Medial Rectus And Inferior Oblique Dmg

The medial rectus muscle is one of the 6 extraocular muscles that control eye movements. Summary innervation: inferior branch of the oculomotor nerve (CN III) origin: annulus of Zinn (tendinous ring) insertion: globe (anterior, medial surface. The inferior branch supplies the medial rectus, inferior rectus and inferior oblique. This inferior branch also gives off most of the anterior ciliary arteries. Note: Anastomoses to the periorbit are also formed via the facial and superficial temporal branches of the external carotid.

The superior rectus, a bilateral rostrocaudal arrangement for the medial rectus and inferior oblique, and a contralateral, caudal position for the inferior rectus subnuclei. It also conflicts with the reports of both Danis (10) and Szentogathai (21) who, using focal stimulation to. Typical space from limbus is: Medial rectus, 5 millimeters Inferior rectus, 6 millimeters Lateral rectus, 7 millimeters Superior rectus, 8 millimeter. Oblique Muscles. The oblique muscles of the orbit are superior and inferior. Their origin and insertion are as follows: Superior Oblique. Origin: from body of sphenoid superomedial to the optic. A 6-year-old boy who had been treated with bilateral medial rectus muscle recessions 3 years earlier for congenital esotropia was undergoing bilateral inferior oblique muscle recessions to correct inferior oblique muscle overaction. The right inferior rectus muscle was inadvertently cut during this surgery and was irretrievable. To manage this complication, the medial rectus.


NBME 21 Answers ↦
nbme21/Block 2/Question#34
A 28-year-old man is brought to the emergency ...
Inferior rectus and inferior oblique🔍
+13 upvotedownvote
submitted by dr_jan_itor(55), 2019-08-02T19:26:29Z

Option A is the only option where both muscles are part of the orbital floor.Also, the last sentence in the question stem is a total modifyer of what one would expect the question to be asking. It is not asking for you to assume that these muscles have been severed, paralyzed, or rendered flacid. It is asking you to assume that they have become 'entrapped' if the muscle is entrapped, then it cannot allow the eye to move into whatever position it would be in when the muscle is at its lengthened position. So in this case, It is the inferior rectus being entrapped in a functionally shortened position that is preventing upward gaze.



+4 upvotedownvote
submitted by soph(45), 2019-07-27T01:49:30Z

its bc this are the only 2 muscles on the orbital floor google orbital floor muscles in google imageshttps://www.google.com/search?q=orbital+muscles&tbm=isch#imgrc=NNOONaLRFuEP1M:



+2 upvotedownvote
submitted by burak(37), 2019-08-07T20:26:07Z

Orbital floor fracture:

1- Infraorbital nerve injury: Numbness and paresthesia of the upper cheek, upper lip, upper gingiva.

2- Entrapment of the inferior rectus muscle: Impaired upward gaze

3- Enophtalmosis

4- Clousing of maxillary sinus: Teardrop sign

minion7if IR muscle is affected it is impaired downward gaze!!!+2019-12-01T11:24:56Z
makinallkindzofgainz@minion7, If the Inferior Rectus muscle is impaired (e.g. nerve dysfunction), then yes, downward gaze would be affected. However, the question states that there is ENTRAPMENT of muscles. Trapping the inferior rectus muscle essentially locks the eye into a downward gaze, therefore impairing upward gaze, as the inferior rectus muscle is essentially trapped in contraction.+22020-01-18T16:38:19Z


+1 upvotedownvote
submitted by sympathetikey(816), 2019-06-12T22:43:34Z

Inferior oblique = helps you look up & in.

Also, they said floor of the orbit, so it makes sense that the inferior muscles would damaged.

sahusemaI know you're right. I was just so uncomfortable picking an answer with 'inferior rectus' because damage to the inferior rectus does nothing to explain the clinical findings of impaired upward gaze. Unless the muscle is physically stuck and can't relax or something+52019-07-19T16:30:57Z
emmy2k21Agreed. Why would a dysfunctional inferior rectus contribute to impaired upward gaze??? I eliminated that answer choice and got it wrong :(+12019-07-21T01:01:43Z
dr_jan_itorin the last sentence it asks you to assume an 'entrapment', so it is actually the inferior rectus which is the cause of the upward gaze palsy. The entrapped muscle is functionally trapped in it's shortened position, thereby not allowing the orbit to gaze upward. +112019-08-02T19:23:40Z
chandlerbasbam! dr_jan_itor just cleaned up that confusion +2019-11-09T22:59:38Z


-1 upvotedownvote
submitted by niboonsh(241), 2019-06-24T02:08:49Z

The obliques do the opposite action of their name. Inferior oblique moves the eye UP and OUT (extortion, elevation, ABduction). Since the question says that there is a fracture involving the orbital floor, that automatically rules out D (medial rectus and inferior oblique), leaving the only logical answer to be the inferior rectus and inferior oblique. https://www.youtube.com/watch?v=lWKkHWWDIEI

aishu007hi, but inferior oblique moves up and in and not out+2019-06-30T10:43:12Z
d_holleshttps://www.youtube.com/watch?v=3J2UZiLVZKA In case ppl need a refresher +2019-07-01T22:41:00Z

Medial Rectus Function




NBME 21 Answers ↦
nbme21/Block 2/Question#34
A 28-year-old man is brought to the emergency ...
Inferior rectus and inferior oblique🔍
+13 upvotedownvote
submitted by dr_jan_itor(55), 2019-08-02T19:26:29Z

Option A is the only option where both muscles are part of the orbital floor.Also, the last sentence in the question stem is a total modifyer of what one would expect the question to be asking. It is not asking for you to assume that these muscles have been severed, paralyzed, or rendered flacid. It is asking you to assume that they have become 'entrapped' if the muscle is entrapped, then it cannot allow the eye to move into whatever position it would be in when the muscle is at its lengthened position. So in this case, It is the inferior rectus being entrapped in a functionally shortened position that is preventing upward gaze.



+4 upvotedownvote
submitted by soph(45), 2019-07-27T01:49:30Z

its bc this are the only 2 muscles on the orbital floor google orbital floor muscles in google imageshttps://www.google.com/search?q=orbital+muscles&tbm=isch#imgrc=NNOONaLRFuEP1M:



+2 upvotedownvote
submitted by burak(37), 2019-08-07T20:26:07Z

Orbital floor fracture:

1- Infraorbital nerve injury: Numbness and paresthesia of the upper cheek, upper lip, upper gingiva.

2- Entrapment of the inferior rectus muscle: Impaired upward gaze

3- Enophtalmosis

4- Clousing of maxillary sinus: Teardrop sign

Medial Rectus And Inferior Oblique Dmg Muscles

minion7if IR muscle is affected it is impaired downward gaze!!!+2019-12-01T11:24:56Z
makinallkindzofgainz@minion7, If the Inferior Rectus muscle is impaired (e.g. nerve dysfunction), then yes, downward gaze would be affected. However, the question states that there is ENTRAPMENT of muscles. Trapping the inferior rectus muscle essentially locks the eye into a downward gaze, therefore impairing upward gaze, as the inferior rectus muscle is essentially trapped in contraction.+22020-01-18T16:38:19Z


+1 upvotedownvote
submitted by sympathetikey(816), 2019-06-12T22:43:34Z

Inferior oblique = helps you look up & in.

Also, they said floor of the orbit, so it makes sense that the inferior muscles would damaged.

sahusemaI know you're right. I was just so uncomfortable picking an answer with 'inferior rectus' because damage to the inferior rectus does nothing to explain the clinical findings of impaired upward gaze. Unless the muscle is physically stuck and can't relax or something+52019-07-19T16:30:57Z
emmy2k21Agreed. Why would a dysfunctional inferior rectus contribute to impaired upward gaze??? I eliminated that answer choice and got it wrong :(+12019-07-21T01:01:43Z
dr_jan_itorin the last sentence it asks you to assume an 'entrapment', so it is actually the inferior rectus which is the cause of the upward gaze palsy. The entrapped muscle is functionally trapped in it's shortened position, thereby not allowing the orbit to gaze upward. +112019-08-02T19:23:40Z
chandlerbasbam! dr_jan_itor just cleaned up that confusion +2019-11-09T22:59:38Z

Medial Rectus And Inferior Oblique Dmg

Medial Rectus And Inferior Oblique Dmg


-1 upvotedownvote
submitted by niboonsh(241), 2019-06-24T02:08:49Z

The obliques do the opposite action of their name. Inferior oblique moves the eye UP and OUT (extortion, elevation, ABduction). Since the question says that there is a fracture involving the orbital floor, that automatically rules out D (medial rectus and inferior oblique), leaving the only logical answer to be the inferior rectus and inferior oblique. https://www.youtube.com/watch?v=lWKkHWWDIEI

aishu007hi, but inferior oblique moves up and in and not out+2019-06-30T10:43:12Z
d_holleshttps://www.youtube.com/watch?v=3J2UZiLVZKA In case ppl need a refresher +2019-07-01T22:41:00Z

Medial Rectus Muscle Function