Control of Tissue Blood Flow Flashcards

1
Q

What organs have alpha-1 receptors?

A

GI, skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What organs have beta-2 receptors?

A

skeletal & coronary arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What kind of receptors do cerebral arteries have?

A

THEY DO NOT RESPOND TO NEURAL/ENDOCRINE CONTROL. only local.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What contribution does the PNS make to neural control of tissue blood flow?

A

Vasodilation & secretion of the salivary gland through VIP & ACh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What compounds have effects as hormones to control tissue blood flow?

A

1) epinephrine
2) AngII
3) ADH/Vasopressin
4) Bradykinin
5) Histamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does AngII affect tissue blood flow?

A

directly causes smooth muscle vasoconstriction

–> increase TPR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does ADH affect tissue blood flow?

A

causes vasoconstriction & water/salt retention

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does bradykinin affect tissue blood flow?

A

causes vasodilation & increased capillary permeability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does histamine affect tissue blood flow?

A

vasodilation & increased capillary permeability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What cells release histamine?

A

mast cells & basophils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

where are mast cell located?

A

tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

where are basophils located?

A

blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How bradykinin activated?

A

1) lysis/inflammation –> kallikrein activation
2) kallikrein: a2-globulin –>kallidin
3) kallidin –> bradykinin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is bradykinin inactivated?

A

carboxypeptidase or ACE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the two theories for local control of tissue blood flow?

A

1) vasodilator

2) nutrient/o2-lacking theory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the vasodilator theory of local control?

A

increased metabolism –> vasodilator production

vasodilators: adenosine, histamine, H+, CO2

17
Q

Describe the nutrient/O2 lacking theory.

A

1) Decreased flow –> O2/nutrient depletion

2) inability of vessels to contract, so they relax

18
Q

Define autoregulation.

A

acute increase in P will increase Q, but Q returns to normal within a range of P’s

19
Q

What are the 2 theories for autoregulation?

A

Metabolic & Myogenic

20
Q

Describe the myogenic theory for autoregulation.

A

Vascular smooth muscle contracts due to stress-activated channels

21
Q

Describe the metabolic theory for autoregulation.

A

Increased o2 + nutrients –> contraction

22
Q

When is endothelin released?

A

endothelium releases endothelIN due to damage to prevent blood loss

23
Q

What are the consequences of endothelin in HTN?

A

may cause additional vasoconstriction

24
Q

How are endothelin receptors used in drug therapy?

A

endothelin receptor antagonists for pulmonary HTN

25
What is the primary form of regulation for cerebral arteries?
local control
26
How does local regulation play into the overall regulation in cardiac & skeletal muscle?
local can override SNS in cardiac/skeletal muscle.
27
What are other effects of EDRF / NO?
1) inhibition of leukocyte adhesion (infection) 2) inhibition of platelet adhesion (thrombus) 3) inhibition of vascular smooth muscle proliferation (atherosclerosis)
28
How is eNOS activated?
shear stress activation of clarithrin receptor
29
What reaction does eNOS catalyze?
O2 + L-arginine --> NO + L-citrulline
30
How does NO promote vascular relaxation?
1) NO diffuses to smooth muscle, activates soluble guanylate cyclase 2) SGC: GTP --> cGMP to activate PKG cGMP promotes relaxation
31
How is cGMP inactivated?
Phosphodiesterases
32
How is Viagra used to promote vascular relaxation?
prevents PDE-5 from inactivating cGMP
33
How is the need for neovascularization determined?
determined by MAX (not average) required blood flow to overcome a given hypoxia
34
How do tumor cells promote vascularization?
1) tumor cells release signal to cause change in cell type 2) perivascular cells detach & remodel 3) angiogenic/inflammatory stimuli attract other cells - - platelets, endothelial progenitor cells, myeloid cells
35
Why does angiogenesis continue in a neoplasia?
Tumor angiogenesis does not improve hypoxic environment. Vessels are leaky & tumor is poorly perfused