lecture 12/13: Histology of CV System (Baekey) Flashcards
Where is number of vessels and cross sectional area greatest?
capillaries
where is most blood volume?
veins
What kind of vessel has the most elastic tissue?
large arteries
in which vessels is elastic tissue absent?
capillaries, venules
Table p. iii on Histo section in SCAVMA
:)
how do blood vessels develop?
vacuole fusion
how are endothelial cells joined?
intercellular junctions
Components of tunica intima in elastic arteries (3)
endothelium, subendothelium, internal elastic membrane
Components of tunica media in elastic arteries (3)
smooth muscle, elastic fibers, collagenous fibers
Components of tunica externa in elastic arteries (3)
collagenous fibers, nervi vasorum, vasa vasorum
vasa vasorum
network of small blood vessels that supply large blood vessels (“vessels of the vessels”)
Difference b/w elastic and muscular arteries
exactly the same, except muscular arteries do not have collagenous fibers
Pericytes
aka pericapillary cells.Wrap around fenestrated capillaries to keep proteins in the capillaries and let fluid through (regulate permeability through capillary to help create urine)
How is blood flow regulated through capillaries?
precapillary sphincters of arteriole control flow into capillary bed proper. Anteriolar-venous anastomoses connect terminal arteriole directly with a venule
continuous capillary and found where?
tight junctions between endothelial cells. Found in muscle, lungs, nervous system
fenestrated capillaries are found where?
pores present in endothelial cells and basal lamina. Found in endocrine glands, intestine, kidneys
Sinusoidal capillaries and where found?
large diameter and gaps. Basal lamina diminished or absent. Found in liver, spleen, bone marrow
Tunica media and intima in veins vs. arteries
veins have less developed/thinner tunica intima and media than arteries
venules
Formed where several capillaries meet. May form portal systems b/w two capillary networks (i.e. hepatic)
tunica intima of veins contains (3)
endothelium, thin subendothelium, valves
tunica media of veins contains
limited muscle and elastic fibers
tunica externa of veins contains
collagenous fibers
Endocardium in heart includes: (3)
endothelium, subendothelial coat, subendocardial coat. Analogous to tunica intima
Myocardium in heart =
cardiac muscle
epicardium in heart includes (2)
subepicardial coat, serous mesothelium
between which layers are purkinje fibers located
endocardium and myocardium
epicardium =
visceral pericardium
annuli fibrosi
fibrous rings that surround each of the heart valves in bovine. Continuous with the connective tissue of the valve
ossa cordis
bone formation around aortic valve in bovine
trigonum fibrosum
fibrous triangle b/w AV canals in dogs
lymph capillary vs. capillary
lymph capillaries have little or no basal lamina (makes them more permeable). Also have anchoring microvilli
Lymph vessel vs. vein
thinner walled, irregularly shaped, tunics not well defined
what kind of artery is aorta?
elastic artery
where is external elastic membrane located?
between tunica externa and tunica media
Veins have ______ band of internal elastic membrane, while arteries have ______ band of internal elastic membrane
discontinuous; continuous
What structures are present in connective tissue between artery and veins?
nervi vasorum, vasa vasorum, arterioles, capillaries
What kind of cells are glands (i.e. bile duct) surrounded by?
cuboidal
glomerular capillaries =
fenestrated capillaries
podocyte
a specialized pericyte in the glomerulus of the kidney. Wrap around fenestrated capillaries to keep proteins in the capillaries and let fluid through (regulate permeability through capillary to help create urine)
mesangial cells
form the “glue” that holds fenestrated capillaries in a ball within glomerulus
sinusoidal capillary diameter compared to continuous and fenestrated capillaries
larger
portal triad contains
bile duct + artery + vein
what makes up skeleton of valves?
hyaline cartilage. Stains purple/blue
