Vessels Flashcards
what is important for maintaining high hydrostatic pressure?
smooth muscle in vessels
pressure in venous system?
low
pressure in arterial system?
high
what is considered macrovasculature
greater than .1mm in diameter, elastic arteries, muscular arteries, large arterioles, veins
what is considered microvasculature?
less than 0.1mm in diameter, arterioles, capillaries, post-capillary venules
composition of the tunica intima?
endothelium, basal lamina, subendothelial layer of loose connective tissue, internal elastic lamina
what is the internal elastic lamina?
a fenestrated sheet of elastin beneath the subendothelium
what is the internal elastic lamina most prominent in ?
muscular arteries
composition of tunica media?
concentric layers of smooth muscle, interspersed elastic fibers and type III collagen, contains the external elastic lamina in arteries
what is the tunica externa/adventitia
contains fibroblasts, type I collagen, elastic fibers oriented along longitudinal axes, merges with adjacent surrounding connective tissue, in large veins and elastic arteries there is the vasa vasorum
which are considered elastic arteries?
the aorta and all of its branches
characteristic of elastic arteries?
have thick walls with very high elasticity to help stabilize and maintain blood flow, elastin content makes vessel look kinda yellow
what are weibel-palade bodies
rodlike inclusions within the tightly packed ENDOTHELIAL CELLS, are the storage cells that contain and release von-willebrand factor and P selectin
where are weibel-palade bodies found?
tunica intima of elastic arteries
characteristics of the intima in elastic arteries
thick and typically folded
characteristics of the tunica media in elastic arteries?
most prominent, abundant concentrically arranged elastic fibers in the internal elastic lamina, scattered concentric smooth muscle, vasa vasorum (in larger vessels)
characteristics of tunica adventitia in elastic arteries
thins, have mainly fibroblasts, type I collagen, elastic fibers, and some vasa vasorum
what is P selectin
recruit circulating leukocytes to site of injury
where is the vasa vasorum found?
tunica media and adventitia to supply the vessel itself
where are the vasomotor nerve fibers found in the vessel??
near the tunica media to control vasoconstriction (thru norepi release)
what are aneurysms?
focal dilations in artery with at least 50% increase in vessel’s diameter
cause of aneurysm?
failure of major structural components due to congenital defect or acquired damage by chronic inflammation
common locations for aneurysm?
aorta, popliteal, mesenteric, splenic, cerebral arteries
what is atherosclerosis?
starts with endothelial injury, then chronic inflammation deposits lipid, collagen and possibly calcification in the intima
what could atherosclerosis cause?
narrowed lumen and impaired blood flow, hemorrhage, ulceration, aneurysm formation
what are vericose veins?
abnormal dilation and tortuosity of veins in pampiniform plexus caused by weakness in the media
what are the risk factors for vericose veins?
pregnancy, female, standing occupations, older age, obesity, smoking
characteristic of vericose veins?
reverse venous flow resulting in distended areas of pooled blood
common sites of vericose veins?
leg, anorectal region (hemorrhoids), lower esophagus (esophageal varices), spermatic cord (varicocele)
what is a cause of varicose veins?
increased intraluminal pressure, defect in structure or function of a valve
function of lymphatic system
transporting and collecting excess interstitial fluid from tissue spaces and return it to the blood, also distributes lymphocytes, antibodies, other immune components that are picked up at lymph nodes and other lymphoid tissues
describe the flow of lymph
lymphatic capillaries to larger lymphatic vessels, then to right lymphatic duct and thoracic duct
what allows the ISF to move?
moves from the plasma through the microvasculature by hydrostatic pressure
