SDL 2: Jaw and eye muscles

Question 1

List the 6 muscles involved in the movement of the eye.

Answer 1

Superior rectus
Inferior rectus
Lateral rectus
Medial rectus
Superior oblique
Inferior oblique

Question 2

Which of the extra-ocular muscles are innervated by the oculomotor nerve (CNIII)?

Answer 2

Superior rectus
Inferior rectus
Medial rectus
Inferior oblique

Question 3

Which extra-ocular muscle is innervated by the trochlear nerve (CNIV)?

Answer 3

Superior oblique

Question 4

Which extra-ocular muscle is innervated by the abducens nerve (CNVI)?

Answer 4

Lateral rectus

Question 5

How would you test the function of the oculomotor nerve (CNIII)?

Answer 5

Ask the patient to look medially. Check the upper eyelid is fully retracted on upward gaze.

Question 6

How would you test the function of the trochlear nerve (CNIV)?

Answer 6

Ask the patient to look medially then downwards. Isolated region very rare.

Question 7

How would you test the function of the abducens nerve?

Answer 7

Ask the patient to look laterally.

Question 8

What is the function of the levator palpabrae superior?

Answer 8

Retract the upper eyelid.

Question 9

Which muscle malfunctions during ptosis?

Answer 9

Levator palpebrae superioris

Question 10

What is Horner’s syndrome?

Answer 10

Combination of symptoms that arises when the sympathetic trunk is damaged. The signs and symptoms occur on the same side as the lesion of the sympathetic trunk. It is characterized by miosis (a constricted pupil), ptosis (a weak, droopy eyelid), apparent anhidrosis (decreased sweating), with or without enophthalmus (inset eyeball).

Question 11

Why does mild ptosis occur in Horner’s syndrome?

Answer 11

Loosthe superior tarsal muscle which produces ptosis

Question 12

What are the actions of each of the 6 extra-ocular muscles controlling the eye?

Answer 12

Superior rectus - elevation (primarily - also intorsion and adduction)
Inferior rectus - depression (primarily - also extorsion and adduction)
Lateral rectus - abduction
Medial rectus - adduction
Superior oblique - intorsion, depression and abduction
Inferior oblique - extorsion, elevation and abduction

Question 13

Which two visual reflexes would be absent in a patient with unilateral oculomotor nerve damage. Which other cranial nerve is involved in these reflexes.

Answer 13

Pupillary light reflex
Accommodation reflex
(CNII also involved)

Question 14

What is the role of the ciliary ganglion?

Answer 14

Provides autonomic innervation to the sphincter pupillae constricts the pupil, a movement known as Miosis. The opposite, Mydriasis, is the dilation of the pupil.
Also innervates the ciliaris, causing it to contract, releasing tension on the Zonular Fibers, making the lens more convex, also known as accommodation.

Question 15

Which bony structure acts with the lateral ligament to prevent dislocation of the TMJ?

Answer 15

The articular tubercle

Question 16

Which two other functional ligaments can be found within the TMJ?

Answer 16

Collateral (lateral and medial)
Capsular

NB: Everywhere I look gives different answers and I can’t find the attachments

Question 17

What are the four principle muscles of mastication?

Answer 17

Masseter
Temporalis
Lateral pterygoid
Medial pterygoid

Question 18

Which muscle(s) are responsible for elevation of the mandible (closing the mouth)?

Answer 18

Temporalis
Masseter
Medial pterygoid (minor role)

Question 19

Which muscle(s) are responsible for depression of the mandible (opening the mouth)?

Answer 19

Lateral pterygoid (assisted by digastric)

Question 20

Which muscle(s) are responsible for protrusion of the mandible?

Answer 20

Lateral pterygoid

Question 21

Which muscle(s) are responsible for retrusion of the mandible?

Answer 21

Temporalis

Question 22

Which muscle(s) are responsible for lateral movements of the mandible?

Answer 22

Medial pterygoid

Question 23

What is the nerve supply to the muscles of mastication?

Answer 23

Motor component of the mandibular division of the trigeminal nerve (V3).

Question 24

What foramina does this nerve branch pass through?

Answer 24

Foramen ovale