Autonomic Receptors

Structural family Functional families Receptor Physiological ligands Effectors, Transducers, Major functions G Protein Coupled Receptors (GPCR) Muscarinic receptors M1 Acetylcholine Gq-coupled Increased phospholipase C increased IP3, diacylglycerol, cytoplasmic calcium M2 Acetylcholine Gi-coupled Decreased adenylyl cyclase decreased cAMP M3 Acetylcholine Gq-coupled Increased phospholipase C increased IP3, diacylglycerol, cytoplasmic calcium Alpha-adrenergic receptors Alpha1 (α1) Epinephrine, norepinephrine Gq-coupled Increased […]

The Effects of the Autonomic Nervous System on Organ Systems

Sympathetic Parasympathetic Organ Target Actiona Receptorb Actiona Receptorb Eye Iris Radial muscle Contracts α1 — — Circular muscle — — Contracts M3 Ciliary muscle [Relaxes] β Contracts M3 Heart Sinoatrial node Accelerates β1, β2 Decelerates M2 Ectopic pacemakers Accelerates β1, β2 — — Contractility Increases β1, β2 Decreases (atria) [M2] Blood vessels Skin, splanchnic vessels […]