

15. Pericardium
• Pericardium is made of two sacs. The outer sac consists
of fibrous tissue and the inner is of a continuous double
layer of serous membrane.
• Fibrous pericardium
– dense irregular CT
– protects and anchors the heart, prevents
overstretching
• Serous pericardium
– thin delicate membrane contains
• parietal layer-outer layer
• pericardial cavity with pericardial fluid
• visceral layer (epicardium)

16. Pericardium

17. Myocardium
• It is composed of specialized
cardiac muscle found only in
the heart.
• It is under involuntary
control.
• Cross stripes are seen in
microscopic examination.
• Myocardium is thickest at
the apex and thins out
towards base. It is thickest in
the left ventricle.

18. Endocardium
• This forms the lining of the myocardium and
heart valves.
• It is a thin , smooth, glistening membrane
which permits the smooth flow of blood inside
the heart.
• It consists of flattened epithelium that lines
the blood vessels.

19. Surface anatomy
• Sulci - grooves on
surface of heart
containing coronary
blood vessels and fat
– coronary sulcus
• encircles heart and
marks the boundary
between the atria and the
ventricles
– anterior interventricular
sulcus
• marks the boundary
between the ventricles
anteriorly

20. Posterior view

21. Break

22. Interior To Heart

23. Chambers of the heart
sides are labeled in reference to the patient facing you
• Two atria
– Right atrium
– Left atrium
• Two ventricles
– Right ventricle
– Left ventricle
23
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24. Right Atrium
• Receives blood from 3
sources
– superior vena cava, inferior
vena cava and coronary
sinus
• Interatrial septum partitions
the atria
• Fossa ovalis is a remnant of
the fetal foramen ovale
• Tricuspid valve
– Blood flows through into
right ventricle
– has three cusps composed
of dense CT covered by
endocardium
20-24
Right Ventricle
• Forms most of anterior surface of
heart
• Papillary muscles are cone
shaped trabeculae carneae
(raised bundles of cardiac
muscle)
• Chordae tendineae: cords
between valve cusps and
papillary muscles
• Interventricular septum:
partitions ventricles
• Pulmonary semilunar valve:
blood flows into pulmonary trunk

25. Left Atrium
• Forms most of the base of the heart
• Receives blood from lungs - 4 pulmonary
veins (2 right + 2 left)
• Bicuspid valve: blood passes through
into left ventricle
– has two cusps
– to remember names of this valve, try
the pneumonic LAMB
• Left Atrioventricular, Mitral, or
Bicuspid valve
20-25
Left Ventricle
• Forms the apex of heart
• Chordae tendineae anchor
bicuspid valve to papillary
muscles (also has trabeculae
carneae like right ventricle)
• Aortic semilunar valve:
– blood passes through valve
into the ascending aorta
– just above valve are the
openings to the coronary
arteries

28. Valves
three tricuspid
one bicuspid
• “Tricuspid” valve
– RA to RV
• Pulmonary or pulmonic valve
– RV to pulmonary trunk (branches R and L)
• Mitral valve (the bicuspid one)
– LA to LV
• Aortic valve
– LV to aorta
28
(cusp means flap)

29. 29
Function of AV valves

30. 30
Function of semilunar valves
(Aortic and pulmonic valves)

31. Valves
• A-V valves open and allow blood to flow
from atria into ventricles when
ventricular pressure is lower than atrial
pressure
– occurs when ventricles are relaxed,
chordae tendineae are slack and
papillary muscles are relaxed
• A-V valves close preventing backflow of
blood into atria
– occurs when ventricles contract, pushing valve
cusps closed, chordae tendinae are pulled taut and
papillary muscles contract to pull cords and prevent
cusps from everting
20-31
• Semilunar valves open with
ventricular contraction
– allow blood to flow
into pulmonary trunk
and aorta
• SL valves close with
ventricular relaxation
– prevents blood from
returning to ventricles,
blood fills valve cusps,
tightly closing the SL
valves

32. Semilunar Valve
(pulmonary)
20-32
Chordae tendinae
Papillary
muscle
Interatrial septum
Right atrium
Tricuspid AV valve
Semilunar Valve
(aortic)

33. Break

34. Blood Supply

35. Right coronary blood supply
• Right coronary artery
– Originates from ostia in right aortic sinus
• Superior to right aortic cusp
– Travels in right coronary (AV) sulcus
– Branches
• Right marginal arteries (acute marginal aa)
• Posterior interventricular a. (in post. IV sulcus)
• Sinoatrial nodal a.
• Atrioventricular nodal a.

37. Left coronary blood supply
• Left coronary artery
– Originates from ostia in left aortic sinus
• Superior to left aortic cusp
– Branches
• Left anterior descending (LAD) or anterior
interventricular a. (lies in anterior IV sulcus)
– Septal branches.
– Diagonal branches
• Left marginal aa. (Obtuse marginal aa.)
• Left circumflex a.

39. Venous drainage of the heart
• Coronary sinus
– Lies in coronary (AV) sulcus on posterior
– Opens directly to right atrium
– All venous drainage of the heart eventually flows here
• Great cardiac vein
– With LAD in anterior IV sulcus
• Left marginal vein
• Middle cardiac vein
– With posterior interventricular a.
• Small cardiac vein
– With right coronary a.
• Right marginal vein
• Oblique vein (LA)
• Posterior vein of the left ventricle

41. Blood Circulation
• Systemic circulation
– left side of heart pumps blood through body
– left ventricle pumps oxygenated blood into aorta
– aorta branches into many arteries that travel to organs
– arteries branch into many arterioles in tissue
– arterioles branch into thin-walled capillaries for exchange of gases and
nutrients
– deoxygenated blood begins its return in venules
– venules merge into veins and return to right atrium
20-41
• Pulmonary circulation
– right side of heart pumps deoxygenated blood to lungs
– right ventricle pumps blood to pulmonary trunk
– pulmonary trunk branches into pulmonary arteries
– pulmonary arteries carry blood to lungs for exchange of gases
– oxygenated blood returns to heart in pulmonary veins

43. Blood Circulation
• Blood flow
– blue = deoxygenated
– red = oxygenated
20-43

44. 20-44
SVC/IVC Right Atrium (tricuspid valve) Right Ventricle
Lungs
Left Atrium
Pulmonary Arteries
Pulmonary Veins
Aorta Left Ventricle
(aortic semilunar valve)
Body
Body
bicuspid (mitral) valve
(pulmonary semilunar valve)
Passage of Blood through the Heart

45. 20-45
The
Heartbeat
each heartbeat = cardiac cycle
-SL valves close
“dup”
-AV valves open
-filling of atria &
ventricles begins
-contraction of ventricles
-AV valves close “lub”
-SL valves open
-blood to lungs and body
**Heart Murmur**
-contraction of
atria
-AV valves open
-filling of
ventricles =
“Ventricular
Filling stage”

46. Electrical conduction system:
46
(Explanation in next slides)
specialized cardiac muscle cells that carry
impulses throughout the heart musculature,
signaling the chambers to contract in the
proper sequence

47. Conduction system
• SA node (sinoatrial)
– In wall of RA
– Sets basic rate: 70-80
– Is the normal pacemaker
• Impulse from SA to atria
• Impulse also to AV node via internodal
pathway
• AV node
– In interatrial septum
47

48. Conduction continued
• SA node through AV bundle (bundle of His)
– Into interventricular septum
– Divides
R and L bundle branches
become subendocardial
branches (“Purkinje
fibers”)
• Contraction begins
at apex
48

49. 49

50. Thank You