Question

can an you please write Structure to function of heart

Answer 1

Structure of heart:

1. Shape ,walls and membrane:Heart is cone shaped having three membranes i.e endocardium (inner layer),myocardium (middle layer) and outer (epicardium layer) and all of these membranes are surrounded together by a sac like double membrane known as pericardium.
2. Chambers :There are 4 chambers: 2 atria and 2 ventricles.The left and right atrium receive blood from veins and pass it to the ventricles while the left and right ventricles receive blood from atrium and pass them into arteries.
3. Septum :Presence of septum that separates the right and left chambers of the heart from each other.
4. Muscular walls:The muscular wall of ventricles is thicker than that of atria and left ventricle is much thicker than right ventricle as it pumps blood to all other body parts.
5. Valves :Atrioventricular valves are present in between the atrium and ventricle.These include semilunar,bicuspid and tricuspid valves.Tricuspid valve is present between the right atrium and the right ventricle. The mitral valve is present between the left atrium and left ventricle.Two semilunar valves are present at the exit point of the ventricles each.
6. Blood vessels : Blood vessels associated with heart are superior and inferior vena cava,pulmonary artery,pulmonary vein and aorta.
7. Nerve supply:The vagus nerve innervates the heart along with the nerves arising from the sympathetic trunk.

Function of heart:

1. Heart functions in circulation of blood as below: Blood from the right ventricle  is pumped to the lungs.From lungs, blood flows  back into the left atrium and then to the left ventricle.Blood from the left ventricle is then pumped through out the body but not the lungs.Blood returns to the heart via right atrium through vena cava.
2. Muscular contraction:The heart is made up of cardiac muscle which are specialised muscles that fucntions to contracts and relaxes regularly, throughout life thereby helping in proper pumping action of heart.It also receives oxygen and glucose for its own activity by the blood from coronary artery.
3. Functioning of valves :Valves prevent back flow of blood that is pumped from atria to ventricles when the heart ‘beats