Anterior Compartment of the Arm, Forearm and Cubital Fossa Flashcards
What are the three muscles of the anterior compartment of the arm?
Biceps brachii, Coracobrachialis, Brachialis
What are the muscles of the anterior compartment of the arm supplied by?
Musculocutaneous nerve
Which muscle is most anteriorly positioned in the anterior compartment of the arm?
Biceps brachii
Proximal and distal attachments of the biceps brachii muscle?
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.
Main actions of the anterior compartment of the arm?
Flexion of the arm and forearm
Proximal and distal attachments of the coracobrachialis muscle?
Proximal: coracoid process of the scapula
Distal: humerus
Proximal and distal attachments of the brachialis muscle?
Proximal: Humerus
Distal: Coronoid process of the ulna
What three muscles attach to the corocoid process of the scapula?
pectoralis minor, coracobrachialis & short head of biceps.
Coracobrachialis is deep to ___1____and medial to ____2______. Coracobrachialis is separated from the triceps by the _______3________.
1) biceps brachii
2) brachialis
3) medial intermuscular septae
Describe innervation of the anterior muscles of the forearm
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.
What are the muscles of the anterior compartment of the forearm superficial layer?
Pronator teres, flexor carpi ulnaris, flexor carpi radialis, palmaris longus
What are the muscles of the anterior compartment of the forearm intermediate layer?
Flexor digitorium superficialis
What are the muscles of the anterior compartment of the forearm deep layer?
Flexor pollicis longus, flexor digitorium profundus, pronator quadratus
Where do all the anterior forearm superficial muscles proximally attach to?
common flexor tendon to the medial condyle of the humerus
Distal attachments of the palmaris longus, flexor carpi radials, flexor carpi ulnaris?
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.
Attachments of intermediate anterior forearm layer?
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.
Attachments of the deep anterior forearm layer?
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.
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.
1) wrist and hand
2) palmar carpal ligament and flexor retinaculum
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___________________
1) medial epicondyle of the humerus
2) tendonitis of this common flexor tendon, a condition referred to by patients as “golfers elbow” (medial epicondylitis)
Describe the boundaries of the cubital fossa?
Superior boundary: A transverse line between the epicondyles of the humerus.
Medial boundary: Pronator teres
Lateral boundary: brachioradialis
Where does the brachial artery bifurcate?
at the apex of the cubital fossa triangle (bottom)
Where does the radial nerve divide into superficial and deep branches?
deep to the brachialis
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.
1) posterior surface of the medial epicondyle of the humerus
2) flexor carpi ulnaris (in the cubital tunnel)
Actions of the anterior compartment of the forearm?
Flexion of the wrist and digits, pronation, abduction and adduction of the wrist.
