Exam 3 - The Extensor Forearm and Hand

Question 1

What two muscles are innervated by deep branch of radial nerve?

Answer 1

Extensor carpi radialis brevis and supinator

Note: All extensors innervated by radial nerve

Question 2

The long flexor tendons to the medial four digits pass through the tunnel accompanied by what nerve?

Answer 2

The median nerve

Question 3

Tennis elbow occurs after heavy exertion involving forceful supination and pronation of the forearm. What tendon is inflamed in this condition?

Answer 3

Common extensor tendon

Question 4

What is the function and innervation of the brachioradialis muscle?

Answer 4

The brachioradialis flexes the forearm and is innervation by the radial nerve.

Question 5

A child sustains a fracture of the humerus just above the condyles. She cannot extend the metacarpophalangeal joints of her fingers or oppose her thumb to the other fingers. What nerve(s) may she have injured?

Answer 5

Radial and median nerves

Question 6

Inability to supinate the forearm means what nerve is affected?

Answer 6

Deep branch of radial nerve

Question 7

A patient can no longer adduct the thumb or abduct the little finger. What nerve is involved?

Answer 7

The deep branch of the ulnar nerve

Question 8

What nerve is responsible for extension of the interphalangeal joints via the lumbrical muscles?

Answer 8

1st and 2nd lumbricals: median nerve.

3rd and 4th lumbricals: ulnar nerve.

Question 9

The brachioradialis muscle is the only flexor innervated by what nerve?

Answer 9

Radial nerve

Question 10

The radial nerve descends on the arm between what two muscles?

Answer 10

Brachialis and brachioradialis

Question 11

“Tennis elbow” or the pain on the lateral aspect of the elbow, radiates down the lateral forearm and dorsal hand. This is caused by inflammation of what?

Answer 11

The Common Extensor tendon

Note: “Golfer’s elbow” is a similar pain caused by inflammation of the common flexor tendon

Question 12

The carpal groove is converted into the carpal tunnel by what structure?

Answer 12

Flexor retinaculum

Question 13

Which muscle has tendons found in two tiers within the carpal tunnel?

Answer 13

Flexor digitorum superficialis (3, 4 superficial; 2, 5 deep)

Question 14

Which muscles in the hand are innervated by the medial nerve?

Answer 14

All thenars (flexor pollicis brevis muscle, abductor pollicis brevis muscle, opponens pollicus muscle) and the 1st and 2nd lumbrical muscles

Question 15

Which muscles adduct the fingers?

Answer 15

Palmar interosseous muscles

Question 16

Which muscles abduct the fingers?

Answer 16

Dorsal interosseous muscles

Question 17

The ulnar artery supplies branches to all sides of the fingers except what two exceptions?

Answer 17

a. Thumb

b. Radial side of index finger

Question 18

The main trunk of the ulnar artery continues as the ______ palmar arch.

Answer 18

Superficial

Question 19

The main trunk of the radial artery continues as the ______ palmar arch.

Answer 19

Deep

Question 20

What enters the hand lateral to the ulnar nerve and superficial to the flexor retinaculum?

Answer 20

Ulnar artery

Question 21

What artery passes through the anatomical snuff box?

Answer 21

Radial artery

Question 22

What nerve is largely responsible for cutaneous supply of the palm?

Answer 22

Median nerve

Question 23

What is the floor of the cubital fossa? (2 muscles)

Answer 23

Brachialis

Supinator

Question 24

Cell bodies of skeletal motor (GSE) fibers are found where?

Answer 24

Anterior horn of spinal cord

Question 25

Cell bodies of sensory (GSA) fibers are found where?

Answer 25

Dorsal root ganglia

Question 26

Cell bodies of sympathetic preganglionic fibers are found where?

Answer 26

Lateral horn of spinal cord

Question 27

What three muscles does the Anterior Interosseous nerve supply?

Answer 27

Flexor pollicis longus
Pronator quadratus
1/2 of flexor digitorum profundus

Question 28

What muscle flexes the distal interphalangeal joints of the index and middle fingers?

Answer 28

Flexor digitorum profundus, which is innervated by median nerve for these fingers.
*Note: This muscle also supplies sensation distally to the second digit.

Question 29

What two lumbricals does the ulnar nerve innervate?

Answer 29

Medial two lumbricals

Question 30

If a patient cannot hold a piece of typing paper, what nerve is in danger?

Answer 30

Ulnar nerve: innervates palmar and dorsal interosseous muscles which are required for the abduction and adduction in holding typing paper