092414 vascular system Flashcards Preview

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Flashcards in 092414 vascular system Deck (29):
1

what is the progression of vasculature from the heart?

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

2

role of the vascular system

maintain QUALITY and VOLUME of extracellular fluid

3

blood vessel walls have 3 layers. what are they?

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.

4

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

arterial side

5

describe the layers of heart tissue

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.

6

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

fibroblasts

7

what do epicardial cells give rise to?

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

8

features of large thick arteries

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.

9

fxn of elastic arteries

elastic recoil to maintain BP during diastole

10

which layer is thickest in large veins?

adventitia

11

how are medium vessels diff from large arteries?

the media has less elastin

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

12

how many layers of sm musc cells do medium vessels have

40

13

fxn of medium vessels

regulate BP

14

how does atherosclerosis develop?

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)

15

what are foam cells?

macrophages
smooth muscle cells that move to the intima

16

diff btwn medium artery and medium vein

artery has a lot more tunica media

17

layers of sm muscle in small artery and arteriole?

8 and 2, respectively

18

fxn of small arteries and arterioles

the smooth muscle cells regulate blood flow to capillary bed

19

how do small vessels play a role in HTN?

lipid uptake by smooth muscle cells narrows the lumen

20

diameter of a capillary

7.5 micrometers = 1 RBC

21

3 different types of capillaries

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.

22

pinocytotic vesicles are not present in capillaries where?

CNS

23

ex of places with continuous capillaries

CNS
heart
skel musc
lung

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

24

sites with fenestrated capillaries

endocrine glands
GI tract
kidneys

to transport hormones, nutrients, ions

25

sites with sinusoidal cpillaries

bone marrow
spleen
liver

to transport whole cells

26

how do capillaries transport nutrients

through pinocytotic vesicles, fenestrations, discontinuities

27

fxns of endothelial cells

exchange gases and nutrients

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

28

how does angiogenesis begin?

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

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

29

bevacizumab (avastin)

anti-VEGF monoclonal antibody used to treat tumors