B4.020 - Cell Bio and Histology of Vascular System

Question 1

what do pericytes do in the capillaries

Answer 1

these cells allow endothelial cells to multiply and form branches, processes critical for blood vessel growth and repair

Question 2

what is a key mediator of vessel growth

Answer 2

hypoxia

Question 3

what type of vessel is this

Answer 3

fenestrated capillary

Question 4

what allows for continuous capillaries to transport anionic proteins out of blood stream

Answer 4

plasmalemmal vesicles are neutrally charged allowing for transcytosis

caveolae are coated with cytoplasmic surfaces in protein, caveolin

Question 5

what are capillaries

Answer 5

thin tubes consisting only of endothelial cells and their basement membranes. Small diameter permitting passage of 1 RBC at a time

Question 6

identify the structures with arrows

Answer 6

Question 7

describe the 3 tunics of veins

Answer 7

distinction between t media and t adventitia often unclear and a distinct internal elastic lamina is usually absent

T media is thinner than that found in arteries of same diameter

Question 8

in the case of chronic cell injury what to pericytes do

Answer 8

dedifferentiate into myofibroblast like cells, which are responsible for overproduction of ECM that can lead to fibrosis

Question 9

how do large elastic arteries sustain continuous blood flow despite intermittend pumping of heart

Answer 9

their walls ditend during systole and recoil during diastole

Question 10

what is vasculogenesis

Answer 10

creation of a new vascular network

Question 11

describe tunica externa

Answer 11

connective tissue (large vessels have vasa vasorum, neural tissue)

Question 12

what is the arrow pointing to

Answer 12

arteriole

Question 13

identify the 3 types of capillaries

Answer 13

1. continous
2. fenestrated
3. discontinuous

Question 14

what are the arrows pointing to

Answer 14

Question 15

describe blood pressure and vascular anatomy

Answer 15

Question 16

what are caveolae

Answer 16

found in continuous capillaries

help with transport of substances through the cytoplasm in bidirectional pathway (transcytosis)

Question 17

describe medium sized arteries

Answer 17

muscular arteries

compared with elastic arteries, often see a prominent internal elastic lamina. Also in tunica media there are a fewer elastic sheaths but more prevalent smooth muscle fibers. An external elastic lamina also commonly seen

Question 18

what type of blood vessel is this

Answer 18

medium artery

Question 19

how do veins prevent reflux of blood

Answer 19

they have valves

Question 20

what is an atheroma

Answer 20

when lipids are taken up by macrophages in the tunica intima and fibroblasts of the subendothelial space proliferates

macrophages produce IL-1 and TNF alpha to recruit leukocytees into the atheroma space.

Question 21

what is angiogenesis

Answer 21

sprouting from an existing network

Question 22

what are pericytes

Answer 22

contractile cells surrounding some capillaries and post cap venules thought to regulate blood flow.

Question 23

how does hypoxia lead to vessel growth

Answer 23

Question 24

what are these

Answer 24

fenestrae with diaphragms

Question 25

what vessel type regulates the distribution of blood to different capillary beds by vasoconstriction and vasodilation

Answer 25

resistance vessels - arterioles

Question 26

what are HIF target genes

Answer 26

VEGF VEGFRs EPO GLUT

Question 27

what are the arrows pointing to

Answer 27

thin discontinuous basement membranes

Question 28

what are things to look for to identify arteries from veins

Answer 28

arteries are symmetric, veins are not arteries have more smooth muscle layers

Question 29

Answer 29

Question 30

what are the arrows pointing to

Answer 30

top 2 arterioles bottom - lymph vessel

Question 31

describe tunica media

Answer 31

concentric layers of smooth muslce, collagen fibers. discontinuous plates of elastic sheaths

Question 32

what are discontinuous capillaries

Answer 32

have overt gaps between endothelial cells

Question 33

where is the preferred site of leukocyte egress from blood across vessel walls

Answer 33

veins, post capillary venule

Question 34

identify the type of capillary

Answer 34

continuous

Question 35

what are the arrows pointing to

Answer 35

lemphatic vessel with valve

Question 36

identify the type of capillary

Answer 36

fenestrated

Question 37

what is depicted here

Answer 37

caveolae

Question 38

what can loss of pericytes cause

Answer 38

if lost in CNS increase permeability of blood brain barrier and contributes to neurodegenerative disease

Question 39

what is this

Answer 39

fenestrae without diaphragms

Question 40

describe tumor angiogenesis

Answer 40

tumors that get larger requires more oxygen and secretes agiogenic factors that stimulate migration, proliferation, neovessel formation by endothelial cells

Question 41

what type of blood vessel is this

Answer 41

large elastic artery

Question 42

what is depicted here

Answer 42

diapedesis

Question 43

where are discontinuous capillaries found

Answer 43

liver, spleen, bone marrow

Question 44

where are fenestrated capillaries found

Answer 44

sites of fluid transport Intestine kidney

Question 45

what types of plasma proteins are present in plasma

Answer 45

albumin (70%) gamma globunins (Abs) fibrinogen

Question 46

identify the type of capillary

Answer 46

discontinuous

Question 47

describe the tunica intima

Answer 47

lining of endothelial cells, subendothelial basement membrane and loose connective tissue, dense layer of elastic fibers

Question 48

where are continuous capillaries found

Answer 48

muslce, brain, thymus, lungs areas where gas exchange is tightly regulated

Question 49

what are the 3 types of capillaries

Answer 49

continuous fenestrated discontinuous

Question 50

what are the resistance vessels

Answer 50

arterioles

Question 51

what are fenestrated capillaries

Answer 51

have pores or fenestrae in endothelium

Question 52

what do vasculogenesis and angiogenesis both require

Answer 52

VEGF

Question 53

what is the triangle and arrow pointing to

Answer 53

triangle - pericyte arrow - venule

Question 54

what are continuous capillaries

Answer 54

Capillaries with no overt gaps or fenestrae. Pericytes (modified smooth muslce cells) can occur between endothelium and basement membrane

Question 55

major blood vessels

Answer 55

large elastic artery medium muscular artery small artery arteriole capillary venule medium and large veins