blood moving throughout body Flashcards
right atrium
receives blood from body and passes it to the right ventricle
right ventricle
pumps blood to lungs
left atrium
receives blood from the lungs and passes it to the left ventricle
left ventricle
pumps blood to the rest of body
- wall of LV is thicker than wall of RV, because it needs to me much stronger when pumping blood through vessels
atrioventricular valves purpose - 2 types, their location and # of cusps/flaps
when the ventricles contract, the blood catches behind the flaps and seals off the opening between the atrium and ventricles, stops so blood must then leave the heart through the arteries and not flow back into the atria
1. tricuspid valve is located between the RA and RV, it has 3 flaps/cusps
2. bicuspid valve is located between the LA and LV and has 2 flaps/cusps
semilunar valves - 2 types, their location and # of cusps/flaps
when arteries leave heart, second set of valves that stop blood from flowing back into ventricles
1. pulmonary valve is located between the RV and pulmonary after and has 3 cusps
2. aortic valve is located between the LV and the aorta and has 3 cusps
circulation definition
the same blood flowing continuously through the heart
arteries
carries blood AWAY from the heart
- contain smooth muscle and elastic fivers
- ventricles contact and push blood into arteries
- the walls of arteries stretch to accomodate the extra blood
- when ventricles relax, the elastic artery recoils, this elastic recoil helps maintain blood pressure and keep it moving
^ they can contact swell to reduce diameter (vasoconstriction to reduce BF to an organ) and stretch to increase diameter (vasodilation to increase BF to an organ)
capillaries
the link between the arteries and veins
veins
carry blood TOWARDS the heart
veins and venues do not have muscular walls and are not able to change diameter
- BP in veins is relatively low, because blood lost most of its pressure as it flows through the tiny capillaries
- much thinner.
cardiac cycle
heartbeat - sequence of events that occurs In ONE complete beat of the heart
systole: the pumping ogees when the heart muscle contracts
diastole: the filling phase when the heart muscles relax
for a short time, both atria and ventricles are in diastole
^ during this phase, the atria fill with blood and ventricles also receive blood as valves are open
atrial systole: contraction of atria that forces the remaining blood into the ventrictures
the atria then relax and refill while ventricles contract in:
ventricular systole: forces blood into arteries
cardiac output
cardiac output (mL/minute) = stroke volume (mL) x heart rate (beats per minute)
