Bones and joints of the upper limb

2. The clavicle is the only long bone and develops from . The lateral end of the clavicle is called the of the scapula and is flattened in shape. The medial end of the clavicle is called the , articulates with the manubrium of the sternum and is in shape. The clavicle is an curve with the medial 2/3rds bulging outwards and the lateral 1/3rd bulging inwards, the point in which the clavicle changes shape is vulnerable to . The superior clavicle surface is whilst the inferior clavicle surface is .

3. The scapula is a shaped bone which is on the posterior surface of the thoracic cage. It has 3 borders: the medial, lateral and superior border. The border is closest to the upper limb, the border is closest to the vertebrae. The posterior surface has a separating the supraspinous fossa and infraspinous fossa. The anterior scapular surface has the fossa. The lateral end of the scapular spine is called the . The is the shallow depression which receives the head of the humerus. The is the fibrocartilaginous rim that works to deepen the socket for the glenohumeral joint.

4. The humerus is the long bone of the arm. It has a superior articulation with the at the shoulder and inferior articulation at the with the and . At the proximal end of the scapula, there is a greater tubercle, a lesser tubercle and an groove between them. The neck of the humerus is where the epiphyseal growth plate is located whilst the neck is the region that the humerus changes in diameter, predisposing this region to fracture. The head of the humerus articulates with the of the scapula and is lined by . The humerus is a long bone, thus it has a shaft (diaphysis). The distal humerus has medial and lateral . The epicondyle is more close to the skin. The is adjacent to the medial epicondyle and articulates with the trochlear notch of the ulna and the is adjacent to the lateral epicondyle and articulates with the radius head.

6. The radius lies in the forearm and articulates with the of the humerus. At the proximal end, the radius has a flat, discoid at the elbow, a neck and a radial tuberosity that is the region of insertion of the muscle. Inferiorly, at the wrist, the radius has a .

7. The is the fibrous membrane between the radius and ulna, forms a joint which allows supination and pronation of the arm and provides a large surface area as a site of muscle attachment.

8. The hand has 29 bones. There are carpal bones, 5 metacarpals and phalanges. The proper name for knuckles is the joint. A sesamoid bone is formed in the of a muscle and is found in the thumb.

9. Joints can be classified based on the type of interlinking substance. Fibrous joint examples are the of the skull and the between the radius and ulna. These allow for relatively limited movement. Cartilaginous joint examples include the of the thoracic cage and the of the spine. Synovial joints allow for the most movement and examples include the ball and socket joints of the hip and shoulder.

13. The 3 joints of the girdle include the sternoclavicular, acromioclavicular and glenohumoral joint.

The ulna lies medially in the forearm and articulates with the of the humerus. The head of the ulna is inferior and at the wrist, whilst the head of the is and at the elbow. The trochlear notch of the ulna has a lower lip called the and an upper lip called the . The trochlear tuberosity is under the trochlear notch and is for the insertion of the muscle.

11. Joints can be classified based on how many planes they allow movement in. Examples of uniaxial joints includes the joint of the elbow (allows flexion and extension) and the joint of the interosseous membrane (allows supination and pronation), examples of biaxial joints include the joints of the wrist (allowing adduction, abduction, flexion and extension). Examples of multi-axial joints include ball and socket joints and the saddle joint of the thumb which is between the and metacarpal bones.