Medial boundary of cubital fossa:
Pronator teres m.
Proximal boundary of cubital fossa:
Line between the epicondyles
Lateral boundary of cubital fossa:
Brachioradialis m.
Distal boundary of cubital fossa:
Junction of brachioradialis and pronator teres mm
Posterior boundary (floor) of cubital fossa:
Brachialis m - before it inserts on ulnar tuberosity
Supinator m - as it arises from supinator crest of ulna before passing posterior to proximal radius
Anterior boundary (roof) of cubital fossa:
Antebrachial fascia - continuous with brachial fascia
Cephalic v (lateral), basilic v (medial), median cubital v (connecting)
Medial cutaneous n. of forearm (separate branch of medial cord), lateral cutaneous n. of forearm (termination of musculocutaneous)
Bicipital aponeurosis - medial extension f biceps tendon which fuses with forearm fascia
Contents of cubita fossa:
TENDON of biceps brachii m.
ARTERY - Brachial a. - bifurcates into radial and ulnar aa here
NERVE - Median n. - enters fossa anterior to brachialis m.
(from lateral to medial)
Superficial muscle layers of the forearm:
All arise from common flexor tendon (attaches to medial epicondyle), all innervated by median n. except for flexor carpi ulnaris longus (ulnar n.)
- Pronator teres
- Flexor carpi radialis (FCR)
- Palmaris longus
- Flexor carpi ulnaris (FCU)
Median n. exits the cubital fossa by passing between two heads of ________.
Pronator teres
Ulnar n. enters the forearm by passing between two heads of ________.
Flexor carpi ulnaris
Pronator teres:
O: Humeral head - common flexor tendon, Ulnar head - medial side of coronoid process
I: Lateral surface of mid-shaft of radius
N: Median n.
A: Pronation of forearm
Flexor carpi radialis (FCR):
O: Common flexor tendon
I: Base of metacarpals 2 and 3
N: Median n.
A: Flexes and abducts hand at wrist
Palmaris longus:
O: Common flexor tendon
I: palmar aponeurosis
N: Median n.
A: flexes hand at wrist
Flexor carpi ulnaris (FCU):
O: Humeral head - common flexor tendon, Ulnar head - Olecranon and posterior ulna
I: Pisiform, hamate, and base of metacarpal 5
N: Ulnar n.
A: Flexes and adducts hand at wrist
Intermediate muscle layer:
Flexor digitorum superficialis
Flexor digitorum superficialis (FDS):
O: Ulnar-humeral head - from medial epicondyle and adjacent margin of coronoid process, Radial head - oblique line of radius
I: Intermediate phalanges of digits 2-5
N: Median n.
A: Flexes intermediate phalanx, flexion at metacarpophalangeal joints and wrist joint
Deep muscle layer of forearm:
Flexor pollicis longus, flexor digitorum profundus, pronator quadratus
Medial half of FDP innervated by ulnar n; median n. runs between FDS and FDP; ulnar a. and n. run between FDP and flexor carpi ulnaris
Flexor pollicis longus (FPL):
O:Anterior surface of radius and radial half of interrosseous membrane
I: Base of distal phalanx of thumb
N: Median n. (anterior interosseous n)
A: Flexes distal phalanx of thumb
Flexor digitorum profundus (FDP):
O: Anterior and medial surface of ulna and medial half of interosseous membrane
I: Distal phalanx of digits 2-5
N: Lateral half - median n (anterior interosseous) Medial half - ulnar n.
A: Flexes distal phalanx of digits 2-5
Pronator quadratus:
O: Distal anterior surface of ulna
I: Distal anterior surface of radius
N: Median n. (anterior interosseous n)
A: Pronation of forearm
The brachial a. divides into the ______ and the ______ in the cubital fossa.
Radial a. and ulnar a.
The radial a. relates to the deep surface of the _________ m. and superficial radial n.
Brachioradialis m.
The ulnar n. gives off the _______ which in turn divides into an ______ and ________ interosseous aa.
Common interosseous a; anterior; posterior
The ulnar a. accompanies the ________ between the two heads of the ____________.
Median n; Flexor digitorum superficialis
The radial n. divides into superficial and deep branches adjacent to the _________.
Cubital fossa
The deep radial n. enters the ________.
Supinator m
The median n. gives off the _______ near the apex of the cubital fossa before exiting between the 2 heads of the pronator teres.
Anterior interosseous n.
Posterior compartment - Superficial muscle layer
Extension of the hand at the wrist joint, extension of digits, supination of forearm. Arise from the common extensor tendon which attaches on the lateral epicondyle or the lateral supracondylar ridge. The radial a. and the superficial radial n. lie just deep to the brachioradialis
Brachioradialis:
O: Lateral supracondylar ridge
I: Lateral distal radius
N: Radial n.
A: FLEXOR of the forearm
Anconeus:
O: Lateral epicondyle
I: Olecranon and posterior surface of ulna
N: Radial n.
A: Accessory extension of the forearm, also pulls the ulna out of the during pronation
Extensor carpi radialis longus:
O: Right next to the brachioradialis, lateral supracondylar ridge
I: Base of metacarpal II
N: Radial n.
A: Extends and abducts the hand at wrist joint
Extensor carpi radialis brevis:
O:Common extensor tendon
I: Base of metacarpals II and III
N: Deep radial n.
A: Extends and abducts the hand at the wrist joint
Extensor carpi ulnaris:
O: Common extensor tendon and posterior border of ulna
I: Base of metacarpal V
N: Radial n - Posterior interosseous n.
A: Extends and adducts the hand at the wrist
Extensor digitorum:
O: Common extensor tendon
I: Extensor hoods of digits II-V
N: Radial n - Posterior interosseous n.
A: Extends digits II-V
Extensor digiti minimi:
O: Common extensor tendon
I: Extensor hood of digit V
N: Radial n - Posterior interosseous n.
A: Extends digit V
Deep muscle layers of the posterior forearm:
All are innervated by the deep radial or posterior interosseous nn. Supinator, extensor indicis, extensor pollicis longus, extensor pollicis brevis, and abductor pollicis brevis
The deep radial n. passes between the two heads of the ______ and emerges from the muscle as the __________.
Supinator; Posterior interosseous n.
Supinator:
O: Superficial part - lateral epicondyle, Deep part - supinator crest of ulna
I: Lateral proximal radius
N: Deep radial n.
A: Supination of forearm
Extensor indicis:
O: Posterior surface of ulna distal to extensor pollicis longus and adjacent interosseous membrane
I: Dorsal hood of digit II
N: Posterior interosseous n. (Radial)
A: Extends digit II
Extensor pollicis longus:
O: Posterior ulna distal to the abductor pollicis longus
I: Distal phalanx of thumb
N: Posterior interosseous n (Radial)
A: Extens distal phalanx of thumb, can also extend carpometacarpal and metacarpophalangeal joints of thumb
Extensor pollicis brevis:
O: Posterior surface of radius distal to abductor pollicis longus and adjacent interosseous membrane
I: Proximal phalanx of thumb
N: Posterior interosseous n (Radial)
A: Extends proximal thumb phalanx
Abductor pollicis longus:
O: Posterior proximal surfaces of the ulna and radius and adjacent interosseous membrane
I: Lateral base of metacarpal I
N: Posterior interosseous n (Radial)
A: Abducts thumb at carpmetacarpal joint
The main blood supply to the posterior forearm is from the _________, accompanied by the ___________, a branch of the radial n.
Posterior interosseous a. from the common interosseous a; posterior interosseous n.
The ______ passes between the two heads of the supinator.
Deep branch of radial n.
When it emerges from the _______ m, the radial n. changes its name to the _________.
Supinator; Posterior interosseous n.
Medial cutaneous n. of forearm comes from?
Medial cord
Lateral cutaneous n. of forearm comes from?
Terminal branch of musculocutaneous n.
Posterior cutaneous n. of the forearm comes from?
Branch of radial n. originating above the elbow
Ligaments of the elbow joint include:
- Radial collateral ligament - lateral epicondyle to annular ligament
- Ulnar collateral ligament - medial epicondyle to medial edge of trochlear notch
- Annular ligament surrounds the neck of the radius
Radioulnar joints - Proximal:
Radius articulates with radial notch of ulnar
Radioulnar joints - Distal:
Head of ulnar articulates with ulnar notch of radius