Elbow, Cubital Fossa, & Forearm Flashcards
What is the proximal boundary of the cubital fossa?
The line that transverses between the epicondyles
What is the medial boundary of the cubital fossa?
The pronator teres
What is the lateral boundary of the cubital fossa?
The brachioradialis muscle
What is the distal boundary of the cubital fossa?
The junction between brachioradialis and pronator teres
What is the floor of the cubital fossa?
The brachialis muscle before it attaches to the ulnar tuberosity, and the supinator muscle as it arises from supinator crest of ulna before passing posterior to proximal radius
What is the roof of the cubital fossa?
The antebrachial fascia,
cephalic vein laterally and basilic vein medially
median cubital vein connects cephalic / basilic veins
medial and lateral cutaneous nerves of forearms
bicipital aponeurosis (continuous with antebrachial fascia medially)
What are the contents of the cubital fossa?
TAN - Tendon of biceps, brachial Artery, median Nerve. From lateral to medial
What are the posterior and anterior compartments of the forearm defined by?
Posterior - radial nerve or its branches
Anterior - median or ulnar nerves.
Radius and ulna connected by interosseus membrane
Posterior kinda wraps around the radius because of the continuation of the lateral intermuscular septum from the arm
Where do all of the superficial muscles of the anterior forearm originate from?
Common flexor tendon which attaches to medial epicondyle of humerus
Where does the median nerve exit the cubital fossa?
Passing between the two heads of the pronator teres (it has an ulnar and humeral head)
Where does the ulnar nerve enter the forearm?
Passing between the two heads of the flexor carpi ulnaris
What are the origin, insertion, innervation, and action of the pronator teres?
Origin: Humeral head from common flexor tendon, ulnar head from medial side of coronoid process
Insertion: Lateral surface of radius, mid-shaft
Innervation: Median nerve
Pronates arm, weakly flexes it via humeral head
What are the origin, insertion, innervation, and action of the flexor carpi radialis (FCR)?
Origin: Common flexor tendon
Insertion: base of metacarpals II and III (attaches towards radial side of carpi bones)
Innervation: Median nerve
Flexes and abducts hand at wrist
What are the origin, insertion, innervation, and action of the palmaris longus?
Origin: Common flexor tendon
Insertion: Palmar aponeurosis
Innervation: Median nerve
Flexes hand at wrist
What are the origin, insertion, innervation, and action of the flexor carpi ulnaris (FCU)?
Origin: Humeral head from common flexor tendon. Ulnar head from olecranon / posterior ulna
Insertion: Base of metacarpal V, hamate, and pisiform
Innervation: Ulnar nerve
Flexes and adducts hand at wrist
Where does the median nerve go after it passes through the two heads of the pronator teres?
It passes deep to the humero-ulnar head of flexor digitorum superficialis (FDS), along with ulnar artery
What is the intermediate muscle layer of the anterior compartment?
Just the FDS. Innervated by median nerve
What are the origin, insertion, innervation, and action of the flexor digitorum superficialis (FDS)?
Origin: Humero-ulnar head from medial epicondyle and adjacent margin of coronoid process, radial head from oblique line of radius
Insertion: Intermediate phalanges of digits II-V
Innervation: Median nerve
Action - Flexes intermediate phalanx, also causes flexion at metacarpophalangeal and wrist joints
What muscles are in the deep muscle layer of the anterior compartment?
Flexor Pollicis Longus (FPL), Flexor Digitorum Profundus (FDP), and Pronator Quadratus
What are the origin, insertion, innervation, and action of the flexor pollicis longus (FPL)?
Origin: Anterior surface of radius and radial half of interosseous membrane
Insertion: Base of distal phalanx of thumb
Innervation: Median nerve (anterior interosseous nerve)
Action: Flexes distal phalanx of thumb, can also cause flexion at metacarpophalangeal joint of thumb
What are the origin, insertion, innervation, and action of the flexor digitorum profundus (FDP)?
Origin: Anterior and medial surface of ulna, medial half of interosseous membrane (just medial to in FPL origin)
Insertion: Distal phalanx of digits II-V
Innervation: Lateral half by median nerve (anterior interosseous nerve) and medial half by ulnar nerve
Flexes distal phalanx of digits II-V, also causes flexion at metacarpophalangeal and wrist joint
What are the origin, insertion, innervation, and action of the pronator quadratus?
Origin: distal anterior surface of ulna
Insertion: distal anterior surface of radius
Innervation: Median nerve (anterior interosseous nerve)
Pronates the forearm