Appendicular Skeleton

Consists of the bones of the upper and lower limbs as well as the girdles, which attach the limbs to the axial skeleton.

Pectoral Girdle Consists of four bones, two scapula and two clavicles. These attach the upper limbs to the body.

Scapula A flat, triangular bone with three large fossae where muscles extending to the arm are attached. Has an infraspinous fossa, the subscapular fossa and the supraspinous fossa. A fourth fossa, the glenoid fossa is the point of articulation with the head of the humerus.

A ridge called the spine runs across the posterior surface of the scapula. A prominent projection called the acromion process extends from the scapular spine to the point of the shoulder. This process is the point of articulation with the clavicle. The coracoid process curves below the clavicle and is the point of attachment for arms and chest muscles.

Scapula

Upper limb Consists of the arm, forearm, wrist and hand.

Arm Between the shoulder and the elbow, this is the humerus. Proximal end had the head, which attaches the humerus to the scapula at the glenoid fossa. Running right around the end of the humeral head is the anatomical neck.

The surgical neck is at the proximal end of the humeral shaft The surgical neck is at the proximal end of the humeral shaft. Just below the anatomical neck. The greater and lesser tubercles are lateral to the head. Muscles attaching here hold the humerus to the scapula.

The deltoid tuberosity is about 1/3 the distance down the shaft on the lateral surface and is the point of attachment for the deltoid muscle. Distally, the humerus is modified into specialized condyles that connect the humerus to the forearm bones.

The lateral and medial epicondyles are found lateral to the condyles and provide attachment sites for forearm muscles. The olecranon fossa is superior to the trochlea. The olecranon fossa allows articulation with the ulna. The coronoid fossa also allows articulation with the ulna.

The capitulum is the ball shaped structure at one end of the trochlea. The capitulum articulates with the radius and the trochlea with the ulna.

Humerus

Forearm Consists of two bones, the ulna (medial) and the radius (lateral). Proximal end of ulna forms a semilunar notch that fits tightly over the end of the humerus. Proximal to the semilunar notch is the olecranon process (elbow).

Distal to the semilunar notch is the coronoid process, which also helps hold the humerus in place. Distal end of the ulna forms a head, articulating with the wrist bones. It can be felt as a prominent lump on your wrist. A styloid process can be felt on its medial side.

The proximal end of the radius has a head which articulates with the humerus and the ulna. This provides a rotating motion. Distal to the radial head is a radial tuberosity where the biceps brachii attaches.

A styloid process is on the lateral side of the distal end of the radius. The radial and ulnar styloid processes provide attachments for ligaments of the wrist.

Forearm

Wrist Consists of eight carpal bones: Scaphoid Lunate Triquetrum Pisiform Trapezium Trapezoid Capitate Hamate

Arranged in two rows of four that curve slightly.

Hand Consists of five metacarpals. Are aligned with the five digits (thumb and fingers). Metacarpals are numbered 1 to 5 from thumb to little finger. Knuckles are formed by the ends of the metacarpals.

Each finger consists of three bones called phalanges; proximal, middle and distal. Thumb has two phalanges; proximal and distal. Digits are numbered 1 to 5 from thumb to little finger.