Elbow and Forearm Anatomy – Review Flashcards

Question-and-answer flashcards summarizing key bones, joints, ligaments, muscles, nerves, vessels, and clinical correlations of the elbow and forearm region. Use them to test anatomy knowledge and prepare for exams.

Which three bones form the elbow joint?

Humerus, Ulna, Radius

Name the three articulations that make up the elbow complex.

Humero-radial joint (HRJ), Humero-ulnar joint (HUJ), Proximal radioulnar joint (PRUJ)

What structure on the humerus articulates with the radial head?

Capitulum (capitellum)

Where is the ulnar nerve located at the elbow?

Posterior inferior surface of the medial epicondyle (ulnar groove)

What is the normal carrying angle of the elbow in adult males?

10–15° valgus

A carrying angle greater than 15° is more commonly seen in which sex?

Females

What type of joint is the humeroulnar joint usually classified as?

Hinge joint

The humeroradial joint is anatomically what type of joint?

Ball-and-socket joint

What type of joint is the proximal radioulnar joint?

Pivot joint

Which ligament holds the radial head against the ulna?

Annular ligament

Which ligament is the primary stabilizer against valgus stress at the elbow?

Ulnar (medial) collateral ligament (UCL)

Name the three bands of the UCL.

Anterior, Posterior, Transverse (oblique)

Reconstruction of which elbow ligament is commonly referred to as "Tommy John" surgery?

Ulnar (medial) collateral ligament

Which ligament resists varus stress at the elbow?

Radial (lateral) collateral ligament

Rupture of the lateral ulnar collateral ligament can lead to what instability pattern?

Posterolateral rotatory instability (PLRI)

Which three structures provide primary, secondary, and tertiary stability to the elbow?

Primary: humeroulnar joint architecture; Secondary: ligamentous support (especially medially); Tertiary: muscular support

What forms the roof of the cubital fossa?

Deep fascia reinforced by the bicipital aponeurosis, subcutaneous tissue, and skin

List the borders of the cubital fossa.

Superior: line between epicondyles; Medial: Pronator teres; Lateral: Brachioradialis; Floor: Brachialis

Name four superficial veins commonly found over the cubital fossa.

Cephalic, Basilic, Median cubital, (variable) median antebrachial

What five structures lie within the cubital fossa?

Terminal brachial artery, radial & ulnar artery origins, biceps brachii tendon, median nerve, medial & lateral antebrachial cutaneous nerves

How many muscles cross the elbow joint in total?

Seventeen

Which compartment of the forearm contains the flexors and pronators?

Anterior (volar) compartment

Which compartment of the forearm contains extensors and supinators?

Posterior (dorsal) compartment

Name the four muscles of the superficial anterior forearm group.

Pronator teres, Flexor carpi radialis, Palmaris longus, Flexor carpi ulnaris

What nerve innervates Pronator teres?

Median nerve

Which anterior superficial muscle is absent in about 10–20 % of people?

Palmaris longus

What is the only superficial anterior forearm muscle innervated by the ulnar nerve?

Flexor carpi ulnaris

Which muscle forms the intermediate layer of the anterior forearm?

Flexor digitorum superficialis

Flexor digitorum profundus has dual innervation; which nerves supply its medial and lateral halves?

Medial half: Ulnar nerve; Lateral half: Anterior interosseous nerve (from median)

Which deep anterior muscle flexes the distal phalanx of the thumb?

Flexor pollicis longus

What deep anterior muscle binds the radius and ulna together?

Pronator quadratus

All posterior compartment muscles are supplied by which nerve (or its branches)?

Radial nerve

Name the seven muscles of the superficial posterior forearm group.

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

Which posterior superficial muscle flexes the elbow when the forearm is in mid-pronation?

Brachioradialis

Which two muscles lie in the deep posterior forearm group?

Supinator, Extensor indicis

List the three muscles of the outcropping (thumb) group.

Abductor pollicis longus, Extensor pollicis brevis, Extensor pollicis longus

Around which bony landmark does the tendon of extensor pollicis longus wrap?

Dorsal (Lister’s) tubercle of the radius

How many extensor tunnels are at the wrist, and what holds the tendons in place?

Six tunnels; extensor retinaculum

Which muscles pass through extensor tunnel 1?

Extensor pollicis brevis and Abductor pollicis longus

Which muscles pass through extensor tunnel 2?

Extensor carpi radialis longus and brevis

Which nerve innervates all posterior arm and forearm muscles?

Radial nerve

The deep branch of the radial nerve becomes what nerve after passing the lower border of supinator?

Posterior (dorsal) interosseous nerve

What branch of the median nerve supplies the deep anterior forearm?

Anterior interosseous nerve

Name the artery that splits into radial and ulnar arteries in the cubital fossa.

Brachial artery

Which artery gives rise to the common interosseous artery?

Ulnar artery

The anterior interosseous artery eventually joins which arch on the dorsum of the hand?

Dorsal carpal arch

Which elbow ligament is weak because it attaches to the annular ligament rather than bone?

Radial (lateral) collateral ligament

What muscle inserts on the ulnar tuberosity?

Brachialis

Which muscle inserts on the radial tuberosity?

Biceps brachii

What structure separates the distal ulna from the carpal bones?

Triangular fibrocartilage complex (TFCC)

During pronation and supination, the distal radius moves around which bone?

Ulna

In which extensor tunnel does the extensor digitorum tendon travel?

Tunnel 4

Which nerve supplies sensation to the dorsal lateral hand up to the radial half of digit 3?

Superficial branch of the radial nerve

Which muscle supinates the forearm and is pierced by the deep branch of the radial nerve?

Supinator

List the muscles of the forearm that are innervated by the median nerve and what layer they are in

pronator teres (anterior superficial), flexor carpi radialis (anterior superficial), palmaris longus (anterior superficial), and flexor digitorum superficialis (anterior intermediate)

List the muscles of the forearm that are innervated by the anterior interosseous nerve (of median nerve) and what layer they are in.

flexor pollicis longus (anterior deep), flexor digitorum profundus (lateral half) (anterior deep), and pronator quadratus (anterior deep)

List the muscles of the forearm that are innervated by the radial nerve and what layer they are in.

brachioradialis (posterior superficial), ext. carpi radialis longus (posterior superficial), and anconeus (posterior superficial)

List the muscles of the forearm that are innervated by the deep branch of radial nerve and what layer they are in.

ext. carpi radialis brevis (posterior superficial) and supinator (posterior deep)

List the muscles of the forearm that are innervated by the posterior interosseous (of radial nerve) and what layer they are in.

ext. digitorum (posterior superficial), ext. digiti minimi (posterior superficial), ext. carpi ulnaris (posterior superficial), ext. indicis (posterior deep), ext. pollicis brevis (posterior outcropping), ext. pollicis longus (posterior outcropping), and abductor pollicis longus (posterior outcropping)