Chapter 21 Flashcards
elastic arteries are
pressure reservoirs and conducting arteries
vaso vasorum (what/where)
small vessels that supply blood to the tissues of the vessel and are is on the tunica externa
anastomosis
The union of the branches of two or more arteries supplying the same
body region
metarteriole
terminal end of the arteriole
arterioles known as
resistance vessels
microcirculation
The flow of blood from a metarteriole through capillaries and
into a postcapillary venule
capillaries known as
exchange vessels
capillary bed
a network of 10–100 capillaries that arises from a single metarteriole
thoroughfare channel
provides a direct route for
blood from an arteriole to a venule, thus bypassing capillaries
continuous capillaries vs fenestrated capillaries vs and sinusoids (what/where)
continuous tube with intracellular clefts; CNS, lungs, muscle tissue, skin
vs
have fenestrations; kidneys, villi of the SI, choroid plexuses of the ventricles in the brain, ciliary processes of the eyes, and most endocrine glands
vs
wider/windier, incomplete/absent basement membrane and large intracellular clefts; sinusoids of red bone marrow, spleen, anterior pituitary, parathyroid/adrenal glands
Usually blood passes from the heart and then in sequence through arteries, arterioles, capillaries, venules, and veins and then back to the heart. In some parts of the body, however, blood passes from one capillary network into another through a vein called a ______ vein. Such a circulation of blood is called a ____ _____
portal
portal system
BV increase of _____ have been measured in postcapillary and muscular venules
360%
Veins lack the internal or external ______ ______ found in arteries
elastic laminae
vascular sinus
vein with a thin endothelial wall that has no smooth muscle to alter its diameter
anastomotic veins
Some veins are paired and accompany medium to small-sized muscular arteries. These double sets of veins escort the arteries and connect via venous channels called anastomotic veins
The largest portion of your blood volume at rest, about ___, is in
systemic veins and venules so they function as _____ ______
64%
blood reservoirs
diffusions: capillary exchange method (importance, water/lipid soluble passes how/ex, what doesnt pass)
most important
water-soluble: pass through intracellular clefts/fenestrations (glucose/AA)
lipid soluble: directly through lipid bilayer of endothelial cell PM (O2, CO2, steroid hormones)
plasma proteins/RBCs cant pass unless its a sinusoid with large fenestrations
transcytosis: capillary exchange method (mainly for what/ex)
mainly for large, lipid-insoluble
molecules that cannot cross capillary walls in any other way (insulin/antibodies)
bulk flow: capillary exchange method (what for/how)
passive process in which large numbers of ions, molecules, or particles in a fluid move together in the same direction from higher to lower pressure
Diffusion is more important for _____ ____ between blood and interstitial fluid, but bulk flow is more important for regulation of the _____ _____ of blood and interstitial fluid.
solute exchange
relative volumes
Starling’s law of the capillaries
Overall, the volume of fluid and solutes reabsorbed normally is almost as large as the volume filtered
blood hydrostatic pressure (BHP) (number/due to/result)
35mmHg at arterial end of capillar, 16mmHG at venous end of capillary
due to the pressure that water in blood plasma exerts against blood vessel walls
“pushes” fluid out of capillaries into interstitial fluid
interstitial fluid hydrostatic pressure (IFHP)
0mmHg along capillaries
“pushes” fluid from interstitial spaces back into capillaries
Blood colloid osmotic pressure (BCOP) (number, caused by, result)
26 mmHg in most capillaries
caused by the colloidal suspension of these large proteins in plasma
“pull” fluid from interstitial spaces into capillaries
interstitial fluid osmotic pressure (IFOP)
0.1-5 mmHg
“pulls” fluid out of capillaries into interstitial fluid.
Thus, at the arterial end of a capillary, there is a net outward pressure
of ___ mmHg, and fluid moves out of the ______ into _____ _____ (filtration)
10
capillary
interstitial spaces
At the venous end of a capillary, the negative value (___ mmHg) represents a net inward pressure, and fluid moves into the _____ from tissue spaces (reabsorption)
-9
capillary
Blood flows from regions of _____ pressure to regions of _____ pressure; the greater the pressure difference, the _____ the blood flow. But the higher the resistance, the _____ the blood flow.
higher
lower
greater
smaller