Autonomics Flashcards
Name 5 functions of the PNS.
Rest & Digest
Slows heart rate Contracts the pupils Stimulates digestion Stimulates nasal secretions Stimulates liver, kidneys, gall bladder Sexual arousal (maintain erection)
Name 5 functions of the SNS.
Feed, Fight, flight, Fornication
Raises heart rate Dilates pupils Inhibits digestion Inhibits nasal secretions Inhibits producution of saliva Inhibits liver, kidneys, gall bladder Stimulates sweating Increases muscle strength Orgasm (Cause ejaculation)
Where are sympathetic preganglionic neurons located?
T1 - L2 in the lateral horn of the gray matter
Describe the route of preganglionic sympathetic neurons.
“Short arms, Long fingers”
Preganglionic sympathetic neurons send fibers out of the ventral root, where they leave white rami and synapse in the sympathetic ganglion.
Describe the route of postganglionic sympathetic neurons.
“Short arms, Long fingers”
Postganglionic sympathetic fibers leave the sympathetic ganglion through gray rami and travel to their effector organ.
What are the 4 ways preganglionic sympathetic neurons can synapse?
Synapse with one or more neurons in the sympathetic trunk directly across from them
Ascend or descend in the trunk before synapsing
Pass through the sympathetic trunk and synapse with a collateral ganglion outside the sympathetic trunk
Directly stimulate the release of epinephrine and norepinephrine from the adrenal medulla
Where are parasympathetic preganglionic cell bodies?
Parasympathetic preganglionic cell bodies are in the brainstem and S2 - S4.
What nerves are used for the traveling of parasympathetic preganglionic neurons?
Preganglionic fibers travel through cranial nerves III, VII, IX, and X, and spinal nerves S2-S4. They use CN V to carry them.
Describe the route of preganglionic parasympathetic neurons.
“Long Arms, Short fingers”
Preganglionic parasympathetic fibers exit the brainstem or S2-S4, and travel a long way to their peripheral ganglion where they synapse.
Describe the route of postganglionic parasympathetic neurons.
“Long Arms, Short fingers”
Postganglionic parasympathetic neurons leave ganglions that are very near the effector organ for synapsis.
Where are sympathetic and parasympathetic ganglia located?
Sympathetic ganglia are located in the sympathetic trunk OR in collateral ganglia.
Parasympathetic ganglia are located in peripheral ganglia near the effector organ.
Which portion of sympathetic neurons is myelinated?
Preganglionic fibers are short and myelinated.
Which portion of parasympathetic neuron is myelinated?
Preganglionic fibers are long and myelinated.
Which fibers release ACh?
ALL PREGANGLIONIC FIBERS RELEASE ACh (both SNS and PNS fibers) and PNS postganglionic fibers release ACh
Which fibers release NE?
SNS postganglionic fibers release NE EXCEPT fibers that innervate sweat glands and some blood vessels in skin and skeletal muscle
What causes the fight/flight response from SNS postganglionic neurons?
Prolonged activation of SNS post-ganglionic neurons can elicit release of adrenaline from the adrenal medulla. Adrenaline will bind adrenergic receptors on peripheral tissues that results in flight/fight response
What is WIGO?
“White in, Gray out”
White rami (myelinated fibers) enter the sympathetic chain ganglia, gray rami (unmyelinated fibers) exit the chain ganglia—WIGO.
Why are sympathetic splanchnics an exception?
The splanchnics(T5 - T12 and S2-4; greater, lesser, and least) are long SNS preganglionics that synapse on ganglia on or near the aorta and are near their target organs (SNS fibers that are long arms, short fingers).
Are the splanchnics sympathetic or parasympathetic?
The pelvic splanchnics (S2-S4) are parasympathetic.
What is Point-and-Shoot?
The parasympathetic splanchnics maintain an erection. The sympathetic splanchnics cause an orgasm.
What are the parasympathetic peripheral ganglia for CN 3,7,9?
C.O.P.S
Ciliary Ganglion - CN 3 (oculomotor)
Otic Ganglion - CN 9 (Glossopharyngeal)
Pterygopalatine Ganglion - CN 7 (Facial)
Submandibular Ganglion - CN 7
**Postganglionics jump on V to reach effectors
Which parasympathetic ganglia does the Vagus nerve use?
The Vagus nerve does not use COPS. They use ganglia near the target organ.
Describe the route of CN III to and from its ganglion.
Oculomotor PNS fibers travel through the superior orbital fissure to synapse in the ciliary ganglion behind the orbit. The PS fibers follow the inferior division of the oculomotor nerve
From the ciliary ganglion, the postganglionic parasympathetic nerve fibers leave via short ciliary fibers and pass into the nasociliary nerve (from CN V1). The short ciliary nerves provide parasympathetic innervation the orbit.
Describe the route of CN VII TO the pterygopalatine ganglion.
The greater petrosal nerve branches from the facial nerve, travels through the middle ear and combines with the deep petrosal nerve (sympathetic fibers) to form the Vidian nerve of the pterygoid canal. The Vidian nerve synapses at the pterygoid ganglion (associated with the maxillary division of CN V).
Describe the route of CN VII FROM the pterygopalatine ganglion.
Postganglionic PS fibers leave the pterygopalatine ganglion in several directions to join V2.
- On the Zygomatic division of V2 - travels to unite with the lacrimal nerve (branch of CN V1)
- On the Descending palatine nerves (CN V2 branch) - include greater and lesser palatine nerves
- On Nasopalatine Nerves (CN V2 branches) - to glands of the nasal mucosa.
What are the functions of the greater and lesser palatine nerves?
Greater palatine PSN - synapses on hard palate and regulates glands
Lesser Palatine PSN - synapses at soft palate and controls taste receptors and mucus glands
Describe the route of CN VII to and from the submandibular ganglion.
The chorda tympani branches from CN 7 and travels through the middle ear and hitches a ride on the lingual branch of CN V3 to synapse at the at the submandibular ganglion.
Postganglionic fibers innervate the submandibular and sublingual glands at the submandibular ganglion.
Describe the route of CN IX to and from its ganglion.
“G.L.O.A.P”
Preganglionic fibers leave CN IX as the tympanic nerve and continue to the middle ear where they make up a tympanic plexus. The tympanic plexus of nerves form the lesser petrosal nerve and exit through the foramen ovale to synapse at the otic ganglion.
Postganglionic parasympathetic fibers travel with the auriculotemporal nerve (CN V3) to the parotid salivary gland.
What is Herring’s nerve?
Via Herring’s nerve, CN IX innervates the carotid sinus. An increase in BP stretches receptors in the sinus and these fire and cause the vagus to fire and slow the heart.
