Ganong's Review of Medical Physiology, 23rd Edition

CHAPTER 17

The Autonomic Nervous System 267

TABLE 17–1
Responses of some effector organs to autonomic nerve activity.

Sympathetic Nervous System

Effector Organs Parasympathetic Nervous System Receptor Type Response

Eyes

Radial muscle of iris —

a

α

1

Contraction (mydriasis)

Sphincter muscle of iris Contraction (miosis) —

Ciliary muscle Contraction for near vision —

Heart

S–A node Decreases heart rate

β

1

Increases heart rate

Atria & ventricle Decreases contractility

β

1

,

β

2

Increases contractility

AV node & Purkinje Decreases conduction velocity

β

1

,

β

2

Increases conduction velocity

Arterioles

Coronary —

α

1

,

α

2

Constriction

β

2

Dilation

Skin —

α

1

,

α

2

Constriction

Skeletal muscle —

α

1

Constriction

β

2

, M Dilation

Abdominal viscera —

α

1

Constriction

Salivary glands Dilation

α

1

,

α

2

Constriction

Renal —

α

1

Constriction

Systemic veins

—

α

1

,

α

2

Constriction

β

2

Dilation

Lungs

Bronchial muscle Contraction

β

2

Relaxation

Stomach

Motility and tone Increases

α

1

,

α

2

,

β

2

Decreases

Sphincters Relaxation

α

1

Contraction

Secretion Stimulation? Inhibition

Intestine

Motility and tone Increases

α

1

,

α

2

,

β

1

,

β

2

Decreases

Sphincters Relaxation

α

1

Contraction (usually)

Secretion Stimulation

α

2

Inhibition

Gall bladder

Contraction

β

2

Relaxation

Urinary bladder

Detrusor Contraction

β

2

Relaxation

Sphincter Relaxation

α

1

Contraction

(

continued

)