Autonomic Nervous System

Question 1

What are the two divisions of the ANS?

Answer 1

Parasympathetic

Sympathetic

Question 2

How is parasympathetic outflow described?

Answer 2

Craniosacral

Question 3

How is sympathetic outflow described?

Answer 3

Thoracolumbar

Question 4

Where does parasympathetic outflow come from?

Answer 4

CN III
CN VII
CN IX
CN X

S2-4 - pelvic splanchnics

Question 5

Where does sympathetic outflow come from?

Answer 5

T1-L2

Lateral horn of the grey matter in spinal cord

Question 6

What are the actions of the sympathetic system in the head and neck?

Answer 6

Smooth muscle

• blood vessels
• eye lid (tarsal)
• iris (dilator pupillae)

Sweat glands

Arrector pili muscles

Decreases salivary/lacrimal secretions

Question 7

What are the actions of the parasympathetic system in the head and neck?

Answer 7

Smooth muscle

• iris (sphincter pupillae)
• ciliary body muscle

Lacrimal gland

Salivary + mucosal glands

Question 8

Describe the sympathetic flow

Answer 8

Exits spinal cord

Ascends sympathetic chain

Synapses at superior cervical ganglion

Follows the internal and external carotid arteries

External carotid supplies face and neck

Internal carotid becomes ophthalmic artery and supplies oribit

Follows cranial nerves in orbit to supply eye/eyelid

Question 9

What is the clinical relevance of the sympathetic flow?

Answer 9

Passes over apex of lung - pathologies can cause horners syndrome

Question 10

What is horner’s syndrome?

Answer 10

Loss of sympathetic supply to head and neck

Often due to lung apex or internal carotid pathologies

Question 11

What are the signs of Horner’s syndrome?

Answer 11

Unequal pupils
Miosis = loss of dilator pupillae
Partial ptosis
Anhydrosis

Question 12

Describe the parasympathetic flow

Answer 12

Arise from brainstem - parasympathetic nuclei

Hitch-hike of CNs

Ganglia

Hitch-hike on branches of CN V

Target tissues

Question 13

What are the parasympathetic nuclei?

Answer 13

Edinger Westphal
Superior salivary
Inferior salivary
Dorsal motor

Question 14

What are the ganglia?

Answer 14

Ciliary
Submandibular
Pterygopalatine
Otic

Question 15

What cranial nerve is associated with Edinger Westphal nucleus?

Answer 15

CN III

Question 16

What ganglion is associated with CNIII?

Answer 16

Ciliary

Question 17

What cranial nerve is associated with the superior salivary nucleus?

Answer 17

CN VII

Question 18

What ganglions are associated with CN VII?

Answer 18

Submandibular

Pterygopalatine

Question 19

What cranial nerve is associated with the inferior salivary nucleus?

Answer 19

CN IX

Question 20

What ganglion is associated with CN IX?

Answer 20

Otic

Question 21

What cranial nerve is associated with the dorsal motor ganglion?

Answer 21

CN X

Question 22

What is the parasympathetic flow of CN III?

Answer 22

Edinger Westphal nucleus

CNIII

Ciliary ganglion

Eyes

• ciliary body
• constrictor pupillae

Question 23

What is the parasympathetic flow of CN VII?

Answer 23

Follow 2 main branches - greater petrosal + chorda tympani

Question 24

What ganglia is associated with the greater petrosal nerve?

Answer 24

Pterygopalatine ganglion

Question 25

What ganglia is associated with the chorda tympani?

Answer 25

Submandibular ganglion

Question 26

What is the parasympathetic flow of CN IX?

Answer 26

Exits skull via jugular foramen

Splits into 5 branches

• sensory oropharynx
• taste + sensation of tongue
• carotid sinus
• stylopharyngeus
• tympanic nerve

Follows tympanic nerve

Synapses in otic ganglion

Hitch hike on CN Vc

Parotid gland

Question 27

What is the parasympathetic flow of CN X?

Answer 27

Brainstem

Exits with CN X

Ganglion at or in tissues

Tissues

• laryngopharynx
• larynx
• smooth muscle @ oesophagus
• smooth muscle @ trachea
• heart