Unit 4 - Vasculature: Overview and Arteries Flashcards
Generally, what are the layers of a blood vessel?
tunica intima/interna, tunica media, tunica adventitia/externa
What are the layers of the tunica intima/interna?
Endothelium and internal elastic membrane
What is contained in the endothelium of the tunica intima/interna?
A basal laminal layer, and a subendothelial layer
What is the subendothelial layer of the endothelial layer of the tunica intima/interna made out of?
collagen and elastic fibers, fibroblasts, and smooth muscle in some vessels
What is the internal elastic made of and what is its functional significance?
it is a sheet of elastin with gaps that permit nutrient diffusion into the tunica media
What is the tunica media made out of?
elastic and smooth muscle fibers with an external elastic membrane
Where do the elastic and smooth muscle fibers of the tunica media receive their nutrients from?
from the tunica interna, and vasa vasorum
What is vaso vasorum?
the blood vessel for a blood vessel
What is the tunica adventiti/externa made out of?
Connective tissue, vaso vasorum, and nervi vasorum
Rate large arteries, medium/small arteries, and arterioles from high to low levels of elastin.
Arteries > medium/small arteries > arterioles
Rate large arteries, medium/small arteries, and arterioles from high to low levels of smooth muscle.
Arterioles > medium/small arteries > arteries (no smooth muscle)
Rate large arteries, medium/small arteries, and arterioles from high to low levels of vascular resistance.
Arterioles > medium/small arteries > arteries
Do arterioles or veins have more muscle cells?
arterioles
Do large veins or venules have more layers of muscle cells?
large veins
What is the composition of the interna layer of elastic arteries?
thicker than other arteries, brick-like endothelial cells, internal elastic membrane has splits into lamellae that may merge with the tunica media
What is the composition of the media layer of elastic arteries?
thickest of the tunics, fenestrated and concentrically arranged elastic laminae
What is the composition of the externa layer of elastic arteries?
Longitudinal/interlaced collagen fibers, few elastic fibers/FBs
What is the functional significance of elastic arteries?
the elasticity of the large arteries allows them to recoil and maintain high pressure during diastole
What is the composition of the interna layer of the muscular arteries?
thin subendothelial layer with a thick internal elastic membrane that has fenestrations
What is the composition of the media layer of the muscular arteries?
thick, mainly smooth muscle and discontinuous external elastic membrane
What is the composition of the externa layer of the muscular arteries?
collagen, fibroblasts, elastic fibers
What is the structural difference between arteries and veins?
Arteries have thicker elastic muscular walls than veins compared to lumen size and veins have thinner walls with valves in the tunica interna, and few muscles cells in the tunica media
What is the functional difference between arteries and veins?
arteries carry oxygenated blood in systemic circulation and veins carry deoxygenated blood in venous circulation The exception is pulmonary circulation - arteries and veins have opposite functions than normal
What is the structure of an arteriole?
endothelium with a subendothelial connective tissue layer and an internal elastic membrane, there is no external elastic membrane, the tunica externa is made of loose connective tissue
