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Control of peripheral circulation
N/A
43
Physiology
Graduate
01/15/2012

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Term
What are the systemic control mechanisms for blood distribution and blood pressure?
Definition
Neuronal (CNS and PNS) and hormal (endocrine system)
Term
What are the local control mechanisms for the regulation of blood distribution and blood pressure?
Definition
Lockally produced humoral factors and locally applied physical factors
Term
True or false: Local regulatory mechanisms can override systemic mechanisms for control of peripheral circulation
Definition
True
Term
The parameters in which a change in perfusions pressure results in an alteration of vascular resistance to maintain constant blood flow is known as what?
Definition
Autoregulatory range
Term
What is the function of autoregulation of circulation?
Definition
Maintenance of blood flow by responding to drops in perfusion pressure
Term
The contraction of vascular smooth muscle in response to an increase in transmural pressure (or the opposite in response to decreased transmural pressure) describes what?
Definition
Myogenic theory of autoregulation
Term
What are the function of endothelium-derived vasoactive substances?
Definition
Regulation of local blood flow
Term
Endothelium-derived vasoactive substances usually initiate what type of response regulating local blood flow?
Definition
Vasoconstriction
Term
Endothelium-derived vasoactive substances are usually released in response to what? What do they act on?
Definition
Pathological conditions, specific receptors or ion channels
Term
What endothelium-derived vasoactive substances are vasodilators?
Definition
Nitric oxide, prostacyclin (PGI2), mediated by ETB
Term
What endothelium-derived vasoactive substances are vasoconstrictors?
Definition
Endothelin, endothelin derived constriction factors 1 and 2 (EDCF1 and EDCF2), all mediated through ETA
Term
What is used to synthesize nitric oxide in endothelium?
Definition
L-arginine via nitric oxide synthase (NOS)
Term
What are the two forms of nitric oxide synthase (NOS)?
Definition
Constitutive (cNOS type III) and inducible (iNOS type II)
Term
What is the difference between constitutive and inducible nitric oxide synthase (NOS)?
Definition
Constitutive is Ca++ dependent and always produced, inducible is Ca++ independent and present during inflammation (in response to bacterial endotoxins and cytokines)
Term
What does nitric oxide activate in smooth muscle cells in order to stimulate relaxation?
Definition
Soluble cGMP
Term
How does cyclic GMP induce smooth muscle relaxation?
Definition
High cGMP inhibits calcium entry into the cell, activates K+ channels, stimulates cGMP-dependent protein kinase that activates myosin light chain phosphatase
Term
How does nitric oxide cause indirect vasodilation?
Definition
Inhibits vasoconstrictor influences such as angiotensin II and sympathetic vasoconstriction
Term
How does nitric oxide induce an anti-thrombotic effect?
Definition
Inhibites platelet adhesion to the vascular endothelium
Term
How does nitric oxide induce an anti-inflammatory effect?
Definition
Inhibits leukocyte adhesion to vascular endothelium, scavenges superoxide anions
Term
How does nitric oxide produce a anti-proliferative effect?
Definition
Inhibits smooth muscle hyperplasia
Term
An increase in organ blood flow associated with an increase in metabolic activity of the organ is known as what?
Definition
Active hyperemia
Term
Active hyperemia occurs due to what kinds of actions?
Definition
Increased skeletal muscle contractions, cardiac activity, brain activity, and GI activity following a meal
Term
A transient increase in organ flow that occurs following a brief period of ischemia, usually produced by temprorary arterial occlusion, describes what?
Definition
Reactive hyperemia
Term
The magnitude and duration of hyperemia are directly proportional to what? 
Definition
The magnitude and duration of the ischemia it follows
Term
Alpha-1 adrenergic receptors produce what kind of control over circulation?
Definition
Vasoconstriction
Term
Beta-2 adrenergic receptors produce what kind of control over circulation?
Definition
Vasodilation
Term
Beta-1 adrenergic receptors elicit what kind of control over circulation?
Definition
Effects heart rate and contractility
Term
Serotonin elicits what kind of control over circulation?
Definition
Vasoconstrictor for local control of tissue damage
Term
Theomboxane A2 elicits what kind of control over circulation?
Definition
Vasconstriction from platelets to promote platelet aggregation
Term
Histamines produce what kind of response in the cardiovascular system?
Definition
Vasodilator from mast cells in response to injury/inflammation, constricts bronchial smooth muscle
Term
What effect do prostaglandins have in the cardiovascular system?
Definition
Strong vasodilator
Term
What peptides provide neuro-humoral regulation of circulation by monitoring venous return and altering circulation volume?
Definition
Angiotensin II, atrial natriuetic peptide, vasopressin
Term
Does the opening of voltage-gated Ca++ channels produce vasocontraction or vasodilation?
Definition
Contraction
Term
Does the opening of voltage-gated Na+ channels produce vasocontraction or vasodilation?
Definition
Contraction
Term
Does the opening of voltage-gated K+ channels produce vasocontraction or vasodilation?
Definition
Vasodilation
Term
Does the activation of stretch-activated nonselective cation channels produce vasocontraction or vasodilation?
Definition
Contraction
Term
Do muscarinic receptors produce vasocontraction or vasodilation?
Definition
Vasocontraction
Term
What is used to elicit very rapid adjustments of blood pressure?
Definition
Vascular reflexes, mainly sympathetic nervous system via innervation of arteries, arterioles, and veins
Term
Are capacitance vessels (veins) more responsive to sympathetic stimulation or vasodilator metabolites?
Definition
Sympathetic stimulation
Term
How is sympathetic stimulation to aide in cardiovascular demands during exercise?
Definition
Constricts veins and augments the cardiac filling
Term
Baroreceptors found in the carotid sinus send signals across which nerve to the CNS?
Definition
Glossopharyngeal nerve
Term

Baroreceptors found in the aortic arch send signals across which nerve to the CNS?

Definition
Vagus nerve
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