Chapter 15 Study Guide ( a.k.a.= also known as )

somatic motor neuron neurotransmitters ACh (acetylcholine) only

autonomic motor neuron neurotransmitters ACh or NE (norepinephrine a.k.a. noradrenaline)

2 principal branches of ANS have opposing actions

sympathetic NS = thoracolumbar division / outflow (T1-12, L1-2)

vertebral chain (a.k.a. sympathetic trunk, a.k.a. paravertebral) ganglia

prevertebral (a.k.a. collateral) ganglia

parasympathetic NS = craniosacral division / outflow (S2-4, brainstem)

terminal (a.k.a. intramural) ganglia

autonomic plexuses tangled networks of sympathetic & parasympathetic neurons

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SYMPATHETIC

O---< ACh (nicotinic) O---< NE (adrenergic) (most effectors)

O---< ACh (nicotinic) O---< ACh (muscarinic) (sweat glands, a few effectors)

 

PARASYMPATHETIC

O---< ACh (nicotinic) O---< ACh (muscarinic) (effectors)

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cholinergic neurons release ACh, cholinergic receptors bind ACh

(cholinergic) nicotinic receptors sympathetic & parasympathetic neurons and also motor end plates

(cholinergic) muscarinic receptors parasympathetic effectors (and very few sympathetic effectors = sweat glands)

 

adrenergic neurons release NE, adrenergic receptors bind NE

(adrenergic) a 1, b 1 receptors binding of NE generally produces excitation of effector

(adrenergic) a 2, b 2 receptors binding of NE generally produces inhibition of effector

 

agonist binds to & activates receptor (mimics neurotransmitter)

antagonist binds to & blocks receptor (prevents neurotransmitter from having effect)

hypothalamus regulates balance between sympathetic tone & parasympathetic tone

 

SYMPATHETIC STIMULATION PARASYMPATHETIC STIMULATION

[ α or β (adrenergic) receptors ] [ muscarinic (cholinergic) receptors ]

FIGHT or FLIGHT FEED or BREED / REST or DIGEST

 

INHIBITS DIGESTION PROMOTES DIGESTION

inhibits digestive enzyme secretion & digestive juices promotes digestive enzyme secretion & digestive juices

decreases GI motility increases GI motility

contracts sphincters

increases activity / release of hormones & enzymes increases glycogen synthesis

for breaking down glycogen & triglycerides

 

INHIBITS URINATION PROMOTES URINATION

increases ADH - antidiuretic hormone

relaxes bladder wall contracts bladder wall

contracts sphincter relaxes sphincter

 

INCREASES WORK OF HEART DECREASES WORK OF HEART

increases heart rate & force of contraction decreases heart rate & force of contraction

 

INCREASES WORK OF LUNGS DECREASES WORK OF LUNGS

dilates airways constricts airways

 

PUPIL DILATES PUPIL CONSTRICTS

 

INCREASES SEXUAL ACTIVITY

vasodilation in clitoris and penis