Netter’s Anatomy Flash Cards: Upper Limb

A collection of vocabulary flashcards covering the anatomy, joints, muscles, nerves, and clinical conditions of the human upper limb based on Netter's Anatomy Flash Cards.

Scapula

Also known as the shoulder blade, it articulates with the clavicle and the head of the humerus, with $17$ different muscles attaching to it.

Surgical neck of the humerus

A region just below the lesser tubercle that is a common fracture site; such fractures may injure the axillary nerve.

Glenohumeral joint

A multiaxial synovial ball-and-socket (spheroidal) joint between the glenoid cavity of the scapula and the head of the humerus.

Acromioclavicular joint

A synovial plane joint between the acromion and clavicle that permits gliding movement as the arm is raised.

Glenoid labrum

A fibrocartilaginous lip that serves to deepen the glenoid cavity.

Olecranon

The point of the elbow, located posteriorly and proximally on the ulna, which fits into the olecranon fossa of the humerus during full extension.

Colles’ fracture

A fracture of the distal radius typically resulting from a fall on an outstretched hand, often resulting in a "dinner fork" deformity.

Scaphoid

The most commonly fractured carpal bone, located just below the "anatomic snuffbox."

Thumb (1st digit) phalanges

Unlike digits $2$ through $5$ which have three, this digit has only two phalanges: proximal and distal.

Trapezius

A large muscle innervated by the spinal accessory nerve ($CN XI$) that acts to rotate, elevate, retract, and depress the scapula.

Latissimus dorsi

A muscle that extends, adducts, and medially rotates the humerus, innervated by the thoracodorsal nerve ($C6-C8$).

Levator scapulae

A muscle arising from the first $4$ cervical vertebrae that elevates the superior angle of the scapula and tilts the glenoid cavity inferiorly.

Deltoid

A thick, triangular muscle that covers the shoulder joint and is the principal abductor of the arm; it is innervated by the axillary nerve ($C5$ and $C6$).

Rotator cuff muscles

A group of four muscles—Supraspinatus, Infraspinatus, Teres minor, and Subscapularis—that reinforce and stabilize the shoulder joint.

Supraspinatus tendon

The most vulnerable component of the rotator cuff to injury from repeated abduction and flexion.

Scapulothoracic joint

A functional articulation between the subscapularis and serratus anterior muscles that permits gliding of the scapula on the chest wall.

Pectoralis major

A fan-shaped muscle that adducts and medially rotates the humerus; its sternocostal portion is tested by adducting the arm against resistance.

Biceps brachii

A fusiform muscle that acts as a powerful supinator of the forearm and a flexor of the elbow, innervated by the musculocutaneous nerve ($C5$ and $C6$).

Brachialis

The most powerful flexor of the forearm at the elbow, located deep to the biceps brachii.

Triceps brachii

The chief extensor of the forearm at the elbow, consisting of long, lateral, and medial heads innervated by the radial nerve ($C7$ and $C8$).

Pronator teres

A muscle of the anterior forearm suited for quick, powerful pronation, innervated by the median nerve ($C6$ and $C7$).

Palmaris longus

A vestigial muscle in humans that is absent in $10-15\%$ of the population.

Cubital tunnel syndrome

Compression of the ulnar nerve as it passes between the two heads of the flexor carpi ulnaris, which may worsen during elbow flexion.

Supinator

A muscle that rotates the radius to supinate the hand and can function regardless of whether the elbow is flexed or extended.

Brachioradialis

A unique posterior compartment muscle innervated by the radial nerve that acts as a weak elbow flexor rather than an extensor.

Anatomic snuffbox

A dorsal region at the base of the thumb bounded medially by the extensor pollicis longus tendon and laterally by the abductor pollicis longus and extensor pollicis brevis tendons.

Thenar muscles

The group of three muscles at the base of the thumb (Abductor pollicis brevis, Flexor pollicis brevis, Opponens pollicis) all innervated by the recurrent branch of the median nerve ($C8$ and $T1$).

Lumbrical muscles

Four small muscles that flex the metacarpophalangeal joints and extend the interphalangeal joints.

Dorsal interosseous muscles

Bipennate muscles that abduct the fingers from the midline (middle finger).

Palmar interosseous muscles

Unipennate muscles that adduct the fingers toward the midline (middle finger).

Brachial Plexus

A network formed by the ventral rami of $C5-T1$ spinal nerves that supplies the muscles and skin of the upper extremity.

Erb’s palsy

An upper plexus injury ($C5-C6$) affecting the shoulder and arm, characterized by an extended elbow and flexed wrist.

Klumpke’s palsy

A lower plexus injury ($C7-T1$) resulting in a weak grasp due to the loss of forearm and hand muscle flexion.

Saturday night palsy

Compression of the radial nerve leading to weakened elbow, wrist, and finger extension, commonly presenting as wristdrop.

Median cubital vein

A superficial vein that joins the cephalic and basilic veins in the cubital fossa; it is the most common site for venipuncture.

Allen’s test

A clinical procedure used to assess vascular perfusion to the hand by testing the patency of the radial and ulnar arteries through the palmar arches.