Hand

Question 1

What’s the most frequently fractured carpal bone?

Answer 1

Scaphoid

Question 2

What’s the most frequently dislocated carpal bone?

Answer 2

Lunate

Question 3

Which wrist bone is found w/in the tendon of the flexor carpi ulnaris?

Answer 3

Pisiform

Question 4

Which wrist bone has a hook-like process and what is it called?

Answer 4

Hamate, hamulus

Question 5

Which carpal bone is the longest & 1st to ossify?

Answer 5

Capitate

Question 6

Which carpal bone has a saddle-shaped facet for the 1st metacarpal and a tubercle for attachment to the flexor retinaculum?

Answer 6

Trapezium

Question 7

What dermatome covers the thenar eminence?

Answer 7

C6

Question 8

What dermatome covers the index and middle finger?

Answer 8

C7

Question 9

What dermatome covers the ring and pinky finger?

Answer 9

C8

Question 10

When the deep palmar fascia reaches the palm, it’s known as the _____. What tendon inserts into it?

Answer 10

• Palmar aponeurosis

- Palmaris longus tendon

Question 11

What causes Dupuytren’s contracture? What are its sx?

Answer 11

• Progressive fibrosis from palmar aponeurosis to base of phalanges
• Pulls digits into flexion at the metacarpo-phalangeal joints (so they can’t be straightened)

Question 12

Tendons of the fingers are surrounded by _________.

Answer 12

Synovial sheaths

Question 13

What are the boundaries of the carpal tunnel?

Answer 13

• Anterior: flexor retinaculum

- Posterior: carpal bones

Question 14

What lies w/in the carpal tunnel?

Answer 14

• 4 tendons of the flexor digitorum superficialis
• 4 tendons of the flexor digitorum profundus
• 1 tendon of flexor pollicis longus
• Median n.

Question 15

What are some possible causes of carpal tunnel syndrome? What n. is affected? What are the sx?

Answer 15

• Fluid retention, infection, excessive exersize
• Median n.
• Wasting of the thenar mm. (can’t oppose thumb)

Question 16

What mm. are in the thenar compartment of the hand and what are they innervated by?

Answer 16

• OAF:
  1. Opponens pollicis m.
  2. Abductor pollicis brevis m.
  3. Flexor pollicis brevis m.
• Median n. (recurrent branch)

Question 17

What mm. are in the hypothenar compartment of the hand and what are they innervated by?

Answer 17

• OAF:
  1. Opponens digiti minimi m.
  2. Abductor digiti minimi m.
  3. Flexor digiti minimi brevis m.
• Ulnar n.

Question 18

Adductor pollicis m. innervation and action?

Answer 18

• Ulnar nerve (deep branch)

- Adducts thumb

Question 19

Abductor digiti minimi m. innervation and action?

Answer 19

• Ulnar nerve (deep branch)

- Adducts little finger

Question 20

Flexor digiti minimi brevis m. innervation and action?

Answer 20

• Ulnar nerve (deep branch)

- Flexes proximal phalanx of little finger

Question 21

Opponens digiti minimi m. innervation and action?

Answer 21

• Ulnar n. (deep branch)

- Draws 5th metacarpal anteriorly and rotates it to face thumb

Question 22

Dorsal interosseous mm. (DABs) innervation and action?

How many are there?

Answer 22

• Ulnar n. (deep branch)
• Abducts digits from axial line of hand (3rd digit), flexes digits at metacarpo-phalangeal joints, extends interphalangeal joints
• There are 4 (2 on middle, pinky has it’s own abductor so none on pinky)

Question 23

Palmar interosseous mm. (PADs) innervation and action?

How many are there?

Answer 23

• Ulnar n. (deep branch)
• Abducts digits from axial line of hand (3rd digit), flexes digits at metacarpo-phalangeal joints, extends interphalangeal joints
• There are 3 (none on middle finger)

Question 24

Lumbrical mm. (1st and 2nd) innervation and action?

Answer 24

• Medial n. (digit branches)

- Extends digits at interphalangeal joints, flexes at metacarpo-phalangeal joints (can touch pulp of fingers)

Question 25

Lumbrical mm. (3rd and 4th) innervation and action?

Answer 25

- Ulnar n. (deep branch) | - Extends digits at interphalangeal joints, flexes at metacarpo-phalangeal joints (can touch pulp of fingers)

Question 26

Palmaris brevis m. innervation and action?

Answer 26

- Superficial palmar branch of ulnar n. | - Deepens hollow of hand, assists grip

Question 27

Abductor pollicis brevis m. innervation and action?

Answer 27

- Medial n. (recurrent branch) | - Abducts thumb

Question 28

Opponens pollicis m. innervation and action?

Answer 28

- Median n. (recurrent branch) | - Draws 1st metacarpal forward and rotates it medially

Question 29

What is the basic arterial supply to the hand?

Answer 29

-USRD: Ulnar a. superficial, radial a. deep

Question 30

What happens to the ulnar a. once it enters the hand?

Answer 30

- Divides into superficial branch and deep brach of ulnar a. - Superficial branch then becomes superficial palmar arch (gives off common palmar digital and proper palmar digital aa. as it moves across hand)

Question 31

Where are the common palmar aa.?

Answer 31

-Pass b/w metacarpals (comes from superficial branch of ulnar a.)

Question 32

Where are the proper palmar digital aa.?

Answer 32

-Run on either side of digits 2-5 (comes from superficial branch of ulnar a.)

Question 33

Where is the deep branch of ulnar a.?

Answer 33

- Passes b/w abductor digiti minimi and flexor digiti minimi mm. - Anastomoses w/deep palmar arch

Question 34

Describe radial a.'s path to the hand?

Answer 34

-Continues dorsally over lateral carpal bones, extends across the floor of the snuff box, and pierces the 1st dorsal interosseous m.

Question 35

What aa. come off from the radial a. in the hand?

Answer 35

- Princeps pollicis a. (medial thumb supply) - radialis incidis a. (lateral 2nd digit supply) - Continue to deep palmar arch, which will anastomose w/deep branch of ulnar a. - Superficial palmar branch (found at midpoint of metacarpal)

Question 36

What nerves do the median n. branch into in the hand?

Answer 36

Common palmar digital and proper palmar digital branches

Question 37

What nerves do the ulnar n. branch into in the hand?

Answer 37

- Palmar cutaneous branch (medial palm) - Dorsal cutaneous branch - Superficial branch (becomes common palmar digital nerves and then proper palmar digital nerves) (- Deep branch, not highlighted)

Question 38

What nerves do the radial n. branch into in the hand?

Answer 38

- Superficial branch | - Dorsal digital nerves

Question 39

What causes claw hand/ulnar claw? What are the sx?

Answer 39

- Ulnar n. palsy causes unopposed activity of the extensor digitorum m. - Intrinsic hand m. weakness; hyperextension of 4th and 5th metacarpophalangeal joints, flexion of DIPs and PIPs; loss of ability to spread fingers due to loss of interossei

Question 40

What causes ape hand? What are the sx?

Answer 40

- Median n. palsy leads to wasting of thenar mm. | - Inability to oppose thumb, thumb is pulled posteriorly and lines up w/other digits

Question 41

What causes Hand of Benediction/Pope's blessing? What are the sx?

Answer 41

- Median n. palsy leads to deformity only while trying to make fist - Inability to flex lateral 3.5 fingers

Question 42

What causes wrist drop?

Answer 42

-Radial n. palsy: loss of motor innervation to wrist extensors (usually dmg proximal to elbow joint)