Hand I: Ch. 14 Flashcards
Palmar aponeurosis
- superficial layer: longitudinally oriented fibers (pathological thickening here = dupuytren’s contracture)
- deep layer: transversely oriented fibers
- located in the mid portion of the palm
Fibrous Digital Sheaths
- form fibro-osseous canals for passage of digital flexor tendons
- these canals prevent “bowstringing” of flexors during flexion
- synovial digital sheaths lubricate the sheat and the tendon
synovial digital sheaths
- bursae wrapped around tendons in digits, allowing the tendon to move: two most robust…
- radial bursa: bursa of flexor pollicis longus tendon
- ulnar bursa: common flexor bursa
Thenar compartment
- abductor pollicis brevis
- Flexor pollicis brevis
- opponens pollicis
Abductor Pollicis brevis
A: abducts thumb (with slight flexion of carpometacarpal joint)
N: median n. (recurrent)
Flexor Pollicis Brevis
A: flexion of thumb at carpometacarpal joint and metacarpal phalangeal joint
N: superficial head: median n. (recurrent); deep head: deep branch ulnar n.
NOTE: sesamoid bone can usually be found within the course of this muscle
Opponens Pollicis
A: oppostion of thumb to digits
N: median n (recurrent)
Hypothenar Compartment
abductor/flexor/oponens digiti minimi, branches of ulnar nerve, brnhces of ulnar artery and 5th metacarpal
Abductor Digiti Minimi
A: abducts and flexes metacarpophalangeal jint of digiti minimi
N: Ulnar N. (deep branch)
Flexor digiti minimi
A: flexes digiti minimi at metacarpophalangeal joint
N: Ulnar N. (deep branch)
Opponens digit minimi
A: pulls fifth metacarpal towards thumb during opposition/ when grasping
N: Ulnar N. (deep branch)
Central Compartment
- contains structures the lie beneath the palmar aponeurosis:
- superficial palmar arterial arch and branches
- branches of median/ulnar nerves
- tendons and ulnar bursa
- lumbricals
Flexor Digitorum superficialis
distal attachment of long digital flexors on sides of middle phalanx of digits 2-5
Flexor digitorum profundus
- palmar surface, base of distal phalanx, digits 2-5
Lumbricals
- different from all other muscles because no bony attachments, just tendons
- precise “a-ok” movement
- originate on profundus tendons and insert on digitorum tendons
A: flexes metacarpophalangeal joints and extends interphalangeal joints
N: median (lumbricles 1/2), ulnar (lumbricals 3/4)
adductor-interosseous compartment
- deep palmar arterial arch and its branches
- adductor pollicis
- palmar/dorsal interossei
- deep branch of ulnar nerve
- metacarpals 2/3/4
Adductor Pollicis
- has oblique and transverse heads
A: adducts thumg
N: Ulnar (deep branch)
Palmar Interossei
- multipennate
- “P-ad”: palmar adducts
A: adducts digits 1,2,4,5, flexes MP joints and extends IP joints of 1,2,4,5
N: deep ulnar branch
Dorsal Interossei
bipennate, stronger!
- “d-ab” dorsal abducts
A: abducts digits w,e,r, flexes MP joints and extends IP joints of digits 2,3,4
N: Ulnar deep branch
