Table 6–1 Responses of Effector Organs to Autonomic Nerve Impulses
ORGAN
SYSTEM
SYMPATHETIC
EFFECTa
ADRENERGIC PARASYMPATHETIC CHOLINERGIC
RECEPTOR
EFFECTa
RECEPTOR
TYPEb
TYPEb
Eye
Radial muscle,
iris
Contraction
(mydriasis)++
α1
Sphincter
muscle, iris
Ciliary muscle
Contraction (miosis)+++ M3, M2
Relaxation for far
vision+
β2
Lacrimal glands Secretion+
Contraction for near
vision+++
M3 , M2
Secretion+++
M3 , M2
Decrease in heart
rate+++
M2 >> M3
Decrease in
contractility++ and
shortened AP duration
M2 >> M3
Decrease in conduction
velocity; AV block+++
M2 >> M3
Little effect
M2 >> M3
Slight decrease in
contractility
M2 >> M3
Heartc
Sinoatrial node Increase in heart
rate++
Atria
Increase in
contractility and
conduction
velocity++
Atrioventricular Increase in
node
automaticity and
conduction
velocity++
His–Purkinje
system
Ventricle
Blood vessels
Increase in
automaticity and
conduction velocity
Increase in
contractility,
conduction velocity,
automaticity and
rate of
idioventricular
pacemakers+++
β1 > β2
β1 > β2
β1 > β2
β1 > β 2
β1 > β2
(Arteries and
arterioles)d
Coronary
Skin and
mucosa
Constriction+;
dilatione++
Constriction+++
Skeletal muscle Constriction;
dilatione,f++
Cerebral
α 1, α 2; β 2
α 1, α 2
α 1; β 2
Constriction (slight)
No innervationh
—
No innervationh
—
Dilationg,h (?)
—
No innervationh
—
No innervationh
—
No innervationh
—
Dilationh++
M3
α1
Pulmonary
Abdominal
viscera
Constriction+;
dilation
Constriction +++;
dilation +
Salivary glands Constriction+++
Renal
Constriction++;
dilation++
α 1; β 2
α 1; β 2
α 1, α 2
α 1, α2;
No innervationh
β 1, β 2
(Veins)d
Constriction;
dilation
α 1, α 2; β 2
Endothelium
Activation of NO
synthaseh
M3
Contraction
M 2 = M3
Stimulation
M3 , M2
Increasei+++
M 2 = M3
Lung
Tracheal and
Relaxation
bronchial smooth
muscle
Bronchial
glands
Decreased secretion,
increased secretion
β2
α1
β2
Stomach
Motility and
Decrease
α 1, α 2, β 1, β 2
tone
Sphincters
Secretion
(usually)i+
Contraction
(usually)+
Relaxation (usually)+
M3 , M2
Stimulation++
M3 , M2
Increasei+++
M3 , M2
Relaxation (usually)+
M3 , M2
Stimulation++
M3 , M2
Contraction+
M
No innervation
—
Contraction+++
M 3 > M2
Relaxation++
M 3 > M2
Increase (?)
M
Variablej
M
Erection+++
M3
α1
Inhibition
α2
Intestine
Motility and
tone
Sphincters
Decreaseh+
α 1, α 2, β 1, β 2
Contraction+
α1
Secretion
Inhibition
α2
Gallbladder and Relaxation+
ducts
β2
Kidney
Renin secretion Decrease+;
increase++
α 1; β 1
Urinary bladder
Detrusor
Trigone and
sphincter
Relaxation+
β2
Contraction++
α1
Ureter
Motility and
tone
Increase
Uterus
Pregnant
contraction;
α1
α1
Relaxation
β2
Nonpregnant
relaxation
β2
Sex organs, male Ejaculation+++
α1
Skin
Pilomotor
muscles
Sweat glands
Contraction++
Localized
secretionk++
α1
α1
Generalized
secretion+++
Spleen capsule
M3 , M2
Contraction+++
—
—
α1
Relaxation+
—
β2
Adrenal medulla —
Secretion of
epinephrine and
norepinephrine
Skeletal muscle
Liver
Increased
contractility;
glycogenolysis; K+
uptake
Glycogenolysis and
gluconeogenesis+++
N ( 3 )2 ( 4 )3 ; M
(secondarily)
—
—
—
—
Secretion++
M3 , M2
β2
α 1,
2
Pancreas
Acini
Islets (
cells)
Fat cellsl
Decreased
secretion+
α1
Decreased
secretion+++
α2
Increased secretion+
β2
Lipolysis+++;
(thermogenesis)
α 1, β 1,
—
β 2, β 3
Inhibition of
lipolysis
α2
—
—
K+ and water
secretion+++
M3 , M2
Nasopharyngeal —
glands
Secretion++
M3 , M2
Pineal glands
Melatonin synthesis
—
Posterior
pituitary
ADH secretion
β1
Inhibition of NE
release
α 2A > α 2C (α
2B)
Salivary glands
K+ and water
secretion+
α1
—
Autonomic nerve
endings
Sympathetic
terminals
Autoreceptor
Heteroreceptor —
Inhibition of NE release
M2 , M4
Parasympathetic —
terminal
Autoreceptor
Heteroreceptor Inhibition of ACh
release
a
Inhibition of ACh release M2, M4
α 2A > α 2C