visceral motor system

visceral motor system

autonomic motor system

sympathetic NS

fight or flight

parasympathetic NS

rest and digest

visceral motor system

links CNS to a gland, internal organ, or blood vessel

• autonomic

What NT is released by preganglionic neurons in ANS

acetylcholine

what NT is released by postganglionic neurons in sympathetic NS

norepinephrine

what NT is released by postganglionic neurons in parasympathetic NS

acetylcholine

two components of ANS pathway

1. preglanglionic neuron

2. postganglionic neurons

paravertebral ganglia

autonomic ganglia used in sympathetic NS

• either side of vertebral column

• looks like chain

• postganglionic cells → muscles outside the body wall

preverterbral ganglia

autonomic ganglia in sympathetic NS

• anterior to vertebra

• postganglion cells → targets within the body wall

intramural ganglia

autonomic ganglia in parasympathetic NS

• within wall/ or close to effector organ

• targets in thorax, abdomen, and pelvis

• lower SC

where are preganglionic cell bodies located for sympathetic division?

in lateral horn of spinal chord

• only in T1-L2

where do pregaglionic axons leave SC for sympathetic

leave through ventral root → go through white ramus (off ramp)→ synapse in chain ganglion

if sympathetic pre ganglion axons synapse in paravertebral ganglion

they use grey ramus (like an on ramp) to get back to peripheral nerve → smooth muscle outside body wall

where are all the white rami?

between L1 and T2

where are grey rami located

all throughout the SC

sympathetic trunk

extends from skill to the coccyx

where are preganglionic sympathetic cell bodies found

only T1-L2

where are postganglionic sympathetic cell bodies found

throughout the whole body

3 did things a preganglionic axon can do when it enters the sympathetic trunk

1. immediately synapse with a sympathetic ganglion

2. ascend or descend then synapse with a sympathetic ganglion

3. pass through sympathetic ganglion → go through splanchnic nerve → preverterbral autonomic ganglion

splanchnic nerve

carries preganglionic axon from sympathetic ganglion → preverterbral autonomic ganglion

major functions of sympathetic dictions 6

• incr heart rate

• incr blood pressure

• pupil dilation

• incr sweating

• decrease digestion

• relax bladder

where are preganglionic neurons found in parasympathetic division?

nuclei in brainstem

S2-4 in spinal chord

where do preganglionic parasympathetic fibers travel out of brainstem?

CN III- pupil constriction

CN VII

CN X- input to body wall

CN IX

where do the preganglionic parasympathetic SC fibers go?

intramural ganglia

in cranial outflow, where are the preganglionic neurons located?

CN III - edinger-westphal nucleus in midbrain

CN VII and IX- superior and inferior salvatore nucleus in pons

CN X- nucleus ambiguous and dorsal motor nucleus

cranial outflow preganglionic fibers carried by… (4)

Oculomotor CNIII

facial CN VII

glossopharyngeal CN IX

vagus CN X

sacral outflow parasympathetic preganglionic neurons located …

lateral horn of spinal gray matter

sacral outflow parasympathetic preganglionic fibers are carried by …

splanchnic nerves → intervate organs of pelvis and lower abdomen

function of parasympathetic division

• decr. heart rate

• pupil constriction

• decreased sweating

• incr gut motility

• contracts bladder

wallenberg’s syndrome (lateral medullary syndrome)

damage to lateral portion of medulla

• damage to spinothalamic (pain/temp contralateral body)

• spinal trigeminal tract (pain/temp face)

• damage to sympathetic ns

Horner’s Syndrome

sympathetic pathway lesion to any of the 3 neurons

ex. damage to first order neuron, preganglionic neuron, or postganglionic neuron

• loss of sympathetic ns to ipsilateral