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27 Cards in this Set
- Front
- Back
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α2-receptors are located where?
action? |
* pre-synaptic nerve endings
* post-synaptically on beta cells of pancreas * inhibitory |
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on post-synaptic membrane of the effector organ
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α1-receptors
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Equal affinity for epinephrine and nor-epinephrine
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β1-receptors
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Where are β1-receptors located?
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Heart, juxta glomerular apparatus of kidney, fat cells
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When epinephrine binds β1-receptors, what effect does it have on heart rate?
On contractability? On cardiac output? |
* Increased
* Increased * Increased |
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When NORepinephrine binds β1-receptors, what effect does it have on (1) heart rate?
(2) On contractability? (3) On cardiac output? |
(1) decreased HR
(2) increased contractability (+ ionotrophic) (3) incr. cardiac output |
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Where are β2-receptors located?
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β2-receptors locations:
Blood vessels of SK. muscle, liver for glycogenesis*, smooth muscles of <<bronchus>>, urogenital tract system and uterus* and CORONARY ARTERY * only places stimulation happen (not relax/inhibition) w/β2 |
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Which receptor is activated through G-protein activation of phopholipase C?
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α1-receptors
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When α2 receptors are stimulated what happens?
Exceptions? Where? (4) |
Causes feedback INHIBITION of release of norepinephrine
Generally promotes SEDATION, but in uterus (when bound by NE) and in blood vessels of skin, mucosa, splanchnic, renal - it promotes constriction. |
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Receptors on blood vessels of skin and kidney and splanchnic area?
Epinephrine causes ? NE causes? |
α1, α2
Constriction Constriction |
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Receptors on blood vessels of skeletal muscle and coronary artery?
Binding of epinephrine causes ? NE? |
β2
dilatation Dilatation |
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Epinephrine affect on:
Systsolic pressure? Diastolic pressure? |
++
- |
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Nor-epinephrine
Systsolic pressure? Diastolic pressure? |
+++
++ |
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receptors for
GIT Motility and tone sphincter |
α1α1, α2, β2
E: relaxation of smooth muscle and contraction of sph. NE: relaxation of smooth muscle and contraction of sph. |
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Receptors in Smooth muscle of
BRONCHIAL muscle? E: NE: |
β2
Relaxation Relaxation |
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Receptors in Smooth muscle of
Uterus? E: NE: |
α1, α2, β2
E: Relaxation NE: Contraction |
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What is the rank order of potency for alpha receptors?
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Epinephrine
Norepinephrine Isoproterenol |
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What type of receptors are present in the blood vessels of skeletal muscles, liver, and smooth muscles of bronchus, urogenital system (bladder) and uterus and have a higher affinity for epinephrine over norepinephrine?
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β2 {EPI>NE}
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Dextrusor muscle
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SMOOTH OF BLADDER
contracts when urinating to squeeze out urine. Otherwise, it remains relaxed to allow the bladder to fill. Related are the urethral sphincter muscles |
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receptors for Dextrusor muscle
E: NE: |
β2
E: Relaxation (so holding onto urine) NE: none |
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receptors for urethral sphincter muscles
E: NE: |
α1:
E: Contraction?? check this NE: Contraction |
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At medium-high doses what receptor does dopamine interact with?
To what end? What is effector organ? |
B1 receptors, exerts positive inotropic effect on myocardium
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At very high concentrations what receptor does dopamine interact with?
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Alpha1 adrenergic receptors, vasoconstriction
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What effect does dopamine have on the body at low concentrations?
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Increases GFR
Increases renal blood flow Increases Na excretion |
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At low concentrations what receptor does dopamine interact with?
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D1-dopaminergic receptors
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So which catecholamine has strong effect on blood pressure:
- epinephrine or norepinephrine? |
norepinephrine>epinephrine
(in fact epi. reduces diastolic pressure) |
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Only receptor that doesn't prefer epinephrine?
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β1-receptors
equal affinity for epinephrine and nor-epinephrine |
