Blood vessels exam Flashcards
arteries are
efferent and divergent
Veins are
afferent and convergent
capillaries are
exchange vessels
Tunica intima
inner most layer of vessels made of endothelium and elastic lamina
tunica media
middle layer of vessels made of smooth muscle
tunica externa
outer layer of vessels made of connective tissue
Do capillaries have all three layers
no they only have tunica intima
difference between arteries and veins
arteries have thicker walls, more resilient, high pressure, more smooth muscle, and smaller lumen while veins have larger diameter with a larger lumen, have valses, and depend on skeletal muscle to move blood, low pressure
elastic arteries
conducting, largest arteries and closest to the heart, highest pressure, expand and recoil in response to pressure.
Muscular arteries
distributing, medium size, thick muscle layer, distribute blood to specific organs.
elastic rebound
recoil of arteries at beginning of ventricular diastole
aneurysm
Swelling in the arterial wall due to localized weakness. Can burst causing hemorrhage.
atherosclerosis
plaques form as monocytes engulf cholesterol and become foam cells, they stick to endothelial cells and damage it, tissue overgrows, and platelets stick to the damaged wall.
capillary beds
cluster where capillaries are generally found
tissue perfusion
blood supply to a tissue through a capillary bed
precapilary sphincters
controls the amount of blood flowing into the capillaries. Each capillary-metarteriole junction contains one
metarterioles
small ateriole that feeds each capillary bed
thoroughfare channels
where metarterioles drain into.
Continuous capillaries
tight junctions that permit the diffusion of water, gases, small and lipid soluble molecules (skin and muscle tissue),
fenestrated capillaries
pores that permit the diffusion of larger molecules (kidneys, endocrine glands, small intestine)
sinusoids
discontinuous endothelium with large pores that permit very large molecules and blood cells (liver, bone marrow, spleen)
what do the valves of veins do?
extensions of the tunica intima that overlap and prevent backflow
where is most of the blood in the body at?
in the veins called venous reserve
what does the muscles and respiration do for blood movement?
both help propel blood along veins by squeezing the veins when muscles and lungs are contracted/larger in size