CARDIOVASCULAR SYSTEM HAP 1ST YEAR

1. SUBHAM SOURAJIT
ASST PROFESSOR
DEPT OF PHARMACOLOGY

2.  SIZE-12cm long, 9cm wide, 6cm thick
 Weight- 250gm in female and 300gm in male
 Position- Superior surface of diaphragm, left of
midline, anterior to vertebral column & posterior
to sternum.

4. Heart has 4 chambers i.e. 2 upper or superior
chamber called as Atrium and 2 lower or inferior
chamber called as Ventricle.
Right Atrium- Receives impured blood from vein
from different parts of body.
Blood passes from right atrium to right
ventricle through tricuspid valves consist of 3
cups.
Right Ventricles- Blood passes from right ventricle
to lungs through pulmonary valve into the large
artery called pulmonary artery.

5. Left Atrium- Receives blood from lungs
through pulmonary vein.
Blood passes from left atrium to left
ventricle through Bicuspid Valve, consist of 2
cups, also known as Mitral Valve.
Left Ventricle- Blood passes from left ventricle
to aorta through aortic valve that carry blood
to whole the body parts.

6. Atrio-ventricular Valve- They are called as so,
located between atrium & ventricle i.e.,
tricuspid valve and bicuspid valve.
When AV valves opens the blood flows from
atrium to ventricle.
Semilunar Valve- Semilunar valve allows the
blood flow from the heart into arteries,
preventing the back flow of blood into
ventricles.

7. 1.PERICARDIUM- Outer Layer
2. MYOCARDIUM- Middle Layer
3. ENDOCARDIUM- Inner Layer

8.  Arteries- Carries blood away from heart.
 Arterioles- Branches of Artery
 Capillaries- Smallest blood vessel, location of
exchange between blood & mineral fluids.
 Venules- Collect blood from capillaries, Branch of
Vein
 Veins- Return blood to heart

9. Vessel wall have 3 layer.
a. Tunica Intima- Inner Layer
b. Tunica Media- Middle Layer
c. Tunica Exterma- Outer Layer

10. Tunica intima
 It is the Endothelial layer that lines the lumens of all
vessels.
 In vessels larger than 1 mm, a sub endothelial
connective tissue basement membrane is present.
Tunica Media
 Smooth muscle and electric fibre layer is present
which is regulated by Sympathetic Nervous System.
 It helps for Vaso-Constriction & Vaso-Dialation.
Tunica Exterma
 Collagen Fibre is present which protects the vessel.
 Larger Vessels contain Vasa-Vasorum.

11. Arteries & Arterioles have thicker wall then
vein & venules because they are closer to
heart and receive blood i.e., serving at a
far greater pressure

12.  The heart pumps blood through the body which
is accomplished by Contraction & Relaxation
of cardiac muscle tissue in myocardial layer.
 Intercalated Disc allow impulse to travel
rapidly between adjacent cells so they function
as one rather than individual cells.
Cont..

13.  The electrical conduction system that controls the
heart rate
 This system creates the electrical impulses and
sends them through out the heart. These impulses
make the heart contract & pump blood.
Cont..

14. SA NODE (Sino-Atrial Node)
 Located in the back wall of the right atrium near
the entrance of Vana-Cava.
 Initiates impulses 70-80 times per minute without
any stimulation from brain.
 At the same time impulses reach the second part of
the conduction system.
Cont..

15. AV NODE (Atrio- Ventricular Node)-
 Located in the bottom of right atrium near septum.
 Cells in the AV Node conduct impulses more
slowly so there will be a delay as impulses travel
through out the node, this allows time for atria to
finish contraction before ventricle begin
contracting.
Cont..

16. AV Bundle-
 From the AV Node impulses travels through right
and left bundle branches. These branches extend
to the right and left side of bundle branches extend
to the right & left side of the septum and bottom
of the heart i.e., called “Bundle of His”.
 These branches a lot to form Purkinje Fibres that
transmit the impulse to the Myocardium.
 Bundle of His & Purkinje Fibre transmit quickly
& cause both the ventricle to contract at the same
time.
 As the ventricle contract, blood is forced through
the Semi Lunar Valve into the Pulmonary Vein &
Aorta.

17.  A sequence of coordinated events taking place in heart
during each beat.
 All changes are repeated during each heart beat.
Stages
1. Arterial Systole-
 It is the contraction of artery.
 It takes 0.1 Sec.
 During this stage Van cava receives deoxygenated
blood in the right atrium & oxygenated blood in left
atrium.
 AV valve open and blood moves to ventricle.
Cont..

18.  The SA Node triggers a wave of contraction that
spread over the myocardium of both atria, emptying
atria & complete ventricular filling.
Ventricular Systole-
 It is contraction of ventricle
 It takes 0.1Sec.
 When AV Node triggers, it results a wave of
contraction & blood flow upward through pulmonary
artery & aorta.
 Due to high pressure AV Valve closes.

19. Complete Cardiac Diastole-
 It is the relaxation of atria & ventricle.
 It takes 0.4 Sec.
 After contraction of ventricle , there is complete
cardiac diastole of 0.4 Sec, when atria & ventricles
are relaxed.
 During this time, myocardium recovers & ready
for next beat & also atria refills for next cycle.