092414 vascular system

Question 1

what is the progression of vasculature from the heart?

Answer 1

elastic arteries to muscular arteries to small arteries/arterioles to capillary bed

capillary bed to post-capillary venules to venules to medium veins to large veins

Question 2

role of the vascular system

Answer 2

maintain QUALITY and VOLUME of extracellular fluid

Question 3

blood vessel walls have 3 layers. what are they?

Answer 3

tunica adventitia-outer. connective tissue.

tunica media-the most variable. smooth muscle cells and connective tissue.

tunica intima-inner. endothelium. endothelial cells. simple squamous with basal lamina.

Question 4

where are smooth muscle cells of the tunica media most prominent in the vascular system?

Answer 4

arterial side

Question 5

describe the layers of heart tissue

Answer 5

intima-endocardium.
simple squamous endothelium with basal lamina

media-myocardium.
consists of myocytes and fibroblasts. attaches to dense connec tissue skeleton.

adventitia-epicardium.
simple squamous. also known as visceral pericardium.

Question 6

what cells are the predominating type in the tunica media of the heart?

Answer 6

fibroblasts

Question 7

what do epicardial cells give rise to?

Answer 7

cardiac fibroblasts
coronary arteries (endothelial cells, smooth muscle cells)
cardiac myocytes possibly

Question 8

features of large thick arteries

Answer 8

external elastic membrane in adventitia

media is the thickest. has circular smooth muscle cells interdigitating with 40-70 elastic lamellae

intimia endothelial cells have tight jxns and pinocytotic vesicles. pinocytotic vesicles are for nutrient exchange.

Question 9

fxn of elastic arteries

Answer 9

elastic recoil to maintain BP during diastole

Question 10

which layer is thickest in large veins?

Answer 10

adventitia

Question 11

how are medium vessels diff from large arteries?

Answer 11

the media has less elastin

the intima has internal elastic lamina, which is a marker for medium vessels

Question 12

how many layers of sm musc cells do medium vessels have

Answer 12

40

Question 13

fxn of medium vessels

Answer 13

regulate BP

Question 14

how does atherosclerosis develop?

Answer 14

intimal plaques derived from foam cells, which take up LDL (for ex, macrophages ingest LDL. and smooth musc cells move to the intima and ingest LDL)

Question 15

what are foam cells?

Answer 15

macrophages

smooth muscle cells that move to the intima

Question 16

diff btwn medium artery and medium vein

Answer 16

artery has a lot more tunica media

Question 17

layers of sm muscle in small artery and arteriole?

Answer 17

8 and 2, respectively

Question 18

fxn of small arteries and arterioles

Answer 18

the smooth muscle cells regulate blood flow to capillary bed

Question 19

how do small vessels play a role in HTN?

Answer 19

lipid uptake by smooth muscle cells narrows the lumen

Question 20

diameter of a capillary

Answer 20

7.5 micrometers = 1 RBC

Question 21

3 different types of capillaries

Answer 21

type I-continuous:
tight jxns admit proteins only smaller than 10 kDa
pinocytotic vesicles allow passage of larger proteins

type II: fenestrated
100 nm windows, which are permanenet pinocytotic vesicles

type III: sinusoidal
discontinuities
these capillaries are larger in diameter than types I and II. the diameter is about 30 micrometers.

Question 22

pinocytotic vesicles are not present in capillaries where?

Answer 22

CNS

Question 23

ex of places with continuous capillaries

Answer 23

CNS
heart
skel musc
lung

basically-sites where the major thing you want to transport is oxygen

Question 24

sites with fenestrated capillaries

Answer 24

endocrine glands
GI tract
kidneys

to transport hormones, nutrients, ions

Question 25

sites with sinusoidal cpillaries

Answer 25

bone marrow
spleen
liver

to transport whole cells

Question 26

how do capillaries transport nutrients

Answer 26

through pinocytotic vesicles, fenestrations, discontinuities

Question 27

fxns of endothelial cells

Answer 27

exchange gases and nutrients

secrete regulatory molecules (vasoactive factors; growth factors like FGF, PDGF, VEGF)

Question 28

how does angiogenesis begin?

Answer 28

by targeting endothelial cell receptors like VEGFR, FGFR, TIE-2

the ligands for the above receptors are VEGF, FGF, and angiopoietin-1

Question 29

bevacizumab (avastin)

Answer 29

anti-VEGF monoclonal antibody used to treat tumors