Question
Action of this muscle marked with C
A. Abduction and intortion
B. Adduction and extortion
C. Adduction and intortion
D. Abduction and extortion
Show Answer
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Correct Answer » C Explanation |
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Ans:C. Adduction and intortion
This muscles is superior rectus
Superior rectus muscle
- It is innervated by the superior division of the oculomotor nerve (Cranial Nerve III).
- In the primary position (looking straight ahead), the superior rectus muscle’s primary function is elevation, although it also contributes to intorsion and adduction.
The extraocular muscles are the six muscles that control movement of the eye and one muscle that controls eyelid elevation (levator palpebrae)
| Muscle | Innervation | Insertion | Neutral position | Adduction | Abduction |
|---|---|---|---|---|---|
| Superior rectus | Oculomotor nerve (superior branch) |
Eye (anterior, superior surface) |
Elevation Intorsion Adduction |
Intorsion Adduction Elevation |
Elevation |
| Inferior rectus | Oculomotor nerve (inferior branch) |
Eye (anterior, inferior surface) |
Depression Extorsion Adduction |
Extorsion Adduction Depression |
Depression |
| Lateral rectus | Abducens nerve | Eye (anterior, lateral surface) |
Abduction | ||
| Medial rectus | Oculomotor nerve (inferior branch) |
Eye (anterior, medial surface) |
Adduction | ||
| Superior oblique | Trochlear nerve | Eye (posterior, superior, lateral surface) |
Intorsion Depression Abduction |
Depression Abduction Intorsion |
Intorsion Abduction Depression |
| Inferior oblique | Oculomotor nerve (inferior branch) |
Eye (posterior, inferior, lateral surface) |
Extorsion Elevation Abduction |
Elevation Abduction Extorsion |
Extorsion Abduction Elevation |
| Levator palpebrae superioris | Oculomotor nerve | Tarsal plate of upper eyelid | Retracts and elevateseyelid |
