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Question 1

Is V1 sensory or motor or both? Does it have parasympathetic, sympathetic fibres or both?

Answer 1

V1 is sensory
Both parasympathetic and sympathetic fibres hitchhike on it

Note: the parasympathetic fibres actually originally hitchhike onto CN3

Question 2

Is CN3 sensory or motor or both? Does it have parasympathetic, sympathetic fibres or both?

Answer 2

Motor fibres to all four recti, inferior oblique and LPS

Parasympathetic to sphincter pupillae and ciliary body

Question 3

Which two structures does the parasympathetic fibre from CN3 go to?

Answer 3

Sphincter pupillae

Ciliary body

Question 4

Which branch of the oculomotor nerve do the parasympathetic fibres travel along?

Answer 4

Inferior branch of oculomotor nerve

Question 5

Which do the parasympathetic fibres, which travel along the inferior branch of the oculomotor nerve, go to before hitchhiking onto another nerve?

Answer 5

Ciliary ganglion

Question 6

What happens to the parasympathetic fibres from CN3 once they have reached the ciliary ganglion?

Answer 6

From the ciliary ganglion, these parasympathetic fibres now hitchhike onto the ciliary nerve of V1

Question 7

What else hitchhikes onto the ciliary nerve of V1, besides the parasympathetic fibres?

Answer 7

T1 sympathetic fibres

Question 8

What are the three branches of the V1? State which of these three divisions have further subdivisions

Answer 8

Lacrimal
Frontal - has subdivisions
Nasociliary - has subdivisions

Question 9

What are the subdivisions of the frontal nerve?

Answer 9

Supratrochlear nerve

Supraorbital nerve

Question 10

What are the subdivisions of the nasociliary nerve?

Answer 10

Ciliary branches
Ethmoidal nerve
Infratrochler nerve

Question 11

Where do the preganglionic sympathetic fibres (of the nerves hitchhiking on V1) initially synapse? Name the level

Answer 11

Superior cervical ganglion at level C2

Question 12

Where do the postganglionic fibres travel to, from the superior cervical ganglion?

Answer 12

Carotid plexus

Opthalmic artery

Question 13

Where do the sympathetic fibres travel to from the carotid plexus?

Answer 13

Superior tarsal muscle (via superior branch of CN3)
Dilator pupillae
Blood vessels for the eye

(Last two via ciliary nerves of V1)

Question 14

Parasympathetic fibres of the facial nerve come from which ganglion?

Answer 14

Pterygopalatine ganglion

Question 15

Which two nerves do these parasympathetic fibres of the facial nerve actually hitchhike on, and where do they travel to?

Answer 15

Hitchhike on the:
Zygomaticotermporal branch of V2
THEN
Lacrimal nerve of V1

(to get to lacrimal gland)

Question 16

Where do the parasympathetic fibres of the facial nerve travel to?

Answer 16

Lacrimal glands

Question 17

Which nerve is most likely to be affected by haemorrhage of the internal carotid artery in the cavernous sinus?

Answer 17

CN 6

Question 18

What do the obliques do?

Answer 18

oBliques = aBduction

Question 19

What will happen in oculomotor palsy (think about the parts of the oculomotor nerve)? Explain why (3)

Answer 19

Unopposed actions of CN 4 and 6 therefore the eye will look down and out laterally

Besides the three recti, the LPS will also lose innervation therefore: complete ptosis

Loss of parasympathetic function: 
Dilated pupil (mydriasis)

Question 20

Which part of the oculomotor nerve would be spared in oculomotor palsy and why?

Answer 20

The sympathetic branch would be spared because this hitchhikes onto V1 to supply the dilator pupillae

Question 21

By asking someone to screw their eyes shut, which muscle nerve are you testing?

Answer 21

Orbicularis occuli - facial nerve

Question 22

What two things can you do to test V1?

Answer 22

Corneal reflex

Dermatome testing

Question 23

What is Horner’s syndrome?

Answer 23

Lesion to the upper sympathetic trunk

Question 24

What is Horner’s usually caused by?

Answer 24

Apex lung tumour (Pancoast’s tumour)

Question 25

What are the symptoms of Horner's syndrome?

Answer 25

Anhydrosis Partial ptosis Miosis (constricted pupil)

Question 26

In terms of ptosis, what would you get if there was lesion to the whole oculomotor nerve?

Answer 26

Complete ptosis

Question 27

Why do you only get partial ptosis in Horner's syndrome?

Answer 27

Because only the superior tarsal muscle is affected, not the LPS which is supplied by CN3.

Question 28

Which artery supplies the orbit and what is this a branch of?

Answer 28

Opthalmic artery, branch of the internal carotid artery

Question 29

What are the branches of the ophthalmic artery?

Answer 29

``` Supratrochlear Muscular Ciliary Supraorbital Lacrimal Central artery of the retina ``` (some men cut soldiers like cheese)