Chapter 14 - The Cardiovascular System: Blood Vessels, Blood Flow, & Blood Pressure Flashcards
the rate at which the heart pumps blood into the vasculature
cardiac output
air flowing out of a balloon or blood flowing through vessels
bulk flow
CVP
central venous pressure
Blood flow is greater when _____ is lower.
resistance
measure of the degree to which the tube hinders flow of liquid through it
resistance
decrease in vessel radius
vasoconstriction
increase in vessel radius
vasodilation
What are the three things that determine resistance?
- vessel radius
- vessel length
- blood viscosity
flow rule for systemic circuit
CO = MAP/TPR
Flow = _____
pressure gradient/resistance
TPR
total peripheral resistance
combined resistance of all the blood vessels within the systemic circuit
TPR (total peripheral resistance)
Which blood vessels are part of the microcirculation?
arterioles, capillaries, and venules
lining of the lumen of a blood vessel
endothelium
gives tensile strength to walls of blood vessels
collagen
As arteries get smaller, _____ decreases and _____ increases.
elastic tissue; smooth muscle
As arteries get smaller, _____ decreases and _____ increases.
elastic tissue; smooth muscle
internal diameter of aorta
12.5 mm
wall thickness of aorta
2 mm
arterial blood pressure
pressure in the aorta
pulse pressure (PP) = _____
systolic pressure - diastolic pressure
_____ is the average arterial pressure during the cardiac cycle.
Mean arterial pressure (MAP)
Resistance to blood flow can be regulated in the _____.
arterioles
passageway for blood to enter capillaries
arterioles
a condition in which blood flow in a tissue is insufficient to keep up with metabolic demand
ischemia
Blood flow gets distributed to organs based on _____.
need
Intrinsic control mechanisms are especially important in regulating blood flow to _____.
heart, brain, and skeletal muscles
_____ are the primary site for exchange of nutrients & waste products.
Capillaries
least permeable of capillaries
continuous capillaries
_____ capillaries have no basement membrane.
Discontinuous
capillary type found in kidneys, intestines, and endocrine glands
fenstrated
capillary type found in spleen, liver, and bone marrow
discontinuous
allow blood to flow from arteriole directly to venule, bypassing capillaries
metarterioles or shunts
When resistance is high, flow through capillary beds (increases/decreases).
increases
NFP
net filtration pressure
filtration
blood —> interstitial fluid (arteriole end)
absorption
interstitial fluid —> blood (venule end)
swelling of tissues caused by a shift in fluid from plasma to interstitial fluid
edema
osmotic pressure that is exerted by proteins
colloid osmotic pressure
the difference in the filtration pressures and the absorption pressures
net filtration pressure
Venules consist of a single layer of _____.
endothelium
Blood pressure in veins is slightly _____ than in arteries.
lower
diameter of vena cava
30 mm
wall thickness of vena cava
1.5 mm
Veins are _____ reservoirs.
volume
Veins have (high/low) compliance.
high
_____ have one-way valves that permit blood to flow toward the heart, but prevent it from flowing back toward organs and tissues.
Peripheral veins
Factors that Affect Venous Pressure
- skeletal muscle pump
- respiratory pump
- blood volume
- venomotor tone
accumulation of blood in the veins
venous pooling
hypertension
elevated MAP
