Topic 5 - The Heart Flashcards
what does the right atrium receive?
deoxygenated blood from the vena cava
where does deoxygenated blood go after the right atrium?
through to the right atrium, which pumps it to the lungs via the pulmonary artery
what does the left atrium receive?
oxygenated blood from the pulmonary vein
where does oxygenated blood go after the left atrium?
through to the left ventricle, which pumps it towards the whole body via the aorta
which ventricle has a thicker wall?
the left one
why does the left ventricles have a thicker wall?
it needs more muscle because it has to pump blood around the whole body. blood in the left ventricle is also under higher pressure
what are the three valves in the heart?
the semi-lunar valve, tricuspid valve and the bicuspid valve
where are the semilunar valves?
between the ventricles and the vein/artery
where is the tricuspid valve?
between the right atrium and the right ventricle
where is the bicuspid valve?
between the left atrium and the left ventricle
what do the valves in the heart do?
prevent the backflow of blood
why does heart rate increase when exercising?
exercise increases the amount of carbon dioxide in the blood. this is detected by receptors in the aorta and carotid artery. these receptors send signals to the brain, which sends signals to the heart, causing it to beat faster.
how does the hormonal system control heart rate?
when an organism is threatened the adrenal glands release adrenaline. this binds to specific receptors in the heart, increasing the heart rate.
