Vasculature Flashcards
Basic layers of blood vessel walls
- how do they line the vessel
- what do they comprise of?
(Skim/familiarize self w. this. More details in later cards)
- Tunica intima
- inner layer closest to lumen
- may comprise of endothelial cells, elastic laminae, loose collagenous tissue, fibroblasts, MYOINTIMAL cells - Tunica media
- middle layer
- may comprise of mult. layers of elastic laminae, sm, collagen - Tunica adventitia
- thick sum’bitch outer layer
- made of collagenous tissue
Myointimal cells
found in intima layer of elastic arteries
similar structural feature to smooth muscle (sm)
Arteries
- Thicker than veins
- Lumen and wall thickness ~ equal
- Large A
- Thick media
- Multiple elastic + sm layers (esp. closer to heart for expansion +contraction)
Different types of arteries
- Elastic arteries
- large - Muscular arteries
- medium - Small muscular arteries
- small
Elastic arteries
-Layers and what they contain
aorta/large arteries
Intima:
endothelial cells, fibroblasts, myointimal cells
Media:
multiple elastic layers
collagenous fibers and sm sandwiched between the layers
adventitia:
vasa vasorum
Vasa vasorum
vessels of vessels
Found in adventitia in large Arteries and large Veins
- supplies oxygen/nutrients to adventitia/outer media,
since blood vessels inside are too lazy to reach it
Muscular artery layers
Layers:
Thin endothelial/connective tissue Intima --> Inner elastic lamina --> Smooth muscle Media --> Outer elastic lamina --> Collagen/elastin Adventitia
(note that there are only 2 elastic layers vs the multiple we see in elastic)
Smaller muscular artery layers
Layers: Thin endothelial cell/collagenous Intima --> Inner elastic lamina --> Smooth muscle Media --> Adventia that blends with surrounding CT
Blood pressure control is at the level of what?
the smooth muscle in the vessels
Arteriole layers
Layers: Endothelium --> Thin basement membrane --> Smooth muscle --> Outer collagenous tissue that blends with surrounding CT
(arterioles are the “gate keepers” for capillaries)
Two ways that arterioles can direct blood flow
- Metarteriole shunt
- controls flow of a. blood directly into capillary bed - Arteriole-Venule shunt:
- shunts blood away from capillary bed, connect larger arterioles and venules, therefore, bypassing capillary beds
Capillaries
Layers
Endothelium –> pericytes –> collagenous fibrils (connects cap to adj. CT)
( no muscular layer)
Pericytes
give rise to smooth muscle cells during vessel growth and wound healing
Two types of capillaries
-how do they transfer material differently?
- continuous: via pinocytosis
- no free flow of blood - fenestrated: via pores
(ie: kidney glomerulus / liver sinusoids)
- free flow
Post capillary venule
-physical features
Slightly larger diameter than capillaries.
Layers:
endothelium –> pericytes –> (if large) smooth muscle media –> thin connective adventitia
