Appendicular Skeleton The Upper Limbs The Upper Limbs

Appendicular Skeleton The Upper Limbs

The Upper Limbs – Shoulder Girdle • Shoulder Girdle (aka Pectoral Girdle) contains two bones: clavicle and scapula • Clavicle makes up the collarbone – Attaches to manubrium medially (sternal end) at the sternoclavicular joint – Attaches to scapula laterally (acromial end) at acromioclavicular joint – Serves to push arm back from thoracic cage and helps prevent shoulder dislocation

The Upper Limbs – Shoulder Girdle Anterior View Superior View

The Upper Limbs – Shoulder Girdle • The Scapulae are the shoulder blades – Attached to clavicles, but held loosely in place by muscles – Triangular shape with three sides (Superior border, Medial border, and Lateral border) and three angles (Superior angle, Lateral angle, and Inferior angle) – Suprascapular notch on superior border allows nerves to pass over scapula – Spine is ridge on top half of posterior side of scapula – Lateral end of spine is Acromion process – Coracoid process is inferior and anterior to acromion – Acromion and coracoid processes make the superior border of the Glenoid cavity (the socket for the arm)

The Upper Limbs – Shoulder Girdle Anterior View Posterior View

The Upper Limbs – Arm • The arm consists of one long bone—the Humerus – The rounded Head of the humerus fits in the glenoid cavity of the scapula – Lateral to the head are the Greater and Lesser tubercles, which serve as sites of muscle attachment – Partway down the bone is the Deltoid tuberosity for the deltoid (shoulder) muscle to attach – The Radial groove, which goes by the deltoid tuberosity, marks the path of the radial nerve – The distal end includes the Trochlea and Capitulum that articulate with the bones of the forearm – The Coronoid and Olecranon fossae are depressions that allow the forearm bone Ulna to move when bending and extending the elbow

The Upper Limbs – Arm Anterior View – Right Arm Posterior View – Right Arm

The Upper Limbs – Forearm • The Forearm includes two bones--the Radius and the Ulna – The Forearm bones articulate at both ends by radioulnar joints – The bones are connected by interosseous membrane – The radius is the lateral bone in the anatomical position (same side as thumb) • The flattened head forms a joint with the capitulum of the humerus • Below the head, on the anterior side is the Radial tuberosity where the bicep muscle attaches

The Upper Limbs – Forearm – The ulna is the medial bone in the anatomical position • On the proximal end are the Olecranon and Coronoid processes which articulate with the fossae of the humerus • In between the processes is the Trochlear notch that glides along the trochlea of the humerus

The Upper Limbs – Forearm Anterior View – Right Arm Posterior View – Right Arm

The Upper Limbs – Forearm Posterior View – Right Arm Anterior View – Right Arm

The Upper Limbs – Hand • The hand consists of the Carpals, Metacarpals, and Phalanges • The carpals make up the wrist – The wrist, or carpus, is made of 8 short bones that are lined up in 2 irregular rows – The carpal bones are bound tightly by ligaments that allow minimal movement • The 5 metacarpal bones make up the palm • The phalanges are the finger bones – 14 bones total – Bones are labeled Proximal, Middle, and Distal for each finger (thumb only has proximal and distal as there are only two bones)

The Upper Limbs – Hand