Autonomic Anatomy

Question 1

What is the role of the autonomic NS

Answer 1

Maintain a constant internal environment

Question 2

What are the sensory inputs to the ANS?

Answer 2

Visceral receptors within organs

Somatosensory receptors e.g. vision smell proprioception

Question 3

What is the motor output of the ANS

Answer 3

Smooth muscles found in blood vessels and Gi tract
cardiac muscles
secretory glands

Question 4

What are the divisions of the ANS and what is their role?

Answer 4

Sympathetic Alert and active (help to prepare for an emergency in extreme situations FFF)

Parasympathetic
Rest and digest energy conservation digestion and emptying

Enteric nervous system
digestion

Question 5

What are the characteristics of the SNS in terms of neurones?

Answer 5

short preganglioinc neurones and long post ganglionic neurones

Preganglioinc neurone cell bodies located in lateral horn of the spinal cord at T1 to L2 levels

Question 6

What spinal levels do pregnalgioinc neruones leave the spinal cord to enter the throacicolumbar region

Answer 6

T1-L2

Question 7

Detail SNS neurotransmission

Answer 7

Release of ACh from preganglionic neurone acts on neuronal nAChR’s

Post ganglionicn neurones release NA that acts on noradrenergic receptors A or B

Question 8

What are the possible pathways of pregnaglioninc sympathetic neruones after they leaves the ventral horn of the spinal cord and pass into the sympathetic chain ?

Answer 8

Synapse with a post ganglioinc neurone directly at the same vertebral level within the sympathetic ganglion enters the S ganglion via the white rami communicates synapses postganglionic neurone leaves the sympathetic chain via the grey rami communicates

Pregnaglionicn sympathetic fibre could alternatively r enter the S ganglion and travel cephalad or caudad to synapse with post gnaglioninc fibres in the sympathetic ganglia which leave via the grey rami communicates too.

May also directly leave the sympathetic ganglion and leave without synapsing to form prevertebral ganglia elsewhere in the PNS

Question 9

What are the three prevertebral ganglia?

Answer 9

Celiac ganglion
Superior mesenteric ganglion
Inferior mesenteric ganglion

Question 10

Whats the difference between a prevertebral ganglion and a paravertebral gnaglion

Answer 10

Paravertebral ganglion occur within the sympathetic chain they have short preganglionic and long postganglionic neurones

Prevertebral ganglion ganglia outside the paravertebral chain neurones have longer preganglionic neurones and shorter postganglionic neurones

Question 11

Where do parasympathetic preganglionic neurones arise from generally

Answer 11

Craniosacral sources

from specific cranial nerve nucli and from the S2-S4 segments

Question 12

Outline PNS neruotransmission

Answer 12

Preganglionic neurons release ACh action on nAChR’s on postganglionic neurones

Postganglionic neurone cell bodies located in the walls of target organs

Release ACh too that acts on muscarinic ACh receptors on target tissues

Question 13

What cranial nerves contribute to cranial sacral sutonomic outflow?

Answer 13

Oculomotor CNIII
Facial CNVII
Glossopharyngeal CNIX
Vagus CNX

Question 14

What cranial nerve supplies the head region only? What is the other nerve and what does it supply how does it get there?

Answer 14

CN’s III, VII, CNIX only supply the head

vagus supplies visceral in the thoracic and abdominal regions gets there via closely associating with blood vessels

Question 15

What do the sacral nerves supply?

Answer 15

the viscera in the abdomen and pelvis

Question 16

What nucleus does cranial nerve III originate from and where is the site of its ganglion?

Answer 16

Ediger-Westphal Nucleus

Ciliary ganglion behind eye

Question 17

Where do the post ganglionic fibres of CNIII synapse and what is the response

Answer 17

Sphincter pupillae muscles
Causes constriction of pupil

Ciliary muscles
causes contraction results in relaxation of suspense ligaments making lens shorter and fatter and more spherical allowing accommodation to see close up objects

Question 18

Where does CNVII originate from and where is its ganglion located? (COPS)

Answer 18

Superior salvatory nucleus

Pterygopalatine ganglion
AND
Submandibular ganglion

Question 19

What do the postganglionic fibres leaving the Submandibular ganglion synapse with and what is the response?

Answer 19

Submandibular gland
Sublingual gland

Increased secretions

Question 20

What do the postganglionicn fibres of leaving the Pterygopalatine ganglion supply? What is the response?

Answer 20

Lacrimal glands
Nasal mucosa and mucosa of palate

Increased secretions

Question 21

Where does CNIX originate from and where is its ganglion located? (COPS)

Answer 21

Inferior salvatory nucleus

Otic ganglion

Question 22

What do postganglionic fibres leaving the otic ganglion synapse with? What is the repsonse?

Answer 22

Parotid gland

Increased secretions

Question 23

What nucleus do the parasympathetic fibres of the vagus originate from?

Answer 23

The dorsal motor nuclus

Question 24

Where do preganglionic fibres from the vagus that effect the heart form a ganglion? What do the postganglionic fibres supply and what is the response?

Answer 24

Cardiac plexus

Postganglionic fibres supply the SAN and AVN

Decreases HR and Cardiac output

Question 25

Where do preganglionic fibres from the vagus that effect the bronchi form a ganglion? What do the postganglionic fibres supply and what is the response?

Answer 25

Pulmonary plexus

synapse with smooth muscle and glands in bronchi

Increased bronchial secretions and bronchoconstriction (don’t need as much air when resting)

Question 26

Where do preganglionic fibres of the vagus that effect the GIT terminate?

Answer 26

Oesophageal plexus

Question 27

How is the stomach and small intestine then effected from postganglionic fibres that leave the oesophageal plexus

Answer 27

Increased secretion
Increased motility peristalsis
Relax sphincters
Does this though some direct innervation but also through ENS

FOR BOTH

Question 28

Where do the sacral nerves originate from and what are the names of some of the ganglia they form?

Answer 28

S2-S4 levels leave the spinal cord and form pelvic splanchnic nerves

Hypogastric plexus
myenteric and mucosal plexus

Question 29

What are some of the targets of postgnaglionic sacral fibres? What is there effect

Answer 29

Pelvic viscera
sex organs
urinary bladder
colon

Peristalsis
Increased secretions
Urination contraction of smooth muscle in bladder wall
Deification
Erection

Question 30

What is referred pain

Answer 30

Visceral afferent fibres from viscera enter the dorsal root of the spinal cord and essentially mix with sympathetic afferents coming form the skin that are very nerve cell dense from the same spinal level
The signal mixes with the somatic afferents and triggers then to fire action potentials
This sends signals to the brain telling it there is pain in an associated dermatome at the same level as the nerve that supplies the viscera

Question 31

What is Raynaud’s syndrome
What is the cause
What is the consequence
What are potential treatments?

Answer 31

Overreaction os the SNS in cold conditions resulting in strong vasoconstriction of arteries supplying digits

Occurs due to cold exposure
results in digits going white due to lack of blood flow then bright red as blood flow returns

Is very painful pins and needles sensations

can results in gangrene of the digits if prolonged

Drugs that inhibit sympathetic activity are required (Adrenergic antagonists)

Question 32

What is Horner’s syndrome?
Why does it occur?
What are the causes?

Answer 32

severe constriction of one of the pupils

This occurs due a lesion in the Sympathetic nervous system that supplies the radial muscles

As such PNS activity dominates only the sphincter pupillae are supplied resulting in meiosis and constriction

Also get loss of sweating on associated side as well as ptosis drooping of the eyelid

Causes include trauma tumours MS spinal coed lesions and stroke