bbs ii slide autonomic nervous system

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Autonomic Nervous System

I. Divisions

A. Sympathetic

• _{fight or flight response}

B. Parasympathetic

• _{rest and digestion}

II. Involuntary Motor System

A. Autonomic vs. Somatic motor systems

1. Somatic

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2 2. Autonomic

• _involuntary

• _{disynaptic (preganglion, postganglion)} • _{Excitatory and inhibitory}

III General nerve pathways

A. Sympathetic

• _{Preganglion cell body – gray matter}

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• _{axons of postganglions exit via}

Spinal nerve

Sympathetic nerve

Exceptions: some pre do not synapse at symp chain

Splanchnic nerve

axons of preganglion exit Splanchnic nerve and

synapse at collateral ganglion w/post

Adrenal gland

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• cell bodies of preganglion – brainstem (nuclei) and sacral region of spinal cord

• _{axons move through cranial nerves}

and through spinal nerves

• synapse w/ postganglion at ganglia near or in the target IV. Signal transmission

A. Sympathetic

• Preganglion secretes Acetylcholine (Cholinergic)

• _{Postganglion – receptor = Nicotinic}

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• _{Target (smooth muscle, cardiac, glands)}

Receptor = Adrenergic ( , )

Sweat Glands

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• _{Preganglion secretes Acetylcholine (Cholinergic)} • _{Postganglion – receptor = nicotinic}

• _{Postganglion secretes Acetylcholine} • _{Target (Smooth muscle, heart, glands)}

receptor = muscarinic

V. ANS generalized

A. Regulated

B. Excitatory and inhibitory

• _{depends on the target organ}

C. Opposite effects

VI. Autonomic control

A. Cardiovascular function

• _{Sympathetic: Norepinephrine}

-Increases cardiac muscle contractions

Increases blood pressure

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B. Pupillary light reflex

1. Parasympathetic

• _{constricts pupil}

2. Sympathetic

• _{Dilates pupil}

C. Salivary glands

1. Sympathetic

• _{viscous secretion/ vasoconstriction of blood vessels}

2. Parasympathetic