Vascular Biology

Question 1

As arteries get smaller the velocity increases/decreases.

Answer 1

decreases –> cross sectional area –> promotes nutrient exchange

Question 2

The amount of work that must be done to overcome friction between adjacent layers of fluid sliding over each other

Answer 2

shear force

Question 3

Dilation of blood vessel after a period of ischemia is called:

Answer 3

hyperemia

Question 4

Arteries that carry blood from the aorta to branch arteries

Answer 4

conduit arteries

Question 5

Arterioles vasoconstrict/vasodilate in response to ischemia

Answer 5

vasodilate

Question 6

Do large conduit arteries vasodilate to ischemia?

Answer 6

yes: 12-15%

Question 7

4 molecules that promote vasodilation

Answer 7

NO/EDRF, prostacyclin (PGI2), bradykinin, acetylcholine

Question 8

How does NO lead to vasodilation?

Answer 8

L-arginine is involved in production of eNOS (endothelial NO synthase) –> NO diffuses into smooth muscle cell –> activation of cGMP

Question 9

How does Ach, substance P, bradykinin, B2 agonists lead to vasodilation?

Answer 9

G protein calmodulin pathway –> production of eNOS –> NO diffusion to smooth muscle cell –> cGMP

Question 10

2 effects of ACh on blood vessels

Answer 10

1. stimulates release of NO from endothelium leading to vasodilation
2. vasoconstriction/contraction in circumstances with low NO (e.g. damaged endothelium) or with high doses of ACh (even low levels of ACh can cause constriction in diseased arteries)

Question 11

High ACh + low NO causes vasoconstriction/dilation

Answer 11

vasoconstriction

Question 12

Which is more potent? NO or PGI2

Answer 12

NO

Question 13

Angiotensin is a vasoconstrictor/dilator

Answer 13

constrictor –> breaks down bradykinin thereby preventing vasodilation by reducing production of NO and and PGI2

Question 14

A high fat diet impairs endothelial mediated vasodilation/vasoconstriction for up to four hours after eating.

Answer 14

vasodilation

Question 15

What is the difference between an angioblast and an endothelial progenitor cell?

Answer 15

angioblast is in utero and epc is what is modified during adulthood to create new vessels –> all under control of VEGF

Question 16

What factors stabilize growing blood vessels?

Answer 16

angiopoetin 1 and ephrin b2

Question 17

What are 3 important growth factors for vessels?

Answer 17

pdgf, tgf beta, fgf

Question 18

What growth factor can destabilize growing vessels leading to possible tumorigenesis?

Answer 18

angiopoetin 2

Question 19

EPCs from patients with type II diabetes mellitus are characterized by:

Answer 19

decreased proliferation capacity and reduction of their adhesiveness and ability to form capillary tubes in vitro

Question 20

What autosomal dominant condition can result from disruption of TGF beta signalling via abnormalities in one of two genes, endoglin (Eng) and activin-receptor-like kinase-1
(ALK1)?

Answer 20

HHT/Osler-Weber-Rendu

Question 21

4 consequences of HHT

Answer 21

1. GI bleeding
2. infection from septic emboli
3. arteriovenous malformation in lungs causing shunting of blood and paradoxical emboli
4. telangiectases

Question 22

3 classifications of anti-clot systems

Answer 22

1. fibrinolytic - t-PA
2. antithrombin - thrombomodulin, heparin
3. antiplatelet - NO, prostacyclin, ADPases

Question 23

2 classifications of pro-clot systems

Answer 23

1. anti-fibrinolytic - PAI1

2. angiotensin II stimulation of PAI1 (plasminogen activator inhibitor)

Question 24

_____ cleaves fibrin to produce progressively smaller degradation products

Answer 24

Plasmin

Question 25

Virchow's triad

Answer 25

hypercoagulable state, endothelial injury, circulatory stasis --> clotting/DVT

Question 26

2 procoagulable properties of dysfunctional endothelium leading

Answer 26

1. increase vwf production with increased platelet adhesion/aggregation 2. increased synthesis of PAI1 resulting in impaired fibrinolysis

Question 27

All cell adhesion molecules are constitutively expressed on endothelium except:

Answer 27

ICAM II

Question 28

Migration of neutrophils, monocytes and lymphocytes from the circulating blood to the inflammatory sites is directed by the expression of specific _____ on the endothelium

Answer 28

cell adhesion molecules

Question 29

______ is a transcription factor involved in the expression of genes encoding many proinflammatory functions of vascular wall cells and infiltrating leukocytes.

Answer 29

NFkB

Question 30

_________ acts as a proinflammatory factor by stimulating NFkB leading to expression of _____, which mediates monocyte adhesion and of the chemokine _____, which attracts monocytes

Answer 30

Angiotensin-II, VCAM-1, MCP-1

Question 31

Angiotensin-II stimulates expression of | ______, which provokes the acute-phase response leading to production of the systemic inflammatory marker _________..

Answer 31

interleukin (IL)-6, C-reactive protein | CRP

Question 32

Studies in hypercholesterolemic rabbits have | shown that ____ localizes in endothelium over foam cell–filled fatty streaks in the aorta.

Answer 32

VCAM

Question 33

T/F Endothelial leukocyte adhesion molecules play an important role in early plaque development

Answer 33

T

Question 34

____ stimulates production of endothelial | leukocyte adhesion molecules early in atherosclerotic lesion formation

Answer 34

OxLDL aka oxidative fat

Question 35

Spiral secondary flows and recirculation zones with lower shear stress result in round/elongated endothelial cells

Answer 35

round

Question 36

Do blood vessels have cholinergic innervation?

Answer 36

no --> only muscarinic receptors

Question 37

What stimulates NOS to produce NO from L-arginine?

Answer 37

shear stress, chemical mediateors like ACh

Question 38

Name a competitive inhibitor of L-arginine that indirectly inhibits NO production

Answer 38

ADMA

Question 39

What stimulates PGI2 release from endothelium?

Answer 39

shear stress, physiologic agonists, pathologic insult --> inhibits platelet activation, secretion, aggregation and maintains relaxation

Question 40

Vasoconstrictor or vasodilator? TxA2

Answer 40

constrictor

Question 41

Vasoconstrictor or vasodilator? PGI2

Answer 41

dilator

Question 42

Vasoconstrictor or vasodilator? NO

Answer 42

dilator

Question 43

Vasoconstrictor or vasodilator? endothelin

Answer 43

constrictor

Question 44

Vasoconstrictor or vasodilator? ACh

Answer 44

constrictor

Question 45

Vasoconstrictor or vasodilator? Angiotensin II

Answer 45

constrictor

Question 46

Vasoconstrictor or vasodilator? bradykinin

Answer 46

dilator

Question 47

Vasoconstrictor or vasodilator? substance P

Answer 47

dilator

Question 48

Vasoconstrictor or vasodilator? superoxide anion O2-

Answer 48

constrictor

Question 49

What happens to the number of EPCs in patients with risk factors for ischemic cardiovascular disease?

Answer 49

reduce number of endothelial preogenitors