mass transport Flashcards
what are the three fundamental layers for blood vessels
1) outer layer
2) middle layer
3) internal layer
explain the function and adaptation of the outer layer
made up of collagen which makes it able to form tough layer around each blood vessel
explain the adaptation and function of the middle layer
made of muscle and elastic. The muscles contract and relax and the elastic fibres stretch and recoil.
why is the muscle thick in the arteries
vasoconstriction and vasodilation
why is the elastic thick in the arteries
maintains pressure
why is the lumen narrow in the artery
maintains blood pressure
are there valves in arteries
no
how are the muscles in veins
thin
how is the elastic in veins
thin
how is the lumen in veins and why
wide which reduces resistance therefore low pressure which maintains flow rate
are there valves in veins and why
yes because it prevents the backflow of blood
what is mass transport
movement of fluid in 1 direction through a pressure gradient through tubes
why is the heart described as a double pump
1 pump pumps blood to body and other goes to lungs
what is the function of pulmonary artery
deoxygenated blood away from heart to lungs to become oxygenated
what is the function of pulmonary vein
oxygenated blood into heart from lungs
what is function of aorta
oxygenated blood to rest of body
what is the function of the vena cava
deoxygenated blood from body to heart
what is the function of valves
ensure blood flows in only one direction through the heart
what is the function of the atrioventricular valve
ensures one way flow of blood and occurs between atria and ventricle
when do atrioventricular valves open/close
open- atrium contracts
close- ventricle contracts
when do semilunar valves open/close
ventricle contracts- opens
arterial pressure> ventricle =contracts
why is the left ventricle wall thick
because needs tp exert enough pressure to pump blood around the body
what is the function of the coronary arteries
supply heart muscle itself with blood
what is the cardiac cycle
the sequence of events that makes up one heart beat
what are the principles of the heart cycle
- the orientation of the heart valves
- the relative pressures of blood either side
- the reason for the relative pressures