[Muscles] Intrinsic Muscles of the Hand

Question 1

Adductor Pollicis

Answer 1

O: Transverse head - MC III
Oblique head - capitate and bases of 2nd and 3rd MCs
Ins: Converge on sesamoid bone, attach to base of proximal phalanx of thumb and extensor hood of thumb
Inn: Deep branch of ulnar nerve
Bs: Deep palmar arterial arch
Action: Adducts thumb

Question 2

Lumbricals (4 muscles)

Answer 2

O: Tendons of flexor digitorum profundis
Ins: Lateral sides of hoods of the extensor
Inn: Lumbricals 2 & 3 - Median nerve
Lumbricals 4 & 5 - Deep ulnar nerve
Bs: Superficial palmar arterial arch
Action: Flexes MCP joint while extending IP joint

Question 3

Palmar interosseous Muscles (3)

Answer 3

O: palmar surfaces of MC bones of digits 2, 4, 5,
Ins: extensor hoods of index finger, ring finger, little finger
Inn: Deep branch of ulnar nerve
Bs: Palmar metacarpal arterial arch
Action: adduct fingers @ MCP jt (towards middle finger)

Question 4

Dorsal interosseous muscles (4)

Answer 4

O: adjacent sides of MC bones
Ins: extensor hood and base of proximal phalanges of index finger, middle finger, and ring finger
Inn: Deep palmar branch of ulnar nerve
Bs: Dorsal and palmar MC arterial arch
Action: Abducts fingers away from middle finger
Flex fingers at MCP jt