Hand I: Ch. 14

Question 1

Palmar aponeurosis

Answer 1

1. superficial layer: longitudinally oriented fibers (pathological thickening here = dupuytren’s contracture)
2. deep layer: transversely oriented fibers
   - located in the mid portion of the palm

Question 2

Fibrous Digital Sheaths

Answer 2

• 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

Question 3

synovial digital sheaths

Answer 3

• bursae wrapped around tendons in digits, allowing the tendon to move: two most robust…

1. radial bursa: bursa of flexor pollicis longus tendon
2. ulnar bursa: common flexor bursa

Question 4

Thenar compartment

Answer 4

1. abductor pollicis brevis
2. Flexor pollicis brevis
3. opponens pollicis

Question 5

Abductor Pollicis brevis

Answer 5

A: abducts thumb (with slight flexion of carpometacarpal joint)

N: median n. (recurrent)

Question 6

Flexor Pollicis Brevis

Answer 6

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

Question 7

Opponens Pollicis

Answer 7

A: oppostion of thumb to digits

N: median n (recurrent)

Question 8

Hypothenar Compartment

Answer 8

abductor/flexor/oponens digiti minimi, branches of ulnar nerve, brnhces of ulnar artery and 5th metacarpal

Question 9

Abductor Digiti Minimi

Answer 9

A: abducts and flexes metacarpophalangeal jint of digiti minimi

N: Ulnar N. (deep branch)

Question 10

Flexor digiti minimi

Answer 10

A: flexes digiti minimi at metacarpophalangeal joint

N: Ulnar N. (deep branch)

Question 11

Opponens digit minimi

Answer 11

A: pulls fifth metacarpal towards thumb during opposition/ when grasping

N: Ulnar N. (deep branch)

Question 12

Central Compartment

Answer 12

• contains structures the lie beneath the palmar aponeurosis:
• superficial palmar arterial arch and branches
• branches of median/ulnar nerves
• tendons and ulnar bursa
• lumbricals

Question 13

Flexor Digitorum superficialis

Answer 13

distal attachment of long digital flexors on sides of middle phalanx of digits 2-5

Question 14

Flexor digitorum profundus

Answer 14

• palmar surface, base of distal phalanx, digits 2-5

Question 15

Lumbricals

Answer 15

• 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)

Question 16

adductor-interosseous compartment

Answer 16

• deep palmar arterial arch and its branches
• adductor pollicis
• palmar/dorsal interossei
• deep branch of ulnar nerve
• metacarpals 2/3/4

Question 17

Adductor Pollicis

Answer 17

• has oblique and transverse heads

A: adducts thumg

N: Ulnar (deep branch)

Question 18

Palmar Interossei

Answer 18

• 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

Question 19

Dorsal Interossei

Answer 19

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