CV6 Flashcards
is vascular smooth muscle always in a state of contraction
yes
where is the smooth muscle layer in a vascular smooth muscle
media (the middle one)
what make up the microcirculation
arterioles, capillaries, and venules
what is a metarteriole?
why isn’t it an arteriole
act as a bypass channel
not quite an arteriole because its not fully vascular smooth muscle
what are precapillary sphincters
vascular smooth muscle at the junctions between the arterioles and capillaries
what are the walls of arteries like
stiff and springy
are metarterioles thicker or thinner than capillaries
thicker
gases can normally ___________ across the endothelial cells
passively diffuse
what are capillaries linked by
interendothelial junctions
what are fenestrations? where are they located
pores along the membrane that allow transport
cells
what are capillaries usually surrounded by
pericytes (like a blood brain barrier)
what is the most common capillary
continuous capillary
which capillary does not contain fenestrations
continuous
which capillary has the least amount of transport and exchange
continuous
which capillaries have fenestrations
fenestrated and discontinued
which capillaries have a thin diaphragm making them selective
fenestration capillaries
which capillaries are found in the liver and spleen
discontinuous (sinusoidal)
what are the three methods of transport in capillaries
transcellular transport
paracellular transport
transcytosis
what is transcellular transport in capillaries
diffusion across the endothelial cell membrane
(aquaporin channels)
what is paracellular transport in capillaries
diffusion through inter endothelial junctions, pores, or fenestration
what is transcytosis In capillaries
endocytosis, vesicular transport, etc
are there more veins or arteries
more veins. that is why they are the volume reservoir
do arteries or veins have a thinner layer of vascular smooth muscle and elastic tissue
veins do
what is angiogenesis
the formation of new blood vessels
is adult microcirculation constant
yes
what is a major driver of blood vessel growth
vascular endothelial growth factor
what circuit is blood pressure related to
systemic circuit
why are arteries the pressure reservoirs
they ensure that blood continues to flow even during ventricular relaxation
there is a pressure gradient at all times because they store pressure in elastic walls
when is aortic pressure highest
ventricular contraction (systole)
how to calculate pulse pressure
pulse pressure = systolic pressure - diastolic pressure
where does pulse pressure usually exist
the arterial/arteriole side of the circuit
can a pressure wave be felt
yes
what is the mean arterial blood pressure
reflects the driving pressure for blood flow (commonly measured in bicep as a reflection of ventricle driving pressure
mean arterial blood pressure calculation
map = Diastolic + 1/3 (systolic - diastolic)
is the MAP an average of systolic and diastolic pressures? why or why not
no, because the time spent in systole is shorter than the time spent in diastolic
what is hypotension
when the blood pressure is chronically toon low (lower than 90/60)
what is hypertension
when the blood pressure is chronically higher (over 140/90)
what is a blood leak in the brain called ? what is it caused by
cerebral hemorrhage
could be because of hypertension leading to weakened vessel walls
what is blood pressure estimated by
sphygmomanometer
what is a Karotkoff sound? what is it caused by
it is the audible sound of whooshing of blood
it is caused by pulsatile blood flow through the compressed artery
