Upper Limb
Pectoral girdle, axilla and brachial plexus, arm, forearm, and hand.
32 entriesPectoral & scapular region: 10Axilla: 4Arm: 6Elbow & cubital fossa: 2Forearm: 7Wrist & hand: 3
Bones (6)
- Clavicle HYS-shaped strut connecting the upper limb to the axial skeleton; one of the most commonly fractured bones, usually in its middle third.
- Humerus HYLong bone of the arm. It articulates with the scapula at the shoulder and with the radius and ulna at the elbow, and four major nerves lie against it at predictable fracture sites.
- Radius HYLateral bone of the forearm. It rotates around the ulna in pronation and supination, and its distal end is one of the most commonly fractured sites in the body.
- Scaphoid HYBoat-shaped bone of the proximal carpal row. It is the most commonly fractured carpal bone and its proximal pole is prone to avascular necrosis.
- Scapula HYTriangular flat bone on the posterolateral thorax that gives attachment to the rotator cuff and forms the glenoid cavity of the shoulder joint.
- Ulna Medial, stabilizing bone of the forearm. Its trochlear notch forms the hinge of the elbow with the humerus.
Muscles (9)
- Biceps brachii HYTwo-headed muscle of the anterior arm and the most powerful supinator of the forearm; it also flexes the elbow.
- Deltoid HYTriangular muscle that forms the rounded contour of the shoulder. It is the main abductor of the arm beyond the first ~15° and is supplied by the axillary nerve.
- Infraspinatus HYRotator cuff muscle in the infraspinous fossa and the main lateral (external) rotator of the arm.
- Pronator teres Superficial muscle of the anterior forearm. It pronates the forearm, forms the medial border of the cubital fossa, and the median nerve passes between its two heads.
- Serratus anterior HYSerrated muscle on the lateral thoracic wall that protracts the scapula, rotates it upward, and holds it against the chest wall.
- Subscapularis HYLarge rotator cuff muscle on the costal surface of the scapula. It is the main medial rotator of the arm and the only cuff muscle inserting on the lesser tubercle.
- Supraspinatus HYRotator cuff muscle in the supraspinous fossa that initiates abduction and is the most commonly torn cuff tendon.
- Teres minor Small rotator cuff muscle from the lateral border of the scapula. It laterally rotates the arm and is supplied by the axillary nerve.
- Triceps brachii Three-headed muscle of the posterior arm and the chief extensor of the elbow; supplied by the radial nerve.
Nerves (7)
- Axillary nerve HYBranch of the posterior cord that passes through the quadrangular space around the surgical neck of the humerus to supply deltoid and teres minor.
- Brachial plexus HYNetwork formed by the ventral rami of C5–T1 that supplies the motor and most of the sensory innervation of the upper limb.
- Long thoracic nerve HYBranch arising directly from the C5–C7 roots that supplies serratus anterior; injury causes medial winging of the scapula.
- Median nerve HYFormed by roots from the lateral and medial cords. It supplies most of the anterior forearm and the thenar muscles, and passes through the carpal tunnel.
- Musculocutaneous nerve Lateral cord branch that pierces coracobrachialis, supplies the anterior arm muscles, and ends as the lateral cutaneous nerve of the forearm.
- Radial nerve HYLargest branch of the brachial plexus (posterior cord). It supplies all extensor muscles of the arm and forearm and winds around the humerus in the radial groove.
- Ulnar nerve HYMedial cord branch that passes behind the medial epicondyle and through Guyon's canal. It supplies most intrinsic hand muscles and the medial 1½ digits.
Arteries (4)
- Axillary artery HYContinuation of the subclavian artery through the axilla, divided into three parts by pectoralis minor, with six named branches.
- Brachial artery HYMain artery of the arm, continuing from the axillary artery. It gives the profunda brachii, then divides in the cubital fossa into the radial and ulnar arteries; it's the site for blood pressure measurement.
- Radial artery HYSmaller terminal branch of the brachial artery. It is palpated at the wrist, used for ABGs, arterial lines and cardiac catheterization, and forms most of the deep palmar arch.
- Ulnar artery Larger terminal branch of the brachial artery. It gives the common interosseous artery, enters the hand through Guyon's canal, and forms most of the superficial palmar arch.
Joints (3)
- Elbow joint HYHinge joint between the humerus, ulna and radius. It shares a capsule with the proximal radioulnar joint and is the site of common overuse and pediatric injuries.
- Glenohumeral joint HYBall-and-socket joint between the humeral head and the glenoid cavity. It is the most mobile joint in the body and the most frequently dislocated major joint.
- Wrist joint HYCondyloid joint between the distal radius (and articular disc) and the proximal carpal row. It's a common site of fractures, instability and tenosynovitis.
Spaces & regions (3)
- Axilla HYPyramidal space between the arm and the thoracic wall. It is the passageway for the neurovascular bundle of the upper limb and contains the axillary lymph nodes, which drain most of the breast.
- Carpal tunnel HYOsseofibrous tunnel on the palmar wrist, formed by the carpal bones and the flexor retinaculum, that carries the median nerve and nine long flexor tendons.
- Cubital fossa HYTriangular depression on the anterior elbow containing the biceps tendon, brachial artery and median nerve. It is the usual site for venipuncture and blood pressure auscultation.