Integration of the Autonomic Nervous System

Anatomy and Physiology

L|E|C|O|M Mathew J. Bateman, Ph.D.

Somatic vs. Autonomic

Dual Innervation

Innervation of the HeartSympathetic Effect and Receptor Type

Parasympathetic Effect

Heat rate

and force

Increase (β1, β2) Decreased

Autonomic Vascular ControlSympathetic Effect and Receptor Type

Parasympathetic Effect

Blood vessels

(Vascular smooth muscle)

Vasodilation

(β2) – relaxation

Slight vasodilation

Vasoconstriction

(α1, α2) – contraction

Autonomic Vascular Control

Blood

Endothelial Cells

Vascular Smooth Muscle

Acetylcholine

Blo

od

Ves

sel

Wal

l M

Nitric Oxide-

cGMP

2

Epinephrine

cAMP

-1

Norepinephrine

+High doses

- +Relax (vasodilation) Contract (vasoconstriction)

Blood Vessels without Dual Innervation

Baroreceptor Reflexes

Movie

Innervation of the Respiratory System

Sympathetic Effect and Receptor Type

Parasympathetic Effect

Bronchial Muscle Bronchodilation Relaxation (β2)

Bronchoconstriction

Contraction

Muscus glands Decrease secretion (α1)

No effect

Increase (β2)

Innervation of the Digestive System

Sympathetic Effect and Receptor Type

Parasympathetic Effect

Salivary Glands Thick mucus secretion (α1)

Thin serous secretion

Gastrointestinal motility

Decreased

(α1, α2, β1, β2)

Increased

Gastrointestinal secretion

Decreased (α2) Increased

Liver Glycogen breakdown

(α1, β2)

Glycogen synthesis

Pancreatic enzymes secretion

Decreased (α1) Increased

Pancreatic insulin secretion

Decreased (α2)

Increased (β2)

No effect

Autonomics of

Defecation

Innervation of the Urinary System

Sympathetic Effect and Receptor Type

Parasympathetic Effect

Kidneys Reduce urine output (α1, α2)

Renin secretion (β1)

No effect

Bladder wall No effect Contraction

Internal urethral sphincter

Contraction, urine retention (α1)

Relaxation, urine release

Autonomic Control of Urination

Autonomics and Reproduction

Sympathetic Effect and Receptor Type

Parasympathetic Effect

Penile or clitoral erection

No effect Stimulation

Glandular secretion No effect Stimulation

Orgasm, smooth muscle roles

Stimulation (α1) No effect

Uterus Relaxation (β2)

Labor Contraction (α1)

Innervation of the Integumentary System

Sympathetic Effect and Receptor Type

Parasympathetic Effect

Merocrine sweat glands (cooling)

Secretion (muscarinic) No effect

Apocrine sweat glands (scent)

Secretion (α1) No effect

Piloerector muscles Hair erection (α1) No effect

Innervation of the Eye

Sympathetic Effect and Receptor Type

Parasympathetic Effect

Iris Pupillary dilation (α1) Pupillary constriction

Ciliary muscles and lens

Relaxation for far vision(β2)

Contraction for near vision

Lacrimal (tear) gland None Secretion

Autonomic Control of the Iris