The cardiovascular system consists of the heart and blood vessels, and works to circulate blood throughout the body. The heart is located in the chest cavity and has four chambers - the right and left atria receive blood, while the right and left ventricles pump it out. Blood vessels include arteries, which carry blood away from the heart, veins which carry blood back to it, and capillaries where nutrient exchange occurs. Together, the cardiovascular system transports oxygen, nutrients, hormones and removes carbon dioxide and wastes to help regulate functions throughout the body.

1. CARDIOVASCULAR
SYSTEM

2. CONTENTS
Meaning
Introduction
Heart
Blood vessels
Function of cardiovascular system
Points to be noted
MCQS

3. MEANING
 Cardiovascular system is made up of two words ; cardiovascular and
system where ,
CARDIOVASCULAR : relating to the circulatory system ,
which comprises the heart and blood vessels
and carries nutrients and oxygen to the tissues
and removes carbondioxide and other wastes from
body
SYSTEM : group of interlacting or interrelated entities
that form a unified or group of organs that
work together to carry out a particular task

4. INTRODUCTION
Also known as circulatory system
Is transport system carrying oxygen , nutrients ,
hormones and other substances to the tissue and
conveying carbondioxide to the lungs and other waste
products to the kidneys
Consists of cardiac ( heart ) and vascular ( blood vessels
)

5. HEART
 A hollow muscular organ which acts as a
compression pump
 Is pyramidal in shape and the size of your
fist
 Situated in middle mediastinum in between
the two lungs
 The 2/3rd part of heart lie towards the left
side of the body and remaining 1/3rd part of
heart lies towards right side of body
 Weighs about 300gm in male and 250gm
in female

6. COVERINGS OF THE HEART
 Heart is composed by a fibro serous sac called
pericardium . It has two layers ;
Fibrous pericardium :
- an outer membrane made up of strong
fibrous sheath
- is conical in shape
- connected to sternum anteriorly ,
diaphragm inferiorly and roots of great
blood vessels superiorly
- helps to maintain shape of the heart

7. Contd…
Serous pericardium :
- an inner layer , made up of serous membrane
- has two layers ; parietal and visceral layer
- parietal layer lies just inside the fibrous
pericardium
- visceral layer is closely related to the surface of
the heart
- pericardial cavity is a cavity between the parietal
and visceral layers of the serous pericardium
- pericardial cavity is filled with a fluid called
pericardial fluid

8. LAYERS OF HEART
 The heart wall consists of three layers ;
1. Epicardium :
- outermost layer formed by visceral
layer of serous pericardium
2. Myocardium :
- middle layer composed of
specialized muscular layer known
as cardiac muscle
- involuntary muscle controlled by
autonomic nervous system
- gets the blood supply from the right
and left coronary arteries

9. Contd…
3. Endocardium :
- innermost layer consisting of a
single layer of epithelial cells known
as epithelium
- provides a smooth lining for the
blood to flow over
- is continuous with the valves of the
heart and blood vessels

10. FEATURES OF THE HEART
 Heart consists of following parts
 Chambers :
- Right atrium - Left atrium
- Right ventricle - Left ventricle
 Valves :
- Right atrioventricular valve (Tricuspid valve)
- Left atrioventricular valve (Bicuspid or Mitral
valve)
- Semilunar valve (Aortic and Pulmonic valve)

11. Contd…
 Septum :
- Interatrial septum
- Interventricular septum
 Grooves and sulci :
- Atriventricular groove
- Interventricular groove
a. anterior
b. posterior

12. CHAMBERS OF THE HEART
Right atrium :
 Situated on the right part of the heart
 Receives deoxygenated blood from whole of the
body via the superior venacava at its upper end
and inferior venacava at its lower end
 Pumps blood to right ventricle through tricuspid
valve

13. Contd…
Right ventricle :
 A crescent shaped chamber situated on right side
of the heart below right atrium
 Pumps received blood into lungs for oxygenation
through pulmonary artery

14. Contd…
Left atrium :
 Situated behind the right atrium
 Forms base of the heart
 Receives oxygenated blood from lungs through
pulmonary veins
 Pumps blood into left ventricle through mitral valve

15. Contd…
Left ventricle :
 Nearly a circular chamber
 Blunt tips forms apex of the heart
 Pumps oxygenated blood through out the body
via aorta
 The wall is three times thicker as compared to
right ventricle in order to pump blood to whole
body

16. VALVES OF THE HEART
Tricuspid valve :
 Is atrioventricular valve
 Present between right atrium and right
ventricle
 Has three leaflets : anterior , septal and
posterior

17. Contd…
Mitral valve :
 Also known as bicuspid valve
 Is atrioventricular valve
 Present between left atrium and left
ventricle
 Has two leaflets : anterior and posterior

18. Contd…
Pulmonary valve :
 Is semilunar valve
 Present between right ventricle and
pulmonary artery
 Has three flaps

19. Contd…
Aortic valve :
 Is semilunar valve
 Present between left ventricle and
aorta
 Has three flaps

20. SEPTUM OF THE HEART
Interatrial septum :
- divides right atrium and left atrium
Interventricular septum :
- divides right and left ventricles

21. GROOVES AND SULCI OF THE
HEART
Atriventricular groove :
- a small circular depression on the
surface of the heart which
separates atrium and ventricles
Interventricular groove :
- separates the two ventricles on the
surface of heart
- has anterior and posterior parts

22. CONDUCTING SYSTEM OF THE
HEART
 Is the specialized myocardium that initiate and
conduct impulses for the contraction of the
heart
 Consists of following parts ;
1. Sinoatrial node or SA node
2. Artioventricular node or AV node
3. Artioventricular bundle or AV bundle
or bundle of HIS
4. The right bundle branch
5. The left bundle branch
6. The purkinje fibers

23. Contd…
Sinoatrial node or SA node :
- mass of specialized type of cells
- situated in wall of right atrium
near the opening of superior
venacava
- also known as “pacemaker”
- generates an impulse and
initiates the heart beat

24. Contd…
Atrioventricular node or AV node :
- situated in the lower and dorsal part
of atrial septum
- receives impulses generated by SA
node through atrial wall

25. Contd…
Artioventricular bundle or AV
bundle or bundle of HIS :
- the only muscular connection
between atrial and ventricular
musculatures
- begins as atrioventricular node ,
crosses AV ring and descends to
ventricular septum
- divides into right and left branches
at the upper border of muscular part
of septum

26. Contd…
The right bundle branch :
- passes down the right side of
the interventricular septum
- reaches wall of right ventricles
after dividing into purkinje fibers
The left bundle branch :
- goes to the left side of
interventricular septum
- distributes to left ventricle after
dividing into purkinje fibers

27. Contd…
Purkinje fibers :
- thin fibers of myocardium
- made from right and left bundle
branches which are distributed to
the wall of ventricle

28. ORGAN ASSOCIATED WITH THE
HEART
 Superiorly : the great blood vessels i.e the aorta ,
superior venacava , pulmonary artery and
pulmonary veins
 Inferiorly : the apex rests on the central tendon of the
diaphragm
 Anteriorly : the sternum , ribs and intercostal muscle
 Posteriorly : the oesophagus , trachea , left and right
bronchi , descending aorta , inferior
venacava and thoracic vertebrae
 Laterally : the lungs – the left lung overlaps the side of
the heart

29. BLOOD SUPPLY OF THE HEART
 Heart receives its blood supply from :
a. Right coronary artery :
- aries from the ascending aorta
- larger than left coronary artery
- supplies blood to the right part of
heart including right atrium , right
ventricle , SA node , AV node and
some portion of the posterior part
of left ventricle

30. Contd…
b. Left coronary artery :
- arises from the ascending
aorta
- supplies blood to left part of
heart such as left atrium , left
ventricle and some part of
anterior portion of right
ventricle
 The deoxygenated blood from heart
goes to right atrium through coronary
sinus .

31. NERVE SUPPLY OF THE HEART
 Is supplied by sympathetic and parasympathetic
component of autonomic nervous system
 Sympathetic nerves increases heart rate and
parasympathetic nerve decreases heart rate

32. BLOOD VESSELS
 Component of circulatory system which carries
blood
 There are three types of blood vessels in human
body according to anatomy ;
1. Artery
2. Veins
3. Capillary

33. Artery
 Blood vessels that transport blood away from
heart
 Carries pure blood except pulmonary artery
 The wall of arteries consists of 3 layers from
outside inwards . They are :
i. Tunica adventitia (made up of
connective tissue)
ii. Tunica media (made up of smooth
muscle)
iii. Tunica intima ( made up of
endothelium)

34. Contd…
 Arterial branches becomes narrower and
their walls become thinner while
reaching periphery called arterioles
 Arterioles are continued as capillaries
 Capillaries are very small vessels in which
exchange of gases and materials takes
place

35. Veins
 Blood vessels that transport blood to heart
 Carries deoxygenated blood except pulmonary
vein
 Venules unite and forms veins
 Different veins of the body unite and forms
venacava

36. Contd…
 There are two venacava in human body :
1. Superior venacava :
- carries blood from upper part of
body including head , neck and
upper limbs
2. Inferior venacava :
- carries blood from lower part of
body including thorax , abdomen,
pelvis and lower limbs

37. Capillaries
 Are the minute vessels from smallest
arteriole
 Consists of a single layer of endothelial
cells , through which water and other
small molecular substance can pass
 Form a vast network of tiny vessels thus
bring the nutritional materials and
oxygen to the cells

38. FUNCTIONS OF CARDIOVASCULAR
SYSTEM
 Circulates oxygen and removes carbondioxide
 Provides cell with the nutrients
 Removes waste products of metabolism to the excretory
organs for disposal
 Helps regulate body temperature
 Protects the body from infection and blood loss

39. POINTS TO BE NOTED
 Cardiovascular system is also known as circulatory system .
 It is a transport system .
 It consists of cardio (heart) and vascular (blood vessels) .
 Heart is a size of your own fist .
 Heart weighs 300 gm in male and 250 gm in female .
 Heart is covered by a fibro serous sac called pericardium .

40. Contd…
 Pericardial cavity is a cavity between parietal and visceral
layer which consists of pericardial fluid .
 Heart has four chambers ; right atrium , right ventricle , left
atrium and left ventricle .
 Atrioventricular valves are tricuspid valve and mitral valve .
 Mitral valve is also known as bicuspid valve .
 Semilunar valves are pulmonary valve and aortic valve .

41. Contd…
 Heart is supplied with blood by right and left coronary
artery .
 Sinoatrial node is also known as pacemaker .
 Arteries consists of 3 layers from outside inwards ; tunica
adventitia , tunica media and tunica intima .
 Capillaries are very small vessels in which exchange of gases
and materials takes place .

42. MCQS
1. Circulatory system is a
a. ventilatory system b. transport system
c. excretory system d. none of the above
2. The cavity between parietal layer and visceral layer of heart is called
a. pericardial cavity b. pleural cavity
c. parietal cavity d. none of the above
3. The innermost layer of blood vessel is
a. tunica adventitia b. tunica media
c. tunica intima d. none of the above

43. 4. The heart is supplied by
a. coelic artery b. intercostal artery
c. right and left coronary arteries d. mesenteric arteries
5. The wall of left ventricle is ……….. right ventricle .
a. equal in thickness to b. thinner than
c. thicker than d. none of the above
6. ………. is also known as pacemaker of the heart .
a. sinoatrial node b. atrioventricular node
c. bundle of HIS d. purkinje fibers
7. Largest vein of the body
a. superior venacava b. inferior venacava
c. pulmonary veins d. aorta

44. 8. Largest artery of the body
a. pulmonary artery b. renal artery
c. aorta d. carotid artey
9. Backflow of blood is prevented by
a. valves b. ventricles
c. atrium d. none of the above
10. Valve that is present between right ventricle and lungs is
a. tricuspid valve b. aortic valve
c. bicuspid valve d. pulmonic valve
ANSWERS
1. B 2 . A 3 . C 4 . C 5 . C
6. A 7 . B 8 . C 9 . A 10 . D