Medial Rectus And Inferior Oblique Dmg


The medial rectus, inferior rectus and inferior oblique nuclei connect to the ipsilateral muscle. The motor nuclei are distributed along the nucleus with three subgroups for the medial rectus. The levator palpebrae nuclei supplies both ipsilateral and contralateral function from a midline subnucleus. 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. 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.

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.



Medial Rectus And Inferior Oblique Dmg
+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


Medial Rectus And Lateral Rectus

The medial rectus is a muscle located in the eye socket. This muscle works within a sort of pulley-system and, along with other extraocular muscles, helps to control certain movements of the eye. The role of the medial rectus in eye movement is that of adduction. That is to say, the eye moves in an inward direction, as toward the nose. Several medical conditions have the potential to compromise the function of this important muscle of the eye.

The nerve supply to the medial rectus muscle is provided by the oculomotor nerve, also referred to as the third cranial nerve. While working to control the majority of the movements of the eye itself, this nerve provides other functions as well. The oculomotor nerve is also responsible for holding the eyelid in an open position in addition to constricting the pupil.

Medial rectus palsy is a medical condition known to have an adverse effect on the medial rectus muscle. This condition occurs frequently when there has been a traumatic brain injury. The damage to the oculomotor nerve causes nerve and sometimes muscle paralysis. Improper eye movement and double vision are typical symptoms of this condition. Medications are sometimes helpful in alleviating troubling symptoms, although surgical intervention is sometimes necessary.

Esotropia is another condition affecting the medial rectus muscle. In this condition, the patient exhibits what is commonly referred to as a squint. What this means is that the eye, or sometimes both eyes, turn in an inward position. This is commonly known as being cross-eyed. A surgical procedure called medial rectus recession is often employed in an attempt to correct this condition.

Medial Rectus Eye

Medial wall fractures sometimes occur when there has been some sort of facial trauma. This type of fracture is another common cause of damage to the medial rectus muscle. The orbital floor is normally affected along with the medial wall itself. Swelling and skin discoloration are often the only outward signs that this type of fracture has occurred. While symptoms sometimes resolve on their own, surgery is very often required.

Medial Rectus And Inferior Oblique Dmg Muscles

An abnormal muscle thickness involving the medial rectus is sometimes found in a patient with Grave's Disease, although it can be present with no sign of disease. This condition causes pain as well as impaired vision. The use of medications such as eye drops along with the use of a humidifier is often enough to relieve troublesome symptoms in those with mild cases of this condition. Radiation or surgery are only necessary modes of treatment in rare cases which do not respond to more conservative treatments.