NBME 21 Inferior rectus and inferior oblique (NBME Answers)

NBME 21 Answers ↦

nbme21/Block 2/Question#34 (49.4 difficulty score)
A 28-year-old man is brought to the emergency ...
Inferior rectus and inferior oblique🔍
tags:

+16
submitted by dr_jan_itor(70),

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oOnpti A is the lnoy noopti hewre htob scumels are part of het obtrila slorf.o,ol A eht alts encnetse in eth iosnuqte tmse is a ttaol emiyofdr fo what neo wudlo xpecet eht usqteino ot eb gink.as tI si ton kanisg ofr uoy ot saumes ttha sethe uclmses vhae been esvedre, dlzarpeya, or eddnrree afdlic. It is sgakin uoy ot smusae hatt eyth aveh bmeceo pete"anpd"r fi het meulcs si endretp,ap ehnt ti actonn lloaw hte eey ot omev otni aeewtvhr soitopin it dowlu eb in ehwn teh semluc is ta ist nelethengd oinist.op So in stih eca,s It is teh eironfri trcues bngie ertppnaed ni a flaciuntnyol dethsreon pooitsin ttah si eipgtenrvn wdrapu z.aeg

cjdinurdreamz im confused...doesnt the IR make the eye look down so if its trapped then why is upward gaze affected and not downward? +

nutmeg_liver @cjdinurdreamz it does make your eye look down, so since it's trapped in a functionally shorter position you're trapped looking down, not up. +2

+4
submitted by soph(55),

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sti cb shti ear hte lyon 2 sescuml no eth ltabior rloof o ggelo toalibr loorf mseclus ni lgegoo esgmai sarNioob&pi:PolOc//rmhm.qElNw:hcFwgg1ustt=a./casshNLwReoe?=e#clscbtmtMOmrgu=+i

+2
submitted by burak(52),

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brlitaO lforo ufate:rrc

-1 ablinrorItaf nvree nuj:riy uNmesbsn nda asrastihpee of hte puper hkc,ee perpu l,ip ppuer vigigna.

-2 nmpneatrEt fo eth iroefinr sretuc elc:ums dirpImea rupwda eazg

-3 iospltsmnoEha

4- lgnuCosi of lxiaralym siu:sn rpaoTdre gnsi

minion7 if IR muscle is affected it is impaired downward gaze!!! +

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. +4

+1
submitted by sympathetikey(1265),

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Iorirfne iequolb = shelp yuo olko up &m;ap i.n

s,oAl ehty dsia rloof of teh iot,rb so it mesak nsese taht hte ieonirrf lseucms oluwd mdg.deaa

sahusema I 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 +5

emmy2k21 Agreed. Why would a dysfunctional inferior rectus contribute to impaired upward gaze??? I eliminated that answer choice and got it wrong :( +2

dr_jan_itor in 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. +14

chandlerbas bam! dr_jan_itor just cleaned up that confusion +1

-1
submitted by niboonsh(338),

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hTe elousibq do hte oopstiep tnicao of retih na.me oIfreirn leiqobu omsev eht eey UP nda UTO oitorxt,n(e iovaentel, dctAniu.oB) neicS eth uotqiens sasy htta eethr is a ferarcut iovnvglin the abtrloi o,rfol hatt ailottyaumcla ulrse uot D laie(md rtecsu nda ieifnror eqobli,u) elgivna eht oynl laolcig resnwa to eb the ferrnoii turcse dan oiifrern bqio.elu ohtow?tcwHkys/WWp.=wuevauc//bKhWtwmIt.DIE:l

aishu007 hi, but inferior oblique moves up and in and not out +

d_holles https://www.youtube.com/watch?v=3J2UZiLVZKA In case ppl need a refresher +