ORGANIZATION OF THE SKELETON

Organization Skeleton – interconnected frame containing 206 bones Axial skeleton – contains bones that lie within the midvertical axis Appendicular Skeleton – contains bones that lie outside the midvertical axis and are associated with the limbs.

Surface Features of Bones Condyle – “knuckle” or a large, rounded prominence Crest – narrow, ridge-like projection Epicondyle – projection above a condyle Facet – smooth articular surface Fissure – narrow opening or cleft

Surface Features of Bones Fosa – depression or groove Process – projection from the surface of a bone Fovea- tiny pit or depression Sinus – cavity within a bone

Surface Features of Bones Spine – narrow or pointed projection Trochanter – large or blunt process Tubercle – small, rounded process Tuberosity – rounded, elevated area of bone that is usually roughened Meatus- tube-like passageway within a bone

AXIAL SKELETON

Skull Cranium bones – 8 bones Facial bones - 13 immovable bones Features: – Sutures – rigid, narrow joints between bones – Sinuses – chambers lined with mucous membranes and filled with air. Connect with nasal cavity to drain fluids. 4 Pairs

Skull bones Frontal – forehead Ethmoidal – nasal Sphenoidal- nasal Maxillary – cheeks Sinusitis – infection of the sinuses, swelling of mucous membranes

Hyoid Bone Small bone in the back of neck Only bone that does not touch another bone

Vertebral Column Runs from base of skull to pelvis Series of irregular bones – vertebrae Between each vertebra is a mass of fibrocartilage called an intervertebral disk Protects the spinal cord – housed inside vertebral canal Total of 33 vertebrae