Chapter 20 Capillary Beds Flashcards
vessels branching from meta arterial that make up the bulk of the capillary bed
true capillaries
a capillary bed or group of capillaries function together are fed by a?
metarteriole
proximal part of a capillary bed are encircled by scattered?
smooth muscle cells
distal part of the capillary bed, thoroughfare channel has no?
smooth muscle cells
__________ __________ connect to postcapillary venules, draining bed
thoroughfare channel
the proximal end of the thoroughfare channel is called the?
metarteriole
________ __________ make up the bulk of the capillary bed
true capillaries
smooth muscle ring at capillary origin, relaxes to permit blood to flow to True capillaries, contrax causing blood to bypass capillary bed
precapillary sphincter
_______: cycle of Contracting and relaxing of precapillary sphincters, at anytime 1/4 of bodies capillary beds are open
vasomotion
amount of light entering capillaries per unit time per gram of tissue?
( mL/min/gram) perfusion
________ are companion vessels with arterioles
venules
small and medium-sized veins are companion vessels with?
muscular arteries
largest veins are companion vessels with?
elastic arteries
most large veins have numerous valves to prevent?
blood from pooling in the limbs, and sure flow toward heart
what percentage of the blood is in systemic circulation?
70%
what percentage of the blood is in the heart at any given time?
12%
what percentage of the blood is in pulmonary circulation at any given time?
18%
A trashed majority of the blood in the body is in__________ _______ and function as blood reservoirs
systemic veins
55% of the blood is in?
systemic veins
5% of the blood is in?
systemic capillaries
10% of the blood is in?
systemic arteries
blood can be moved from veins into circulation via______________ and blood can be shifted back into reservoir as via ____________
vasoconstriction and vasodilation
blood can be moved from veins into circulation via vasoconstriction of veins when more blood is needed during _________
exertion
blood can be shifted back into reservoir is Vaya Vaso dilation when less blood needed during _____
rest
regulate blood flow through capillary beds?
precapillary sphincters
what are three different forms of capillaries from least permeable to most permeable?
continuous capillaries, fenestrated capillaries, sinusoid capillaries
one major artery delivers blood to an organ or region
simple pathway
an ____ ______ is an artery that provides only one path for blood to reach an organ or region
end
____________ joining together of blood vessels two or more vessels converge to supply or drain same region
anastomosis
_______ _________ two or more converging arteries to supply same region
arterial anastomosis
_______ ________ armoire comment then arterial anastomosis comma two or more veins drain same body region
venous anastomosis
____________ _________ (shunt) transports blood from artery directly to vein, allows areas to be bypassed if body hypothermic
atriovenous anastomosis
another name for a trio Venus anastomosis is?
a shunt
another name for a shunt is?
atriariovenous astomosis
this allows areas to be bypassed if body is hypothermic
arteriovenous anastomosis
what is a portal system?
two capillary beds in sequence
artery- capillary bed- portal vein- capillary bed - vein
_____ ____-______ _____ is the sum of diameters of all vessels of a certain type, collectively the total areas of capillaries is the largest because there are so many capillaries.
total cross-sectional area
______ _____ _______ is inversely related to Total cross-sectional area, blood flow is slow in capillaries, allowing for exchange between Blood and Tissue fluid
blood flow velocity
total cross-sectional area is __________ related to blood flow velocity
inversely related
larger total cross-sectional area lower blood flow velocity
how are substances exchanged across capillaries? ________ substances leave or enter blood according to their concentration gradient
diffusion ( high to low concentrations)
larger solids like some proteins pass through _________ or gaps in ________
fenestrations or gaps in sinusoids
small solids Like Oxygen can diffuse through __________ cells or ___________ _____
endothelial cells or intercellular clefts
true diffusion oxygen hormones nutrients move from blood to _________ _____
interstitial fluid
_______ _____ and ______ diffuse from tissue to blood
carbon dioxide and waste
in __________ _________ endothelial cells use pinocytosis and exocytosis, take substances in by pinocytosis. transport vesicle across South, secrete substances from Other Side by exocytosis
vesicular transport
certain hormones in fatty acids are transported across capillaries by?
vesicular transport, endocytosis and exocytosis
in this process fluids flow down pressure gradient, large amounts of fluids and dissolved substances move in a direction dependent pot pressure of opposing forces
bulk flow
the opposing forces in bulk flow are?
hydrostatic pressure vs. colloid pressure
in bulk flow _________ is when fluid moves out of blood, fluid and small solutes flow easily through capillaries openings, large solids blocked, occurs on arterial end of capillary
filtration
and bulk flow _________ is when fluid move back into blood, occurs at venous end
reabsorption
_________ pressure is the force exerted by a fluid comma in blood is the force exerted per unit area by blood on vessel wall, promotes filtration from capillary
hydrostatic pressure
two types of hydro static pressure at the capillary
blood hydrostatic pressure, interstitial fluid hydrostatic pressure
interstitial fluid hydrostatic pressure is close to_______ at most times
0/nothing
__________ promotes filtration from capillary
blood hydrostatic pressure
_______ _______ _______ pressure is osmotic pole do to protein salads
colloid osmotic pressure
what are two types of colloid osmotic pressure?
blood colloid osmotic pressure, interstitial fluid colloid osmotic pressure.
considering there are few proteins present in interstitial fluid ______ ________ _______ ______ pressure is relatively low
interstitial fluid colloid osmotic pressure
blood colloid osmotic pressure is clinically termed?
oncotic pressure
what type of pressure draws fluid into blood due to blood proteins slash promotes reabsorption
blood colloid osmotic pressure
how is net filtration pressure calculated?
net hydrostatic pressure - net colloid osmotic pressure= net filtration pressure
how do you calculate net colloid osmotic pressure?
blood colloid osmotic pressure - interstitial fluid colloid osmotic pressure
how do you calculate net hydrostatic pressure
subtract interstitial fluid hydrostatic pressure from blood hydrostatic pressure.
since interstitial fluid hydrostatic pressure is close to zero at most times it is typically just blood hydrostatic pressure
NFP stands for?
net filtration pressure
cop stands for
colloid osmotic pressure
HP stands for?
hydrostatic pressure