Autonomic Nervous System Receptors & Actions

Myocardial Sympathetic Effect of β1 Receptor Activation

↑ Contractility

Parasympathetic Receptor That Decreases Contractility of the Heart

M2

Receptor that Increases SA Node Firing Rate Under Sympathetic Stimulation

β1

Parasympathetic Receptor That Decreases SA Node Activity

M2

Effect of β1 Stimulation on AV Node and His-Purkinje System

↑ Automaticity & conduction velocity (CV)

Receptor That Decreases AV Node Conduction

M2

Receptors Mediating Arterial Constriction

α1 > α2

Receptors Causing Venous Constriction

α2 > α1

Effect of Dopamine (DA) Receptors in Renal and Mesenteric Beds

Vasodilation

Receptor That Dilates Skeletal Muscle and Coronary Vessels

β2

Receptor That Relaxes Bronchial Smooth Muscle

β2 (sympathetic)

Receptor That Constricts the Bronchial Tree

M3 (parasympathetic)

Receptor That Increases Renin Release

β1

Receptor That Promotes Diuresis (via ADH inhibition)

α2

Receptor That Contracts Radial Muscle (Mydriasis)

α1

Receptor That Contracts Sphincter Muscle (Miosis)

M2, M3

Receptor That Relaxes Ciliary Muscle for Far Vision

β2

Receptor That Contracts Ciliary Muscle for Near Vision

M2, M3

Receptor That Decreases Salivary Secretion

α2

Receptor That Increases Salivary Secretion

M3

Receptors That Decrease GI Motility & Tone

α1, α2, β1, β2

Receptors That Increase GI Motility & Tone

M2, M3

Receptor That Contracts GI Sphincters

α1

Receptor That Relaxes GI Sphincters

M2, M3

Receptor That Relaxes Gallbladder & Ducts

β2

Receptor That Contracts Gallbladder & Ducts

M

Receptor That Increases Glucagon Secretion (α cells)

α1

Receptor That Decreases Insulin Secretion (β cells)

α2

Receptor That Increases Insulin Secretion

β2

Receptors Mediating Lipolysis in Adipocytes

α1, β1, β2, β3

Receptor That Mediates Glycogenolysis & Gluconeogenesis in the Liver

β2

Receptor That Causes RBC Release from the Spleen

α1

Receptor That Increases Thrombocyte Aggregation

α2

Receptor That Causes Uterine Contraction

α1

Receptor That Causes Uterine Relaxation

β2

Receptor That Relaxes the Detrusor Muscle

β2

Receptors That Contract the Detrusor Muscle

M2, M3

Receptor That Contracts the Trigone & Sphincter

α1

Receptors That Relax the Trigone & Sphincter

M2, M3

Sympathetic Receptor That Increases Sweat Secretion

α1

Parasympathetic Receptor That Increases Sweat Secretion

M

Receptor that Stimulates the Na⁺/K⁺ Pump, Lowering Plasma K⁺

β2