9: Vascular Histology

Question 1

Two factors formed by endothelium of the tunica intima

Answer 1

Von Willebrand factor + P selectin

Question 2

Von Willebrand factor vs p selectin functions

Answer 2

Von Willebrand: hemostasis

P selectin: inflammation

Question 3

Vasa vasorum and Nervi vasorum

Answer 3

Vasa vasorum: vessels that supply blood to vascular tunics themselves
Nervi vasorum: ANS input that controls contraction of vascular SM

Question 4

Metarterioles

Answer 4

First branch off arterioles to supply tissues

Question 5

Precapillary sphincter of metarterioles

Answer 5

Regulate blood flow through caps - when contracted they stop blood from flowing thru those capillaries; based on metabolic demand

Question 6

Thoroughfare channel of metarterioles

Answer 6

Distal end of metarteriole that connects to post-cap venule

Question 7

Pericytes

Answer 7

Perivascular contractile cells with branching cytoplasmic processes around capillaries

Question 8

What factor controls pericytes?

Answer 8

NO

Question 9

Three types of capillaries

Answer 9

Continuous: no gaps
Fenestrated: some gaps
Discontinuous: large gaps

Question 10

Tunics in veins vs arteries

Answer 10

Vein tunics not as well defined

Question 11

What layer of veins may contain valves?

Answer 11

Tunica intima

Question 12

Vein valves

Answer 12

Semilunar flaps of thin CT core + endothelium

Question 13

Three things that make veins different than arteries

Answer 13

1. Thinner walls
2. Larger lumen
3. Lumen often collapsed