Nov15 M3-Regional Circulations Flashcards
brain AV diff, O2 cons and flow
medium
cerebral flow as fct of BP
normal no matter BP but drops below 60 mmH
hyperemia (active hyperemia)def
increase in blood flow to an organ due to increased requirements
active hyperemia vs flow autoregul
less O2 and increased metabolites act on SM (not bc drop BP but increased demand)
substance that causes dilation of arterioles in brain
CO2
situation where CBF increases
seizures
response to vessel leak in brain
increased venous P, general ANS activation and vasoconstriction to raise BP
name of response to leak in brain
CNS ischemic reflex
general name of ischemic reflexes
Cushing Response
blood brain barrier (2 improtant things)
tight junctions
lot of mts bc lot of active transport
organs with a blood-organ (blood brain like barrier) and one that doesn’t have it
brain, spinal cord, CSF
muscle doesn’t have that
lung vs rest body respone to low O2
vasoconstriction
rest of body: vaosdilation
kidney AV diff, O2 cons and flow
high but low AV diff
kidney 2 moments where substances exchange between blood and kidney
glomerular capillaries (go out) and vasa recta (peritubular capillaries) (go back in)
GFR def
amount of fluid filtrated in tubules
what organs give blood to portal vein
stomach, spleen, panchreas, small intestine, colon
liver AV diff, O2 cons and flow
high flow
origin of flow to liver
75% from portal vein
25% from hepatic artery
ascites def and cause
fluid in abd cavity
portal htn
muscle AV diff, O2 cons and flow
least flow at rest
vascular tone effect on SKM at rest vs exercise
rest: SS tone: very constricted
exercise: SS largerly outweighted by waste products (flow increase x30)
skin 2 roles
protection + thermoregul
skin AV diff, O2 cons and flow
lowest
3 types of heat transfer
conduction: skin to air
convection: hot air to cold air
IR radiation
reactions to cold
shivering, random chaotic reaction, frostbite
frostbite def
blood not directed to extremities
what gives skin coloration
deep venous plexus
countercurrent exchanger
shunt of heat from arteries to vein when to protect temp when needed
temp as fct of O2 consump
linear increase
why evaporation important way to lose heat
water needs high T to evaporate. when does so, takes lot of heat
flow to skin when exercise
goes up
loss of evaporation as fct of temperature
increases linearly
