Cardio 5 Flashcards
tone
a state of partial contraction at all times
Arteriole diameter is controlled by..
tonic release of norepinephrine
increase norepinephrine release onto alpha receptors
blood vessel constricts
decrease norepinephrine release onto alpha receptor
blood vessel dilates
microcirculation
arterioles, capillaries, and venules
metarterioles
act as a capillary bypass vessel located across microcirculations
Where does majority of exchange between blood and interstitial space occur?
capillaries
Capillaries contain a single thin endothelial layer surrounded by..
a basal lamina (extracellular matrix)
fenestrations
membrane lined conduits running through cells to allow transport
continuous capillary
most common; thicker endothelial cells with no fenestrations and only allow passage of water and small ions through tight junctions
fenestrated capillary
thin endothelial cells perforated with fenestrations with thin diaphragm for small molecules
discontinuous capillary
no basal membrane; contain large fenestrations and gaps between endothelial cells
transcellular transport
diffusion across endothelial cell membrane
paracellular transport
diffusion through interendothelial junctions, pores and fenestrations
transcytosis
combination of endocytosis, vesicular transport, and exocytosis that transport macromolecules across endothelial cells
volume reservoir
venous circulation; systemic veins
pressure reservoir
systemic arteries (ventricular relaxation)
angiogenesis
formation of new blood vessels
Adult microcirculation is rather constant with the exceptions of..
vessel growth during wound healing, endurance training, inflammation, tumor growth and in the endometrium during the menstrual cycle
angiogenic grwoth factors
activate receptors on endothelial cells
activated endothelial cells
produce proteases that degrade the basal lamina so it can move away from the parent vessel and proliferate into surrounding matrix to form sprouts that form loops to become vessel lumen
promoters of angiogenesis
vascular endothelial growth factor (VEGF), fibroblast growth factors (FGFs) and Angiopoietin 1
inhibitors of angiogenesis
endostatin, angiostatin, and angiopoietin 2
ventricular contraction
creates force necessary to propel blood through cardio system causing them to stretch
ventricular relaxation
semilunar valve shuts preventing flow back into ventricle and elastic recoil of arteries sends blood forward into rest of circulatory system
blood pressure highest in __________ and ___________ throughout circuit
aorta, decreases
aortic pressure highest during ________ and lowest during _________.
systole, diastole
pulse pressure
systolic pressure - diastolic pressure
pulse pressure normally only exists on ….
arterial/arteriole side of circuit
mean arterial blood pressure
diastolic pressure + 1/3(pulse pressure)
hypotension
when blood pressure falls too low
hypertension
when blood pressure is chronically elevated
hypertension can cause…
vessel walls to weaken and rupture/leak (aka, stroke/cerebral hemorrhage)
