heart Flashcards
what is stroke volume
the volume of blood pumped from left ventricle of the heart with each beat (cm3)
what is heart rate
number of times the heart beats in 1 minute. time for 1 cardiac cycle to happen
what is cardiac output
the volume of blood which leaves the left ventricles in 1 min (cm3 or dm3/min-1)
what is the pulse
a regular pulsing of the arteries as blood is propelled through them due to contraction of the heart (bpm)
what is the cardiac output
stroke volume x heart rate
what is the role of the arteries
carry blood away from the heart
what is the role of arterioles
Carry blood from arteries into capillaries.
what is the role of capillaries
Site of diffusion between blood and body tissues.
what is the role of the veins
carry blood towards the heart
describe the arteries
-blood pressure= high
-muscle=thick muscular walls-constrict and dilate-control volume of blood passing through
- elastic layer=larger- stretching and recoiling=smoothes pressure
-thick vessel wall=high pressure
-no valves
describe the arterioles
blood pressure=low but higher then veins
-no valves
-vessel wall= smaller diameter than arteries
- elastic layer= thinner than arteries
- muscle layer=larger compared to arteries. contraction- controls flow between arteries and capillaries
describe the veins
-blood pressure- low
-muscle layer= very thin- carries blood from tissue so no contraction and dilation needed
-elastic layer=very thin=low pressure
-valves needed to prevent back flow
-vessel wall- small- veins are compressed
-large lumen
describe the capillaries
-single layer of flattened endothelia cells to reduce diffusion distance
-gaps=allow move out of gases
-blood low pressure
-lumen-wide for 1 cell to travel through
-capillaries merge to form venules
