Because I was reading Robert Frost (“The Road Not Taken”) instead of studying for Gross Anatomy

Two nerves diverge in a withered hand
And sorry I cannot select the pair
Just one answer – so I stand
My palms sweaty, expression’s bland
Under the proctor’s icy stare

The first one’s got a yellow hue
And shines beneath fluorescent light
Myelin sheath is holding true
That once sped signals out of view
Through carpal tunnel and out of sight

The other nerve, so too it lay
Yellow, glossy, full of charm
A bit smaller, but who’s to say
Less important if it could convey
Its messages up and down the arm

Time’s up, the alarm’s about to wail
I suppose that I will have to guess
Hours of studying to no avail
If the margin between pass and fail
Is median or ulnar, ’cause it makes all the difference.