Receptor Actions Flashcards
alpha1 effects
SMOOTH MUSCLE CONTRACTION: Vascular Smooth muscle, GI sphincters, Pupillary dilator muscle (mydriasis)
[Tamsulosin is alpha1 blocker]
alpha2 effects
SLOW THINGS DOWN: CNS autoreceptors to decrease sympathetic outflow, dec. insulin, dec. lipolysis.
BUT INCREASES PLATELET AGGREGATION
beta1 effects
HEART AND KIDNEY: Inc. HR, Contractility, Inc. Renin release, Inc. Lipolysis [Both beta receptors inc. lipolysis [heart needs fatty acids!!!]]
beta2 effects
SMOOTH MUSCLE RELAXATION: Uterus (tocolysis), GI tract (slows motility), Bladder relaxation, Bronchodilation. Coronary, hepatic, and skeletal muscle arteries vasodilate [needed to run away].
Heart: Weaker than Beta1. Inc. HR, contractility.
Increases insulin secretion.
Glycogenolysis and GNG in liver, glycogen in skeletal muscle.
Why do beta receptors both increase lipolysis?
Because the heart only uses fat for energy so you need the fuel.
Insulin and adrenergic receptors
Alpha2 slows down secretion (slows down everything except clotting)
Beta2 speeds up secretion
D1 effects
Gs: relaxes renal vascular smooth muscle
D2 effects
Gi: Modulates transmitter release, especially in brain.
H2 effects
Gs: Stimulates gastric acid secretion
H1 effects
Gq: nasal and bronchial mucus secretion, inc. vascular permeability, contraction of bronchioles, pruritus, and pain [H1 blockers are like cetirizine for allergies]
V1 effects
Gq: inc. vascular smooth muscle contraction
V2 effects
Gs: Inc. H2O permeability in medullary collecting tubules. [V2 in 2 kidneys]
M1 effects
Gq: CNS, enteric nervous system
M2 effects
Gi: Dec. HR and contractility of atria
M3 effects
Rest and DIGEST: gland secretions, peristalsis, peeing, breathing at rest.
Visual: parasympathetic: miosis and accommodation
Inc. exocrine gland secretions (lacrimal, salivary, gastric acid), inc. gut peristalsis, inc. bladder contraction, bronchoconstriction, inc. pupillary sphinter muscle contraction (miosis), ciliary muscle contraction (accommodation)
