Autonomics

Question 1

Name 5 functions of the PNS.

Answer 1

Rest & Digest

Slows heart rate
Contracts the pupils
Stimulates digestion
Stimulates nasal secretions
Stimulates liver, kidneys, gall bladder
Sexual arousal (maintain erection)

Question 2

Name 5 functions of the SNS.

Answer 2

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)

Question 3

Where are sympathetic preganglionic neurons located?

Answer 3

T1 - L2 in the lateral horn of the gray matter

Question 4

Describe the route of preganglionic sympathetic neurons.

Answer 4

“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.

Question 5

Describe the route of postganglionic sympathetic neurons.

Answer 5

“Short arms, Long fingers”

Postganglionic sympathetic fibers leave the sympathetic ganglion through gray rami and travel to their effector organ.

Question 6

What are the 4 ways preganglionic sympathetic neurons can synapse?

Answer 6

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

Question 7

Where are parasympathetic preganglionic cell bodies?

Answer 7

Parasympathetic preganglionic cell bodies are in the brainstem and S2 - S4.

Question 8

What nerves are used for the traveling of parasympathetic preganglionic neurons?

Answer 8

Preganglionic fibers travel through cranial nerves III, VII, IX, and X, and spinal nerves S2-S4. They use CN V to carry them.

Question 9

Describe the route of preganglionic parasympathetic neurons.

Answer 9

“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.

Question 10

Describe the route of postganglionic parasympathetic neurons.

Answer 10

“Long Arms, Short fingers”

Postganglionic parasympathetic neurons leave ganglions that are very near the effector organ for synapsis.

Question 11

Where are sympathetic and parasympathetic ganglia located?

Answer 11

Sympathetic ganglia are located in the sympathetic trunk OR in collateral ganglia.

Parasympathetic ganglia are located in peripheral ganglia near the effector organ.

Question 12

Which portion of sympathetic neurons is myelinated?

Answer 12

Preganglionic fibers are short and myelinated.

Question 13

Which portion of parasympathetic neuron is myelinated?

Answer 13

Preganglionic fibers are long and myelinated.

Question 14

Which fibers release ACh?

Answer 14

ALL PREGANGLIONIC FIBERS RELEASE ACh (both SNS and PNS fibers) and PNS postganglionic fibers release ACh

Question 15

Which fibers release NE?

Answer 15

SNS postganglionic fibers release NE EXCEPT fibers that innervate sweat glands and some blood vessels in skin and skeletal muscle

Question 16

What causes the fight/flight response from SNS postganglionic neurons?

Answer 16

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

Question 17

What is WIGO?

Answer 17

“White in, Gray out”

White rami (myelinated fibers) enter the sympathetic chain ganglia, gray rami (unmyelinated fibers) exit the chain ganglia—WIGO.

Question 18

Why are sympathetic splanchnics an exception?

Answer 18

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).

Question 19

Are the splanchnics sympathetic or parasympathetic?

Answer 19

The pelvic splanchnics (S2-S4) are parasympathetic.

Question 20

What is Point-and-Shoot?

Answer 20

The parasympathetic splanchnics maintain an erection. The sympathetic splanchnics cause an orgasm.

Question 21

What are the parasympathetic peripheral ganglia for CN 3,7,9?

Answer 21

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

Question 22

Which parasympathetic ganglia does the Vagus nerve use?

Answer 22

The Vagus nerve does not use COPS. They use ganglia near the target organ.

Question 23

Describe the route of CN III to and from its ganglion.

Answer 23

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.

Question 24

Describe the route of CN VII TO the pterygopalatine ganglion.

Answer 24

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).

Question 25

Describe the route of CN VII FROM the pterygopalatine ganglion.

Answer 25

Postganglionic PS fibers leave the pterygopalatine ganglion in several directions to join V2.

1. On the Zygomatic division of V2 - travels to unite with the lacrimal nerve (branch of CN V1)
2. On the Descending palatine nerves (CN V2 branch) - include greater and lesser palatine nerves
3. On Nasopalatine Nerves (CN V2 branches) - to glands of the nasal mucosa.

Question 26

What are the functions of the greater and lesser palatine nerves?

Answer 26

Greater palatine PSN - synapses on hard palate and regulates glands

Lesser Palatine PSN - synapses at soft palate and controls taste receptors and mucus glands

Question 27

Describe the route of CN VII to and from the submandibular ganglion.

Answer 27

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.

Question 28

Describe the route of CN IX to and from its ganglion.

Answer 28

“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.

Question 29

What is Herring’s nerve?

Answer 29

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.