Anterior Compartment of the Arm, Forearm and Cubital Fossa

Question 1

What are the three muscles of the anterior compartment of the arm?

Answer 1

Biceps brachii, Coracobrachialis, Brachialis

Question 2

What are the muscles of the anterior compartment of the arm supplied by?

Answer 2

Musculocutaneous nerve

Question 3

Which muscle is most anteriorly positioned in the anterior compartment of the arm?

Answer 3

Biceps brachii

Question 4

Proximal and distal attachments of the biceps brachii muscle?

Answer 4

Proximal: Short head- tip of coracoid process of scapula, long head- supraglenoid tubercle of scapula
Distal: The biceps tendon, which attaches to the radial tuberosity and the bicipital aponeurosis, which blends with the deep (antebrachial) fascia on the medial side of the proximal forearm.

Question 5

Main actions of the anterior compartment of the arm?

Answer 5

Flexion of the arm and forearm

Question 6

Proximal and distal attachments of the coracobrachialis muscle?

Answer 6

Proximal: coracoid process of the scapula
Distal: humerus

Question 7

Proximal and distal attachments of the brachialis muscle?

Answer 7

Proximal: Humerus
Distal: Coronoid process of the ulna

Question 8

What three muscles attach to the corocoid process of the scapula?

Answer 8

pectoralis minor, coracobrachialis & short head of biceps.

Question 9

Coracobrachialis is deep to ___1____and medial to ____2______. Coracobrachialis is separated from the triceps by the _______3________.

Answer 9

1) biceps brachii
2) brachialis
3) medial intermuscular septae

Question 10

Describe innervation of the anterior muscles of the forearm

Answer 10

The muscles of this compartment are all supplied by the median nerve except for the flexor carpi ulnaris and the medial part (to digits 4 & 5) of flexor digitorum profundus, which are supplied by the ulnar nerve.

Question 11

What are the muscles of the anterior compartment of the forearm superficial layer?

Answer 11

Pronator teres, flexor carpi ulnaris, flexor carpi radialis, palmaris longus

Question 12

What are the muscles of the anterior compartment of the forearm intermediate layer?

Answer 12

Flexor digitorium superficialis

Question 13

What are the muscles of the anterior compartment of the forearm deep layer?

Answer 13

Flexor pollicis longus, flexor digitorium profundus, pronator quadratus

Question 14

Where do all the anterior forearm superficial muscles proximally attach to?

Answer 14

common flexor tendon to the medial condyle of the humerus

Question 15

Distal attachments of the palmaris longus, flexor carpi radials, flexor carpi ulnaris?

Answer 15

Palmaris longus: attaches distally to the palmar aponeurosis.
Flexor carpi radialis: attaches distally to the metacarpals on the radial side.
Flexor carpi ulnaris: attaches distally to the metacarpals on the ulnar side.

Question 16

Attachments of intermediate anterior forearm layer?

Answer 16

muscles attach proximally to medial epicondyle of humerus, coronoid process of ulna and radial head:
- Flexor digitorum superficialis: Four muscle bellies/tendons for the medial four digits.

Question 17

Attachments of the deep anterior forearm layer?

Answer 17

muscles attach proximally to the anterior surfaces of the radius or ulna:

• Flexor digitorum profundus: attaches distally to digits 2-5.
• Flexor pollicis longus: attaches distally to thumb
• Pronator quadratus: attaches between distal anterior surfaces of radius and ulna.

Question 18

The muscle bellies of anterior forearm are only found within the compartment whereas their long tendons pass to the ______1_____, held in place by the _______2_________ at the wrist joint/carpus respectively.

Answer 18

1) wrist and hand

2) palmar carpal ligament and flexor retinaculum

Question 19

The common flexor origin is a common tendon, which attaches proximally to the _______1_______. Pain felt in the area of the medial epicondyle can be a result of ____________2___________________

Answer 19

1) medial epicondyle of the humerus
2) tendonitis of this common flexor tendon, a condition referred to by patients as “golfers elbow” (medial epicondylitis)

Question 20

Describe the boundaries of the cubital fossa?

Answer 20

Superior boundary: A transverse line between the epicondyles of the humerus.
Medial boundary: Pronator teres
Lateral boundary: brachioradialis

Question 21

Where does the brachial artery bifurcate?

Answer 21

at the apex of the cubital fossa triangle (bottom)

Question 22

Where does the radial nerve divide into superficial and deep branches?

Answer 22

deep to the brachialis

Question 23

The ulnar nerve crosses the_______1_________ where it can be palpated and readily injured (“funny bone” site). It passes through_____2_______ to reach the anterior compartment of forearm.

Answer 23

1) posterior surface of the medial epicondyle of the humerus

2) flexor carpi ulnaris (in the cubital tunnel)

Question 24

Actions of the anterior compartment of the forearm?

Answer 24

Flexion of the wrist and digits, pronation, abduction and adduction of the wrist.

Question 25

Contents of the cubital fossa?

Answer 25

TAN

biceps tendon, brachial artery, median nerve