The Appendicular Skeleton Composed of 126 bones Appendages (limbs- arms and legs) Pectoral girdle (holds your arms to the body) Pelvic girdle (holds your legs to the body) The Appendicular Skeleton

The Appendicular Skeleton Figure 5.6b

The Pectoral (Shoulder) Girdle Composed of two bones Clavicle—collarbone Scapula—shoulder blade These bones allow the upper limb to have exceptionally free movement The Pectoral (Shoulder) Girdle

Bones of the Shoulder Girdle Clavicle Figure 5.21b

Sternal end – articulates with the manubrium of the sternum; has a broad, flat surface. Acromial end – articulates with the arcomion process of the scapula; has a thin, curved surface. Clavicle

Bones of the Shoulder Girdle Scapula Figure 5.21c–d

Acromion process – enlarged end of the spine; articulates with clavicle. Coracoid process – other beak like projection that points over the top of the shoulder and anchors muscles of the arm. Glenoid Cavity – shallow socket that receives the head of the arm bone (humerus). Spine – Ridged projection on posterior surface. Supraspinous fossa – depressed area above spine. Infraspinous fossa – depressed area below spine. Scapula

Medial border, Lateral border, superior border self- explanatory Inferior angle – most inferior “point” Superior angle – most superior “point” that is not the acromion or coracoid Scapula

Bones of the Upper Limbs Humerus Forms the arm Single bone Bones of the Upper Limbs

Humerus Head – rounded end; fits in glenoid cavity of scapula. Anatomical Neck – inferior to head; slight constriction. Greater & lesser tubercles – muscle attachments Intertubercle Groove – anterolateral to head; separates greater and lesser tubercles. Deltoid tuberosity – midpoint of shaft; roughened area that is site of attachment for deltoid muscle Humerus

Medial and Lateral Epicondyles – flank depressions at distal end of humerus; allow ulna to move freely when elbow is bent and extended. Coronoid fossa – anterior depression for coronoid process of ulna Radial fossa – lateral to coronoid fossa; articulates with radial head. Olecranon fossa – posterior depression for olecranon process of ulna Humerus

Capitulum – rounded knob lateral to Capitulum – rounded knob lateral to trochlea, articulates with head of radius Trochlea – rounded spool-shaped medial distal end, articulates with ulna Humerus

Bones of the Upper Limbs Ulna and Radius The forearm has two bones Ulna Medial bone in anatomical position Radius Lateral bone in anatomical position Bones of the Upper Limbs Ulna and Radius

Radius (thumb/lateral side) Head – disc-shaped; forms joint with capitulum of humerus Radial tuberosity – bump, below head of radius, attachment point for tendons of bicep muscle Ulnar Notch – articular surface at distal end; narrow, concave, smooth, and articulates with the distal end of the ulna forming the distal radioulnar joint Styloid process – palpable projection on distal end Radius (thumb/lateral side)

Ulna (medial/pinky side) Olecranon process - proximal end, posterior projection that makes up elbow. Coronoid process – proximal end, anterior projection that makes up the elbow. Trochlear notch - separate coronoid and olecranon processes; toward medial side Radial notch - narrow, oblong, articular depression on the lateral side of the coronoid process; it receives the head of the radius. Ulna (medial/pinky side)

Ulna (medial/pinky side) Head - adjacent to styloid process at distal end; forms distal radioulnar joint. Styloid process - distal end, projects from the medial and back part of the bone; it descends a little lower than the head, and its rounded end affords attachment to a ligament of the wrist. Ulna (medial/pinky side)

Bones of the Upper Limbs Carpals, Metacarpals,Phalanges The hand Carpals—wrist Metacarpals—palm Phalanges—fingers Bones of the Upper Limbs Carpals, Metacarpals,Phalanges