The Heart Flashcards
What is the heart wall made of?
thick cardiac muscle layer
→myogenic - can contract and relax without nervous or hormonal stimulation
→ never fatigues as long as there is a supply of oxygen
What is the function of the coronary arteries?
supply the cardiac muscle with oxygenated blood
→ they branch of from aorta
What happens if coronary arteries become blocked?
cardiac muscle wont receive oxygen and wont be able to respire and the cells will die which causes a heart attack (myocardial infarction) → by pass surgery required
What is the structure of the atria?
thinner muscular wall as its only pumping blood to the ventricles so don’t need to contract hard and elastic walls to stretch when blood enters
What is the structure and function of the right ventricle?
pumps blood to lungs so needs to be at a lower pressure to prevent damage to capillaries and give time for gas exchange = thinner wall than left ventricle
What is the structure and function of the left ventricle?
pumps blood to t he body which needs to be at higher pressure to ensure blood reaches all cells in body = thicker walls due to need for larger contractions to give that higher pressure
What is the function of the vena cava(e)?
carries deoxygenated blood from the body into right atrium
→ superior = from head + neck
→ inferior = from rest of lower body e.g. legs
What is the function of the pulmonary vein?
carries oxygenated blood from the lungs to the left atrium
What is the function of the pulmonary artery?
carries deoxygenated blood from the right ventricle to the lungs to be oxygenated
What is the function of the aorta?
carries oxygenated blood from the left ventricle to the rest of the body
What is the function of the semi-lunar valves?
prevents backflow in pulmonary artery and aorta
When are semi-lunar valves open?
when pressure in ventricle is higher than in arteries
What is the function of atrioventricular valves?
between the atria and ventricle
→bicuspid = left side
→ tricuspid = right side
When are atrioventricular valves shut?
when pressure is higher in ventricles than atria
