need help with your account or subscription? click here to email us (or see the contact page)
join telegramNEW! discord
jump to exam page:
search for anything ⋅ score predictor (โ€œpredict me!โ€)

Retired NBME 16 Answers

nbme16/Block 4/Question#41 (reveal difficulty score)
A 23-year-old woman, who was diagnosed with ...
Substance P ๐Ÿ” / ๐Ÿ“บ / ๐ŸŒณ / ๐Ÿ“–
tags:

 Login (or register) to see more


 +6  upvote downvote
submitted by โˆ—okokok1(38)
get full access to all contentpick a username

ฮณ-aminobutyric acid =GABA, so not a neurotransmitter dealing with pain. deals with excitability and movement.

dopamine: think of parkinson's (too little of it) and schizophrenia (too much of it), either way doesn't deal with pain reception.

Enkephalin: related to a type of opioid receptor. It closes presynaptic Ca2+ channels, open postsynaptic K+channelsย and thus decreases synaptic transmission. It actually inhibits the release of ACh, norepinephrine, 5-HT, glutamate, substance P.

Serotonin: think of depression. again, doesnt deal with pain reception.

Substance P: even if you didn't know exactly what it did, you could rule out the others. you could also remember the pathophysiology of migraines: "Due to irritation of CN V, meninges, or blood vessels (release of vasoactive neuropeptides [eg, substance P, calcitonin gene-related peptide]) causing the immense pain of migraines."

For completeness sake: "Muscle nociceptors contain neuropeptides, including substance P (SP) and calcitonin-gene-related peptide (CGRP). These peptides are released when nerve endings are activated and induce local edema by dilating the local blood vessels and increasing their permeability." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2696782/

also, good to know aprepitant is an anti-emetic that is Substance P antagonist. Blocks NK1(neurokinin-1) receptors in brain. yes, theres no mention of "pain" in that FA definition but Substance P got its hands in a lot of cookie jars ok

get full access to all contentpick a username



 +5  upvote downvote
submitted by โˆ—mkenerly(11)
get full access to all contentpick a username

Capsaicin cream treats neuropathic pain by depleting substance P in the localized area. Since there was partial relief after administration of capsaicin, substance P is most likely mediating this patient's pain.

get full access to all contentpick a username



Must-See Comments from nbme16

bingcentipede on Cerebral edema
zincy7 on Gastrin
cassdawg on Kidney
medninja on Lysosomes
cassdawg on Sildenafil
cassdawg on Feces-contaminated soil
cassdawg on Presence of an internal ribosome entry site
cassdawg on Peutz-Jeghers
hungrybox on Induction of cytochrome P450 enzymes that ...
andro on Antagonizes VLDL-cholesterol secretion
bingcentipede on Decreased function of Na+โ€“K+ ATPase
bingcentipede on Glyceraldehyde-3-phosphate dehydrogenase
cassdawg on 46,XXY
bingcentipede on Grade 4/6, holosystolic murmur heard best ...

search for anything NEW!