Humerus Anatomy Quiz: Shoulder Joint Structure Flashcards

Study Notes

The Upper End of Humerus

The anatomic neck separates the articular surface of the humerus
The surgical neck is a common site of fracture in the elderly, and contains the axillary nerve and circumflex humeral vessels
The greater and lesser tuberosities are separated by the bicipital groove, which contains the long head of biceps
Fractures of the humeral surgical neck are common in elderly people
Greater tuberosity fractures are more common than lesser tuberosity fractures

The Joints of the Shoulder Region

The shoulder joint articulates with the glenoid cavity
The sternoclavicular joint articulates between the sternal end of the clavicle, the 1st costal cartilage, and the manubrium
The sternoclavicular joint has a small range of motion, with forward movement facilitated by the serratus anterior muscle
The acromioclavicular joint and shoulder joint are also part of the shoulder region

Branches of the Radial Artery

The radial artery has muscular branches to neighboring muscles
The recurrent branch takes part in the arterial anastomosis around the elbow joint
The superficial palmar branch joins the ulnar artery to form the superficial palmar arch

Nerves of the Anterior Fascial Compartment of the Forearm

The median nerve passes between the two heads of the pronator and continues downward behind the flexor digitorum superficialis
The median nerve rests posteriorly on the flexor digitorum profundus and enters the palm by passing behind the flexor retinaculum

Branches of the Median Nerve in the Forearm

The median nerve has muscular branches to the pronator teres, flexor carpi radialis, palmaris longus, and flexor digitorum superficialis
The median nerve has articular branches to the elbow joint and an anterior interosseous nerve
The palmar cutaneous branch is distributed to the skin over the lateral part of the palm

Anterior Interosseous Nerve

The anterior interosseous nerve arises from the median nerve as it emerges from between the two heads of the pronator teres
The anterior interosseous nerve passes downward on the anterior surface of the interosseous membrane and ends on the anterior surface of the carpus

Muscles of the Posterior Fascial Compartment of the Forearm

The deep group includes the supinator, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, and extensor indicis

Contents of the Posterior Fascial Compartment of the Forearm

The compartment is supplied by the posterior and anterior interosseous arteries
The deep branch of the radial nerve provides nerve supply to the muscles

The Anterior and Posterior Interosseous Arteries

The anterior and posterior interosseous arteries arise from the common interosseous artery, a branch of the ulnar artery
They pass downward on the anterior and posterior surfaces of the interosseous membrane, respectively, and supply the adjoining muscles and bones

The Movement of Supination

Pronation is performed by the pronator teres and the pronator quadratus
Supination is performed by the biceps brachii and the supinator
Supination is the more powerful of the two movements due to the strength of the biceps muscle

Bones of the Hand

There are eight carpal bones, divided into two rows of four
The proximal row consists of the scaphoid, lunate, triquetrum, and pisiform bones
The distal row consists of the trapezium, trapezoid, capitate, and hamate bones
The scaphoid bone is the largest bone of the proximal row and articulates with the lower end of the radius

Scaphoid (Navicular)

The scaphoid bone has received its name from its resemblance to a boat
It is situated at the radial site of the wrist
A detailed knowledge of the bones of the hand is unnecessary, but the scaphoid bone is commonly fractured and should be studied

Carpometacarpal Joint of the Thumb

Articulation is between the trapezium and the saddle-shaped base of the first metacarpal bone
The joint is a synovial saddle-shaped joint
The capsule surrounds the joint

Movements of the Carpometacarpal Joint of the Thumb

Abduction is performed by the abductor pollicis longus and brevis
Adduction is performed by the adductor pollicis
Extension is performed by the extensor pollicis longus and brevis
Flexion is performed by the flexor pollicis longus, brevis, and opponens pollicis
Rotation (opposition) is performed by the opponens pollicis

Metacarpophalangeal Joints

Articulation is between the heads of the metacarpal bones and the bases of the proximal phalanges
The joints are synovial condyloid joints
The capsule surrounds the joint

Ligaments of the Metacarpo-phalangeal Joints

The palmar ligaments are strong and contain some fibrocartilage
They are firmly attached to the phalanx but less so to the metacarpal bone
The deep transverse metacarpal ligaments hold the heads of the metacarpal bones together
The collateral ligaments are cordlike bands present on each side of the joints

Description

Learn about the articulation between the glenoid cavity and the upper end of the humerus, including details about the anatomic neck, surgical neck, tuberosities, and bicipital groove. Understand the structures that form the shoulder joint.