Physiology Tutorial

1. Physiology Tutorial CVS

2. Functional Anatomy of the HEART What are the basic components of the Circulatory System? 1. Heart 2. Blood 3. Blood Vessels • What are the two vascular loops of the circulatory system? 1. Pulmonary Circulation 2. Systemic Circulation

3. Functional Anatomy of the HEART What is the function of the atrium? • Receive blood returning to the heart and transfer it to the ventricle What is the function of the ventricle? • Pump the blood from the heart to the arteries

4. Functional Anatomy of the HEART • List the facts about the pulmonary circulation? • Closed loop of vessels carrying blood between the heart and the lungs • Right atrium receives deoxygenated blood from all parts of the body • Right ventricle pump deoxygenated blood through pulmonary artery the to the lungs.

5. Functional Anatomy of the HEART List the facts about the systemic circulation? • Circuit of vessels carrying blood between the heart and other body systems • Left atrium receive oxygenated blood through pulmonary vein from the lungs. • Left ventricle pump oxygenated blood through the aortic artery to the systemic circulation.

6. Functional Anatomy of the HEART What is the function of the septum? Prevents mixture of blood from the right and left sides of the heart Right and left atrium are separated from each other by interatrial septum Right and Left ventricle are separated by interventricular septum

7. Functional Anatomy of the HEART List the facts about heart valves? • 1. There are four valves 2. They are one way valve 3. Valves open and close passively because of pressure difference 4. Function of the valve is to prevent back flow of the blood

8. Functional Anatomy of the HEART What are the four valves of the heart? Two Atrioventricular Valves (AV valves): i) Right AV valve ii) Left AV valve Two Semilunar Valves: i) Aortic valve ii) Pulmonary valve • AV valves are attached to the papillary muscle and chordaetendineae

9. Functional Anatomy of the HEART Where is the location of AV valves? • Right and left AV valves are positioned between atrium and ventricle on right and left sides • Right AV valve also called tricuspid valve • Left AV valve also called bicuspid valve or mitral valve What is the function of AV valves? • Prevent backflow of blood from the ventricles into atria during ventricular contraction

10. Functional Anatomy of the HEART Where is the location of the semilunar valves? Aortic Valve is present at the beginning of the aorta and has three cusps Pulmonary Valve is present at the beginning of pulmonary artery and has three cusps What is the function of the semilunar valves? They prevent back flow of the blood from the arteries to the ventricles

11. Functional Anatomy of the HEART What is the facts about the left side of the heart? 1. Associated with the systemic circulation. 2. Receives oxygenated blood from the pulmonary circulation. 3. Pumps the blood through the aortic artery to the systemic circulation. 4. Carries oxygenated blood.

12. Functional Anatomy of the HEART What is the facts about the right side of the heart? 1. Associated with the pulmonary circulation. 2. Receives venous return from all parts of the body. 3. Pumps the blood through the pulmonary artery to the lungs. 4. Carries deoxygenated blood.

13. Functional Anatomy of the HEART Compare between the right and left pumps?

14. Functional Anatomy of the HEART Trace a drop of blood through one complete circuit of the circulatory system? The venaecavae are veins returning blood to the right atrium. Oxygen has been extracted from this blood. Carbon dioxide has been added to it. This blood is pumped from the right ventricle through the pulmonary artery to the lungs. The lungs add oxygen to this blood received from the right side of the heart. Carbon dioxide is removed from this blood. This blood flows through pulmonary veins to the left atrium of the heart. This oxygen rich blood is pumped from the left ventricle through the aorta, a large artery.

15. Functional Anatomy of the HEART • What keeps the heart valve from everting? • Chordaetendineae are tendon like tissue and their function is prevent the eversion or bulging of valves into atria. • What is the function ofpapillary muscle? Chordaetendineae are attached to papillary muscle which protrude from inner surface of atrioventricular valve When ventricle contract, papillary muscle also contract and pull down the chordaetendineae, which keeps the valve tightly closed.

16. Functional Anatomy of the HEART What are the three layers of the heart wall? Endothelium – inner lining of the heart Myocardium – cardiac muscle tissue Pericardium – external layer

17. Functional Anatomy of the HEART Describe the distinguishing features of cardiac muscles? Cardiac muscle fibers are connected by membrane called (INTERCALATED DISC) • Within intercalated discs there are two kinds of membrane junctions • 1. Desmosomes • 2. Gap junctions • Gap Junction allow diffusion of ions. Action potential travels from one cell to another easily. Cardiac muscle works as SYNCYTIUM (one unit). The heart can be depolarized all at one time. It obeys all or none law.

18. Functional Anatomy of the HEART What is the effect of autonomic nervous system on the heart? Heart is supplied by sympathetic and parasympathetic nerves Sympathetic stimulation causes increased heart rate and force of contraction. Parasympathetic stimulation decreased heart rate and force of contraction.

19. Functional Anatomy of the HEART Is the atria and ventricle each act as a functional syncytium ? There is atrial syncytium and ventricular syncytium Atria and ventricle contract as a separate units as they are separated by non-conducting fibrous ring The impulse travels from the atria to the ventricle by specialized conductive tissue

20. Functional Anatomy of the HEART What is the fibrous skeleton of the heart? In between atria and ventricles, there is fibrous ring. It is dense connective tissue. It provides base for attachment of the four heart valves. Atrial muscle is attached to upper part and ventricular muscle is attached to the bottom of the ring.