Structure of the heart - topic 3 Flashcards
(21 cards)
The walls of the heart have a thick muscular layer, what is it called?
The cardiac muscle
give the 2 properties of the cardiac muscle
myogenic - contract and relax without nervous or hormonal stimulation
it never fatigues, as long as it has a supply of oxygen
give the role of the coronary arteries
supply the cardiac muscle with oxygenated blood
these branch off from the aorta
what happens if the coronary arteries become blocked?
cardiac muscle won’t receive oxygen, therefore will not be able to respire and the cells will die
this results in a heart attack
give the four chambers of the heart
2 atria : left atrium, right atrium
2 ventricles : left ventricle, right ventricle
describe the structure of the atria
thinner muscular walls
do not need to contract as hard as not pumping blood far
elastic walls to stretch when blood enters
describe the structure of ventricles
thicker muscular walls to enable bigger contraction
this creates a higher blood pressure to enable blood to flow longer distances
describe the right ventricle
pumps blood to the lungs
this needs to be at a lower pressure to prevent damage to capillaries in the lungs and so blood flows slowly to allow time for gas exchange
thinner muscular walls in comparison to the left ventricle
describe the left ventricle
pumps blood to the body
this needs to be at a higher pressure to ensure blood reaches all the cells in the body
much thicker muscular wall in comparison to the right ventricle to enable larger contractions of the muscle to create higher pressure
Pulmonary meaning
refers to the lungs
describe the vena cava
(means body vein)
carries deoxygenated blood from the body into the right atrium
describe the pulmonary vein
carries oxygenated blood from the lungs to the left atrium
describe the aorta
carries oxygenated blood from the left ventricle to the rest of the body
describe the pulmonary artery
carries deoxygenated blood from the right ventricle to the lungs to become oxygenated
give the two types of valve
semi-lunar valves
atrioventricular valves
where are the semi-lunar valves
in aorta and pulmonary artery
where are the atrioventricular valves
between atria and ventricles
what side is the bicupsid
left side
what side is the tricupsid
right side
describe what the valves do
open when pressure is higher behind the valve
close when pressure is higher in front of the valve
prevent baclflow of blood
describe the role of the septum
separates the deoxygenated and oxygenated blood
maintains high concentration of oxygen in oxygenated blood to maintain concentration gradient to enable diffusion to respiring cells
