Vasculature I Flashcards
3 layers of blood vessels from innermost to outermost
intima, media, and adventitia
4 layers of the tunica intima from innermost to outermost
endothelium, basal lamina subendothelial CT, internal elastic membrane
Endothelium of tunica intima
direct contact with blood. Has epithelial layer w/ simple squamous cells, and endothelium that is connected to basal lamina
Subendothelial connective tissue
ECM+ cells to synthesize that matrix. Can have smooth muscle cells that invade here
Internal elastic membrane
fenestrated. Important for movement of gas and nutrients
Tunica media
made mostly of smooth muscle cells
Tunica aventitia
blood vessels and nerve fibers transmitted in this layer.
Vasa vasorum
vessels of the vessels. Contribute to inflammation
Syphilis
tree bark appearance of ascending aorta. Fibrous scar in media. Endartertitis of vasa vasorum
Nervi vasocum (bascularis)
nerves that supply blood vessel walls. Mostly sympathetics, but some parasympahetic. Don’t penetrate tunica media.
Endothelial cells
flattened. Oriented in direction of blood flow. Elongated in direction of flow. Has pinocytotic vesciles
What does shear stress exerted by blood flow produce
endothelial cell hyperpolarization. Results in vasodilation
Pinocytotic vesciles
transport from lumen of blood vessel across cytoplasm to be released on subendothelial tissue compartment of tunica intima
Weibel-Palade granules
contain von willebrand factor. and P-selectin
Von Willebrand factor
important for coagulation. Deficiency results in hemorrhagic diseases
P-selectin
important for allowing leukocytes to connect to endothelial cell membrane and facilitate migration through wall of vasculature
Yellow endothelial cell functions
produce prostacylin, chemical mediation, Control vascular growth, inhibit blood clot or promote clot formation, regulate movement of inflammatory cell from blood lumen into tissues
Prostacyclin
vasodilator controlling diameter or vessel. increases flow, inhibits blood clotting.
What is different about vessels involved in microcirculation
no extra tunics to interrupt exchange of gas and nutrients. thin component
What’s different about veins as they go from larger to smaller
not much change in smooth muscle from small to large vessels, pick up elastic components
Architercture of artery
prominent elastic membrane. Thick muscular tunica media
Architecture of vein
do not have prominent internal or external lamina, think tunica media, tunica adventitia has lot of CT
Elastic artery
ex) aorta, brachiochephalic trunk
Tunica media has alternating smooth muscle and elastic lamellae that are fenestrated
Marfan’s syndrome
dysfunctional elastic arteries
Aorta
changes over a life time. Thicker in adult vs a newborn. Intimal fibrosis, fragmentation of elastic lamellae
Differences in muscular artery
lots of smooth muscle in tunica media, demonstrable externa elastic membrane, collagen in tunica adventitia is brunt orange
Function of arteriole
main resistance
How to tell it’s an ateriole
blue dots of endothelial cell nuclei
one or two smooth muscle layers
thin external adventitia
How to tell if it’s a venule
one layer of smooth muscle
white outline is the basal lamina
thinner wall and larger lumen compared to arteriole
Sphincter mechanism on metarteriole
controls bolume of blood flow to arteriole to microciculation
What are the 3 classes of capillaires
continuous
fenestrated
sinusoid
2 subclasses of fenestrated capillary
with diaphragms
sans diaphragms
Pericyte
associated with capillaries and pericytic venules
has mesenchymal cells
contractile
can differentiate into either smooth muscle cells or fibroblasts
