Sympathetic and Parasympathetic Nervous System Receptors and Effects

Vocabulary practice flashcards detailing sympathetic and parasympathetic receptors, target organs, and physiological effects.

Adrenergic Receptors

The group of receptors comprising $\alpha_1$, $\alpha_2$, $\beta_1$, $\beta_2$, and $\beta_3$.

Cholinergic Receptors

The group of receptors comprising $N$, $M_1$, $M_2$, $M_3$, $M_4$, and $M_5$.

Eye: m. dilator pupillae (Sympathetic)

Innervated via $\alpha_1$ receptors to produce pupil dilation.

Eye: m. sphincter pupillae (Parasympathetic)

Innervated via $M_5$ receptors to produce pupil constriction.

Ciliary Muscle (Sympathetic)

Innervated via $\beta_2$ receptors to produce relaxation for distance vision.

Ciliary Muscle (Parasympathetic)

Innervated via $M_3$ receptors to produce contraction for near vision.

Heart (Sympathetic)

Innervated via $\beta_1$ receptors to produce increased heart rate and contractility.

Heart (Parasympathetic)

Innervated via $M_2$ receptors to produce decreased heart rate and contractility.

Blood Vessels: Skin, Splanchnic Region (Sympathetic)

Innervated via $\alpha_1$ receptors to produce vasoconstriction.

Skeletal Muscles (Sympathetic)

Innervated via $\beta_2$ and $M_3$ receptors (cholinergic sympathetic fibers) to produce vasodilation.

Endothelium of Vessels in Heart, Brain, and Internal Organs (Parasympathetic)

Innervated via $M_3$ and $M_5$ receptors to produce indirect vasodilation via NO formation.

Bronchi / Bronchioles (Sympathetic)

Innervated via $\beta_2$ receptors to produce bronchodilation.

Bronchi / Bronchioles (Parasympathetic)

Innervated via $M_3$ receptors to produce bronchoconstriction.

GI Tract: Stomach / Intestinal Wall

Undergoes relaxation via sympathetic $\alpha_2$ receptors and contraction via parasympathetic $M_3$ receptors.

Sphincters

Undergo contraction via sympathetic $\alpha_1$ receptors and relaxation via parasympathetic $M_3$ receptors.

GI Tract: Glands

Undergo relaxation via sympathetic $\beta_2$ receptors and contraction via parasympathetic $M_3$ receptors.

Genitourinary Smooth Muscles: Bladder Muscle Wall (Detrusor)

Associated with sympathetic $\alpha$ receptors causing ejaculation, and parasympathetic $M$ receptors causing erection.

Urethral Sphincter (Table Listing)

Listed with sympathetic receptors $\alpha$ and $\beta_2$ associated with glycolysis and gluconeogenesis.

Uterus (Table Listing)

Listed with sympathetic receptor $\beta_3$ associated with lipolysis.

Seminal Vesicles, Penis (Table Listing)

Listed with sympathetic receptor $\beta_1$ associated with renin release.