Lecture 13 - Arm, Elbow, and Forearm

Question 1

Biceps brachii

Innervation and action

Answer 1

Nerve: Musculoucutaneous nerve (C5, C6)
Action: Supinates forearm, and when supine flexes forearm. Short head resists dislocation of shoulder

Question 2

Brachialis

Innervation and action

Answer 2

Nerve: Musculoucutaneous nerve (C5, C6)
Action: Flexes forearm in all positions

Question 3

Coracobrachialis

Innervation and action

Answer 3

Nerve: Musculoucutaneous nerve (C5, C6, C7)
Action: Helps flex and adduct arm, resists dislocation of the shoulder

Question 4

Rupture results in “Popeye Deformity” of what tendon?

Answer 4

Long head of biceps tendon

Question 5

Triceps brachii

Innervation and action

Answer 5

Nerve: Radial Nerve (C6, C7, C8)
Action: Chief extensor of forearm, long head resists dislocation of humerus, important during abduction

Question 6

Anconeus

Innervation and action

Answer 6

Nerve: Radial Nerve (C7, C8, T1)
Action: Assists triceps in extending forearm, stabilizes elbow joint, may abduct ulna during pronation

Question 7

Important nerve/artery through Triangular space

Answer 7

-Circumflex scapular artery

Question 8

Important nerve/artery through Quadrangular space

Answer 8

• Post. Circumflex humeral artery

- Axillary nerve

Question 9

Important nerve/artery through Triangular interval

Answer 9

• Radial Nerve

- Deep artery of the arm

Question 10

Veins used for blood draw

Answer 10

Median cubital or basilic

Question 11

Cubital fossa borders

Answer 11

Line connecting the humeral epicondyles
Medially by the pronator teres
Laterally by the brachioradialis

Question 12

Superficial group of anterior forearm

Answer 12

Pronator teres
flexor carpi radialis
palmaris longus
flexor carpi ulnaris

Question 13

Intermediate group of anterior forearm

Answer 13

Flexor digitorum superficialis

Question 14

Deep group of anterior forearm

Answer 14

Flexor pollicis longus
flexor digitorum profundus
pronator quadratus

Question 15

Superficial group of anterior forearm innervation

Answer 15

All median nerve except

Flexor carpi ulnaris - Ulnar nerve

Question 16

Pronator teres action

Answer 16

Pronates forearm

Question 17

Flexor carpi radialis action

Answer 17

Flexes and abducts wrist

Question 18

Palmaris longus action

Answer 18

Flexes wrist

Question 19

Flexor carpi ulnaris action

Answer 19

Flexes and adducts wrist

Question 20

Flexor digitorum superficialis action

Answer 20

flexes PIP joints of digits 2-5

Question 21

Flexor pollicis longus action and innervation

Answer 21

Action: flexes IP joint of thumb
Innervation: anterior interosseous nerve

Question 22

Flexor digitorum profundus action and innervation

Answer 22

Action: flexes DIP joints of digits 2-5, can assist with wrist flexion

Innervation:
Laterally: Median nerve (anterior interosseous)
Medially: ulnar nerve

Question 23

Pronator quadratus action and innervation

Answer 23

Action: pronates forearm
Innervation: anterior interosseous nerve

Question 24

Superficial group of posterior forearm

Answer 24

Brachioradialis
Extensor carpi radialis longus
Extensor carpi radialis brevis
Extensor digitorum
Extensor digiti minimi
Extensor carpi ulnaris

Question 25

Deep group of posterior forearm

Answer 25

``` Supinator Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Extensor indicis ```

Question 26

Brachioradialis action

Answer 26

Unusual in that it flexes forearm

Question 27

Extensor Carpi Radialis Longus & Brevis action

Answer 27

Extend and abduct hand at wrist

Question 28

Extensor digitorum action

Answer 28

Tendons reach digits 2-5 Intertendinous connections form extensor expansions extensor expansions: Contribute to coordinated movements of the interphalangeal joints

Question 29

Extensor digiti minimi action

Answer 29

Typically divides into two tendons with the lateral one joined by the tendon of extensor digitorum to the little finger Provides independent extension of the little finger or acts with extensor digitorum

Question 30

Extensor carpi ulnaris action | extends and adducts the hand at the wrist joint

Answer 30

extends and adducts the hand at the wrist joint

Question 31

Supinator action

Answer 31

Supination

Question 32

Abductor pollicis longus action

Answer 32

Abducts and extends the first CM joint

Question 33

Extensor pollicis brevis action

Answer 33

Extends the MP joint and helps extend the CM joint

Question 34

Extensor pollicis longus action

Answer 34

Tendon passes medial to the dorsal tubercle of the radius, using it as a pulley Inserts into the distal phalanx of the thumb Extends the IP, MP, and CM joints of the thumb Forms the posterior boundary of anatomical snuff box

Question 35

Extensor indicis action

Answer 35

may act with extensor digitorum or may independently extend the index finger