Chapter 20 Flashcards
Conducting arteries
elastic or large arteries
biggest arteries
examples common carotid subclavian pulmonary trunk aorta
distributing arteries
muscular or medium arteries
distributes blood to specific organs
examples: femoral brachial renal and splenic arteries
Resistance arteries
small
arterioles: smallest arteries
thicker tunica media in proportion to their lumen than large arteries.
very little tunica external
In carotid sinuses
baroreceptors
carotid bodies
chemoreceptors
aortic bodies
chemo/baroreceptors
exchange vessels
capillaries
composed of endothelium and basal lamina
capillaries
there types of capillaries
continuous fenestrated and sinusoids
intercellular clefts in the continuous capillaries allow
passage of small solutes such as glucose
what type of capillary occur in most tissues
continuous capillaries
least permeable and most common capillary
continuous capillaries
endothelial cell riddled with holes call filtration pores are what type of capillary
fenestrated capillary
discontinuous capillaries
sinusoids
most permeable capillary
sinusoids
allows proteins clotting factors, and new blood cells to enter the circulation
sinusoids
ateriovenous anastomosis
(shunt) artery flows directly into vein bypassing capillaries
Venous anastomosis
most common
—- vein blockage is less serious than arterial blockage
arterial anastomosis
provides collateral (alternative rate) of blood supply to a tissue
what anastomosis is common around joints and coronary circulation
arterial anastomosis
what are the two factors of cardiac output?
heart stroke and pressure
if cardiac output goes up, what happens to BP?
goes up
blood volume is regulated mainly by the
kidneys ( blood is filtered by the kidneys)
if blood volume goes up what happens to BP
goes up
three ways of controlling vasomotor activity
local control
neural control
hormonal control
baroreflexes
Neural control
short term regulation
baroreflexes sense if heart rate is up than neural control slows heart rate down
if Baroreflexes sense heart is down the neural control speeds heart rate up
chemoreflex
response to changes in pH, O2 and CO2
hypoxemia hypercapnia and acidosis stimulates (vasoconstriction or or vasodilation)
vasoconstriction
this increases blood pressure which increases lung
( a reflex ) automatic response to a drop in perfusion of the brain
medullary ischemic reflex
medullary ischemic reflex causes an
increase in heart rate and contraction force
causes widespread vasoconstriction
raises bp and restores normal perfusion to the brain
Angiotensin II
potent vasoconstrictor causes bp to rise
-promotes sodium and water retention by kidneys
atrial natriuretic peptide
increases urinary sodium excretion reduces blood volume and promotes vasodilation which decrease bp
ADH promotes water retention
raises blood pressure
epinephrine and norepinephrine
blood pressure goes up.
blood hydrostatic pressure is produced by
blood pressure. which pushes small stuff out by normal blood flow ( blood pressure)
colloid osmotic pressure is produced by
tendency of water to want to go back in after being pushed out. water wants to go back in because there is “big stuff” in the vessels still
capillaries reabsorb about 85% of the fluid they filter by hydro static pressure what happens to the 15%
lymphatic system absorbs it and the returns to the blood after its cleaned
capillary filtration occurs at (arterial or venous) end
arterial end
capillary reabsorption occurs at ( arterial or venous) end
venous end
what are the exceptions of capillary filtration and absorption
kidney capillaries and alveolar capillaries
kidney capillaries in glomeruli
kidney capillaries in glomeruli don’t reabsorb
alveolar capillaries in lung
absorbs completely to keep fluid out of air spaces
