ANS

Question 1

What is the ANS and what does it supply?

Answer 1

Part of the PNS that controls SM and glands. Controls body functions not under conscious control

Question 2

What is the neurone arrangement of the ANS?

Answer 2

Pre ganglionic -> ganglionic -> post ganglionic

Question 3

Where do symp nerves arise from?

Answer 3

Thoracolumbar SC (T1-L2)

Question 4

Where do parasymp nerves arise from?

Answer 4

The brainstem (cranial) and sacral (S2-4)

Question 5

What are the actions of the symp NS?

Answer 5

“Fight or flight”: vasoconstriction, eyelid retraction (tarsal muscle), iris dilator (dilator pupillae), stim sweat glands and arrector pili, decrease lacrimal and salivary secretions

Question 6

What are the functions of the parasymp NS?

Answer 6

“Rest and digest”: sphincter pupillae (constricts) and ciliary body, stimulates lacrimal, salivary and mucosal glands

Question 7

What do symp fibres mostly hitchhike on?

Answer 7

Blood vessels and branches of CNS

Question 8

What is the anatomical course of the symp nerves?

Answer 8

SC -> symp chain -> cervical ganglion -> hitchhike on carotid plexus and breaches of CNS -> SM/glands

Question 9

What two anatomical relations are important to symp nerves? Why?

Answer 9

Carotid arteries and lung apex. E.g pancoast tumour

Pathology here can -> AN dysfunction in eye and face

Question 10

What are the presenting features of Horner’s Syndrome? Why does it occur? What are 2 causes?

Answer 10

Miosis, partial ptosis, +/- anhydrosis.
Occurs due to disruption to symp nerve supply to H and N.
Apical lung tumour, carotid artery dissection (neck pain) disrupt it

Question 11

What are the 2 ganglia of the symp NS?

Answer 11

Sup cervical and middle cervical

Question 12

Which CNs carry parasymp fibres?

Answer 12

Occulomotor, facial, glossopharyngeal, vagus (3,7,9,10)

Question 13

What are the 4 parasymp ganglion called? Wha do they all hitchhike on?

Answer 13

Ciliary, perygopalatine, submandibular, otic.

Hitchhike onto one of the 4 CNs then ganglia then ALL hitchhike on a branch of the trigeminal

Question 14

What is the course of the parasymp oculomotor nerve?

Answer 14

Edinger Westphal nucleus, fibres hitchhike onto OM nerve to ciliary ganglion then on opthalmic (trigeminal) to EYE: ciliary body, sphincter pupillae

Question 15

Parasymp fibres hitchhike on which two branches of the facial nerve?

Answer 15

Chords tympani an greater petrosal

Question 16

Which ganglion do the parasymp fibres hitchhiking on chorda tympani go to? What do they innervate?

Answer 16

Submandibular -> hitchhike on trigeminal to submandibular and sublingual salivary glands

Question 17

Which ganglion do the parasymp fibres hitchhiking on greater petrosal go to? What do they innervate?

Answer 17

Pterygopalatine ganglion -> hithhike on trigeminal to lacrimal, nasal and oral mucosal glands

Question 18

What is the difference between pathology in the facial nerve before and after the geniculate ganglion?

Answer 18

Pathology at or before may involve all parasymp functions (eye fine, dry mouth and loss of muscles of mastication).
After will not involve greater petrosal (lacrimal spared)

Question 19

Which ganglion do the parasymp fibres hitchhiking on glossopharyngeal nerve go to? What do they innervate?

Answer 19

Tympanic nerve and lesser petrosal carry parasymp fibres. Go to otic ganglion then to parotid gland via mandibular (trigeminal)

Question 20

Where do the parasymp fibres hitchhiking on vagus nerve go to? What do they innervate?

Answer 20

Hitchhike on trigeminal then to thorax, abdomen, glands in larygopharynx, larynx, oesophagus and trachea