Wrist extensors are primarily controlled by what nerve?

The correct answer is A. Radial. Radial nerve (A) innervates all the wrist and finger extensors via its deep branch (posterior interosseous nerve), making it the primary motor nerve for wrist extension. Why the distractors are wrong: B. Ulnar - controls intrinsic hand muscles (hypothenar, interossei, medial…

Normal Structure and Function

Question

Options

ARadial
BUlnar
CMedian
DTibial

How the community answered

(69 responses)

A
71% (49)
B
4% (3)
C
9% (6)
D
16% (11)

Explanation

Radial nerve (A) innervates all the wrist and finger extensors via its deep branch (posterior interosseous nerve), making it the primary motor nerve for wrist extension.

Why the distractors are wrong:

B. Ulnar - controls intrinsic hand muscles (hypothenar, interossei, medial two lumbricals) and flexor carpi ulnaris; not extensors
C. Median - innervates most forearm flexors and thenar muscles; no wrist extensors
D. Tibial - a lower-limb nerve entirely; irrelevant to the wrist

Memory tip: Think "Radial = Raise your wrist" - the radial nerve runs along the radial (thumb) side of the forearm and controls all extension. Damage to the radial nerve causes classic "wrist drop," which is the loss of extension.

Topics

#Radial nerve#Wrist extensors#Peripheral nerve innervation#Upper extremity anatomy

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