LESSON 18 - venous return and the pulmonary circulation Flashcards
describe venous circulation :
a conduit return blood to the right side of the heart from the periphery
describe the type of blood veins circulate :
veins return oxygenated blood to the heart but deoxygenated blood in rest of the body
how many reservoirs for blood volume ?
5
what are the 5 reservoirs for blood volume ?
- pulmonary
- veins
- heart
- arteries
- arterioles, capillaries
what % of “reservoir” for blood volume is in the pulmonary ?
9%
what % of “reservoir” for blood volume is in the veins ?
64%
what % of “reservoir” for blood volume is in the arterioles & capillaries ?
7%
what % of “reservoir” for blood volume is in the arteries ?
13%
what % of “reservoir” for blood volume is in the heart ?
7%
what is venous return (VR) ?
volume of blood that returns from the veins to the ratio each minute
FILL IN THE BLANK
“venous return = rate of blood return from the ____ to the _____ “
veins to the atrium
describe the venous return and cardiac output closed loop :
right ventricle … pulmonary … left ventricle … systemic …
where within the closed loop do we see VR (venous return) ?
systemic to right ventricle
where within the closed loop do we see CO (cardiac output) ?
right ventricle to pulmonary and left ventricle to systemic
FILL IN THE BLANK
venous return = _________ = _________
right ventricle output = left ventricle output
TRUE OR FALSE
all pumps have to be operated at the same speed
TRUE
why must all pumps have to be operated at the same speed ?
to sustain that high level of cardiac output
during exercise, an increase in venous return = ?
increase right ventricle and left ventricle filling
how does venous return increase ?
during exercise (think of cardiac output)
what is the formula for venous return (VR) ?
VR = ΔP / TVR
what is TVR ?
resistance in the large veins and vena cave
what is ΔP ?
pressure differential
what is P venous (peripheral venous pressure) ?
pressure in the peripheral veins draining tissues
which part of the venous return system is the highest point of pressure ?
the beginning of the system
which parts of the circulatory system are a high pressure system and high resistance ?
- left ventricle
-arteries - arterioles
which parts of the circulatory system are a low pressure system and low resistance ?
- venules
- veins
between arteries and veins which have more smoother muscles ?
arteries
within the circulatory system which are the exchange vessels ?
capillaries
do we see low or high resistance in the venous circulation ?
low resistance
describe the anatomy of veins :
- thinner walls
- lack of smooth muscle
- lack of sympathetic tone
- more compliant
describe the anatomy of arteries :
- thicker walls
- lots of smooth muscle
- more elasticity
- easier to return to original state