Flashcards in Vascular Path Robbins Part 1 Deck (66)
blood vessels- 3 concentric layers
(internal elastic lamina)
(external elastic lamina)
intima- consists of
-endo cells (single layer) on basement membrane
-demarcated from the media by internal elastic lamina
media- consists of
smooth m cells
media- in elastic a's (aorta)
-have high elastin content
media- in muscular a's
-composed predominantly of circumferentially oriented smooth m cells
-smooth m contraction and relaxation- reg by inputs from autonomic NS and local metabolic factors
principal points of physiologic resistance to blood flow
adventitia- consists of
-separated from the media by external elastic lamina
-loose CT containing n fibers, vasa vasorum (small arterioles that supply the outer portion of the media)
a's divided into 3 types
-large/elastic arteries (aorta, major branches of aorta)
-medium-sized/muscular a's- smaller branches of aorta)
-small a's (<2 mm diameter) and arterioles (20-100 um diameter)
capillaries- size? consists of
-7-8 um diameter (size of red cell)
-have endo cell lining, but no media
-pericytes (resemble smooth m cells) lie deep to endo
veins- diff from a's
-larger diameters, larger lumens, thinner/less organized walls
-contains 2/3 of total blood volume
-less rigid walls-subject to dilation and compression, as well as infiltration by tumors and infl process
-thin-walled channels- lined by specialized endo
-provide conduits to return interstitial tissue fluid and infl cells to bloodstream
-can also transport microbes and tumor cells- important potential pathway for disease dissemination
berry aneurysms- found where? asssoc with? can cause?
-circle of willis
-autosomal dominant polycystic kidney disease
-fatal subarachnoid hemorrhage
arteriovenous fistulas- arise from? can cause?
-direction connections b/w a's and v's that bypass the capillary bed
-most often developmental defects
-may arise secondary to infl, trauma, rupture
-can rupture- leads to hemorrhage
-can cause high-output cardiac failure- by shunting blood from arterial to venous circulation, forcing heart to pump additional volume
-focal thickening of intima and media of medium/large muscular a's- results in stenois
-"string of beads"
-young women- most often
endo cells- normal state
endo cells- activated state- what stimuli?
-turbulent blood flow
-complement, bacterial products, lipid products, glycation end products
-tobacco smoke components
activated endo cells- characterized by expression of?
-vasoactive factors, GFs
endothelial dysfxn- characterized by?
-smooth m stimulation
-partly responsible for initiation of thrombus formation, atherosclerosis, and vascular lesions of HTN
predominant cellular element of vascular media- fxns
vascular smooth m cells
-roles in vascular repair and pathologic processes
-can proliferate when stimulated
-can syn collagen, elastic, proteoglycans, GFs, cytokines
-responsible for vasoconstriction.dilation
vascular injury- assoc with?
endo cell dysfxn or loss
-stim smooth m recruitment/proliferation (from media to intima)
-assoc matrix syn
vascular injury- stereotypical response?
HTN- risk factor for?
-atherosclerosis, aortic dissection
-Hypertensive heart disease (cardiac hypertrophy and HF)
-hypertensive renal disease
hypertensive vascular disease- increased prevalence in?
90-95% of HTN- cause?
-idiopathic (essential HTN)
5% of HTN- cause?
-renal or adrenal disease
-renal a stenosis
risk factors for essential HTN
-high Na intake
malignant HTN- characterized by?
-small % of HTN pts show a rapidly rising BP that if untreated leads to death within 1-2 yrs
-severe HTN (>200/120), renal failure, retinal hemorrhages/exudates
CO x PVR
(CO= SV x HR)