Intrinsic Muscles of the Hand

Flexor Pollicis Brevis Action:

Flexion of the MCP joint of the thumb

Flexor Pollicis Brevis Innervation:

Median nerve

Abductor Pollicis Brevis Action:

Thumb abduction

Abductor Pollicis Brevis Innervation:

Median Nerve

Opponens Pollicis Action:

Opposition of the thumb

Opponens Pollicis Innervation:

Median nerve

What are the 3 thenar muscles?

Opponens Pollicis, Abductor Pollicis Brevis, & Flexor Pollicis Brevis

Adductor Pollicis Action:

Thumb adduction

Adductor Pollicis Innervation:

Ulnar nerve

Dorsal Interossei PA:

Adjacent sides of all metacarpals

Dorsal Interossei DA:

Base of the proximal phalanges

Dorsal Interossei Action:

Abduction of the MCP joints of digits 2-4

Dorsal Interossei Innervation:

Ulnar nerve

Palmar Interossei PA:

Metacarpals

Palmar Interossei DA:

Base of the proximal phalanges

Palmar Interossei Action:

Adduction of the MCP joints of the 2nd, 4th, and 5th digits

Palmar Interossei Innervation:

Ulnar nerve

Lumbricals PA:

Tendons of the flexor digitorum profundus

Lumbricals DA:

Lateral band of the extensor mechanism of the fingers and extensor digitorum tendon

Lumbricals Action:

Flexion of the MCP joint and extension of the PIP and DIP joints of the fingers

Lumbricals Innervation:

Medial two: Ulnar nerve & Lateral two: Median nerve

Flexor Digiti Minimi Innervation:

Ulnar nerve

Flexor Digiti Minimi Action:

Flexion of the MCP joint of the small finger

Abductor Digiti Minimi Action:

Abduction of the MCP joint of the small finger

Abductor Digiti Minimi Innervation:

Ulnar Nerve

Opponens Digiti Minimi Action:

Opposition of the CMC joint of the small finger

Opponens Digiti Minimi Innervation:

Ulnar nerve

What are the 3 hypothenar muscles?

Flexor Digiti Minimi, Abductor Digiti Minimi, & Opponens Digiti Minimi

The ulnar nerve innervates these muscles:

Adductor Pollicis, Dorsal Interossei, Palmer Interossei, Medial 2 Lumbricals, & all 3 hypothenar muscles

The median nerve innervates these muscles:

All 3 thenar muscles & the lateral two lumbricals