Lab 4

Question 1

What cranial nerves originate from the midbrain?

Answer 1

CN III and IV

Question 2

What cranial nerve originates from the pons?

Answer 2

CN V

Question 3

What cranial nerve originates from the medulla?

Answer 3

CN VI-XIII

Question 4

Identify this structure:

Answer 4

CN II - Optic Nerve

Question 5

Identify this structure:

Answer 5

CN III - Oculomotor Nerve

Question 6

Identify this structure:

Answer 6

CN V - Trigeminal Nerve

Question 7

Identify this structure:

Answer 7

Opthalamic branch of the trigeminal nerve

Question 8

Identify this structure:

Answer 8

Maxillary branch of the trigeminal nerve

Question 9

Identify this structure:

Answer 9

Mandibular branch of the trigeminal nerve

Question 10

Identify this structure:

Answer 10

CN VI- abducent nerve

Question 11

Identify this structure:

Answer 11

CN VII - Facial nerve

Question 12

Identify this structure:

Answer 12

CN VIII - Vestibulocochlear nerve

Question 13

Identify this structure:

Answer 13

CN IX - Glossopharyngeal nerve

Question 14

Identify this structure:

Answer 14

CN X - Vagus nerve

Question 15

Identify this structure:

Answer 15

CN XI - Accessory nerve

Question 16

Identify this structure:

Answer 16

CN XII - hypoglossal nerve

Question 17

Identify this structure:

Answer 17

pons

Question 18

Identify this structure:

Answer 18

pyramid

Question 19

Identify this structure:

Answer 19

trapezoid body

Question 20

Identify this structure:

Answer 20

pyramidal decussation

Question 21

If the trigeminal nerve is lesioned, what reflexes will be absent?

Answer 21

palpebral, corneal, or third eyelid reflex

Question 22

If the abducent nerve is lesioned, what reflex will be absent?

Answer 22

3rd eyelid

Question 23

If the facial is lesioned, what reflex will be absent?

Answer 23

palpebral, corneal, blinking

Question 24

Identify this structure:

Answer 24

fourth ventricle

Question 25

Identify this structure and what is its function?

Answer 25

pontine nucleus of the trigeminal; sensory nucleus for touch and vibration

Question 26

Identify this structure:

Answer 26

motor nucleus of the trigeminal

Question 27

Identify this structure:

Answer 27

trigeminal nerve

Question 28

If there is a lesion to the opthalamic of the trigeminal nerve, what reflex test would you use?

Answer 28

corneal and palpebral

Question 29

If there is a lesion on the motor nucleus of the trigeminal, what reflex tests would you use to localise it?

Answer 29

you wouldn’t really use one, the jaw would just be slacked

Question 30

The right eye does not blink spontaneously. What specific neurological test(s)/observations allow you to localize the lesion?

Answer 30

facial would be damaged - 3rd eyelid test (corneal)

Question 31

Both eyes blink spontaneously, but touching the right medial canthus fails to induce blinking. Where is the lesion?

Answer 31

on the trigeminal

Question 32

Touching the nose usually triggers the animal to pull back the head. If the animal shows no problem moving the head, but does not respond to touching the nose, what nerve(s) could be injured?

Answer 32

the maxillary of the trigeminal

Question 33

Explain why a middle ear infection could develop to facial palsy and a blinking problem.

Answer 33

The facial nerve innervates the stapedius muscle of the middle ear, the infection could follow the facial nerve and affect the other things that it was innervating like the eye and muscles of facial expression

Question 34

Where might the lesion be in a dog that shows a lateral deviation of the tongue to the left?

Answer 34

left hypoglossal

Question 35

When a meningioma involves the orbital fissure, what clinical signs would you expect to see?

Answer 35

no 3rd eyelid response, no corneal response, no palpebral response, lateral and medial strabismus because the oculomotor, trochlear, trigeminal, and abducent pass through