This is a table of neurotransmitter actions in the ANS (autonomic nervous system). It includes the circulatory system, the respiratory system, the visual system, the digestive system, the endocrine system, the urinary system, the reproductive system, and the integumentary system. Both effects of the sympathetic nervous system (adrenergic) and parasympathetic nervous system (muscarinic) are included.
Circulatory system
Heart
Target Sympathetic (adrenergic) Parasympathetic (muscarinic) cardiac output β1, (β2): increases M2: decreases SA node: heart rate (chronotropic) β1, (β2): increases M2: decreases Atrial cardiac muscle: contractility (inotropic) β1, (β2): increases M2: decreases at AV node β1: increases conduction increases cardiac muscle automaticity M2: decreases conduction Atrioventricular block Ventricular cardiac muscle β1, (β2): increases contractility (inotropic) increases cardiac muscle automaticity ---
Blood vessels
Target Sympathetic (adrenergic) Parasympathetic (muscarinic) vascular smooth muscle in general α1: contracts; β2: relaxes M3: relaxes renal artery α1: constricts --- larger coronary arteries α1 and α2: constricts --- smaller coronary arteries β2: dilates --- arteries to viscera α: constricts --- arteries to skin α: constricts --- arteries to brain α1:Circulation & Lung Physiology I M.A.S.T.E.R. Learning Program, UC Davis School of Medicine constricts --- arteries to erectile tissue α1: constricts M3: dilates arteries to salivary glands α: constricts M3: dilates hepatic artery α: constricts --- arteries to skeletal muscle β2: dilates --- Veins α1 and α2: constricts β2: dilates ---
Other
Target Sympathetic (adrenergic) Parasympathetic (muscarinic) platelets α2: aggregates --- mast cells - histamine β2: inhibits ---
Respiratory system Target Sympathetic (adrenergic) Parasympathetic (muscarinic) smooth muscles of bronchioles* β2: relaxes (major contribution) α1: contracts (minor contribution) M3: contracts
✱ The bronchioles have no sympathetic innervation, but are instead affected by circulating adrenaline
Visual system Target Sympathetic (adrenergic) Parasympathetic (muscarinic) Pupil dilator muscle α1: Dilates (causes mydriasis) Iris sphincter muscle - M3: contracts (causes miosis) Ciliary muscle β2: relaxes (causes long-range focus) M3: contracts (causes short-range focus)
Digestive system Target Sympathetic (adrenergic) Parasympathetic (muscarinic) salivary glands: secretions β: stimulates viscous, amylase secretions α1: stimulates potassium secretions M3: stimulates watery secretions lacrimal glands (tears) β: stimulates protein secretion secretion of tears by stimulating muscarinic receptors (M3) juxtaglomerular apparatus of kidney β1: renin secretion --- parietal cells --- M1: Gastric acid secretion liver α1, β2: glycogenolysis, gluconeogenesis --- adipose cells β1, β3: stimulates lipolysis --- GI tract (smooth muscle) motility α1, α2, β2: decreases M3, (M1): increases sphincters of GI tract α1, α2, β2: contracts M3: relaxes glands of GI tract no effect M3: secretes
Endocrine system Target Sympathetic (adrenergic) Parasympathetic (muscarinic) pancreas (islets) α2: decreases insulin secretion from beta cells, increases glucagon secretion from alpha cells M3: increases secretion of both insulin and glucagon. adrenal medulla N (nicotinic ACh receptor): secretes epinephrine and norepinephrine ---
Urinary system Target Sympathetic (adrenergic) Parasympathetic (muscarinic) Detrusor urinae muscle of bladder wall β2, β3: relaxes M3: contracts internal urethral sphincter α1: contracts M3: relaxes
Reproductive system Target Sympathetic (adrenergic) Parasympathetic (muscarinic) uterus α1: contracts (pregnant) β2: relaxes (non-pregnant) --- genitalia α1: contracts (ejaculation) M3: erection
Integumentary system Target Sympathetic (muscarinic and adrenergic) Parasympathetic sweat gland secretions α1: stimulates (minor contribution) M: stimulates (major contribution) arrector pili α1: stimulates ---
References