NBME 23 Fasciculus gracilis (NBME Answers)

Retired NBME 23 Answers

nbme23/Block 1/Question#37 (reveal difficulty score)
A 47-year-old woman with multiple sclerosis ...
Fasciculus gracilis 🔍 / 📺 / 🌳 / 📖
tags:

+7 upvote downvote
submitted by ∗cbrodo(77)

get full access to all content ⋅ pick a username

The posterior columns (Fasciculus cuneatus/Fasciculus gracilis) carry information to the brain regarding proprioception, vibration, discriminative touch and pressure. Physical exam findings suggest a lesion here (the spinothalamic tract carries pinprick/pain and temperature, and these were normal). Since the patient has abnormal findings in the lower extremities, and normal findings in the upper extremities, the answer is Fasciculus gracilis. This is because information from body areas below the level of T6 is carried by gracilis and information from body areas above the level of T6 is carried by cuneatus.

get full access to all content ⋅ pick a username

kai kick Goals (gracilis) with your feet Cook and eat (cuneatus) with your hands +4

temmy i remember gracilis is for legs by saying i have graciously long legs and they are inside while arms can spread out to remember their orientation on the spinal cord +4

jess123 I remember it as gracilis = grass so feet haha +5

link981 Just to add found on page 492 on FA 2018. +

charcot_bouchard Hey Temmy, I can spread my legs too :) +

maxillarythirdmolar I can't feel GRACIE's ~fine touch~ as she ~vibrates~ my balls. +4

cat5280 Could someone please explain why you were able to eliminate the spinocerebellar tracts? +1

drzed Lmao I remember gracilis because of the gracilis muscle in the legs! +3

alexxxx30 cat5280...so spinocerebellar tract does 4 things to know 1. proprioception in the Romberg test 2. intention tremor if damaged 3. shin to knee test 4. dysdiadochokinesia (being able to rapidly pronate/supinate the upper extremity) yes the patient has proprioception issues, but the other symptom of vibration loss points us more to a fasciculus gracilis issue. If the patient had presented with proprioception and and intention tremor then we would think spinocerebellar +3

alexxxx30 adding to my comment^ I would commit these 4 things to memory as I have gotten several questions concerning this topic (there were 2 questions on this exam where spinocerebellar tracts are involved). Memorize them and it might get you 1-2 extra points! +1

solidshake Just to clarify a point, Spinocerebellar tracts are not tested by the Romberg Test. Romberg tests conscious proprioception that is done by the dorsal columns. Spinocerebellar tracts are used for Unconscious proprioception. Look up tabes dorsalis in First Aid. One of the positive indicators is a positive romberg test, which shows that the dorsal columns have been damaged thus affecting conscious proprioception and thus impaired balanced on standing with the eyes closed +2

+2 upvote downvote
submitted by cat5280(3)

get full access to all content ⋅ pick a username

Could someone please explain why you were able to eliminate the spinocerebellar tracts?

get full access to all content ⋅ pick a username

ergogenic22 Spinocerebellar is only responsible for Proprioception (unconscious). This patient also has reduced vibration sensation, which the dorsal column tracts are responsible for. +3

+2 upvote downvote
submitted by ∗abhishek021196(120)

get full access to all content ⋅ pick a username

Dorsal column (pressure, vibration, fine touch, proprioception)

ASCENDING

• Fasciculus graciLis (Lower body, legs) • Fasciculus cUneatus (Upper body, arms)

Dorsal columns are organized as you are, with hands at sides. “Arms outside, legs inside.”

get full access to all content ⋅ pick a username

+0 upvote downvote
submitted by rs888(0)

get full access to all content ⋅ pick a username

Gracillis is a muscle in the lower limb which makes it easy to remember. cUneatus has a U for Upper limb. just something i use.

get full access to all content ⋅ pick a username

Must-See Comments from nbme23

ferrero on Precapillary resistance
yotsubato on 99%
sne on Triglyceride
sajaqua1 on Area labeled ‘D’ (Spinothalamic tract, right)
stinkysulfaeggs on Hypoglycemia
hayayah on Iris
soph on Peak inspiratory pressure (alveolar): ...
seagull on Area labeled ‘C’ (Cranial nerve 8: ...
water on Dietary change
wired-in on 28.8
beeip on Binding of permeable ligand to nuclear ...
thomasalterman on Hypoglycemia
yotsubato on Inhibition of the cytochrome P450-dependent ...
seagull on Decreased sodium bicarbonate reabsorption in ...