The Skeletal System By Kristen Jebulan and Elisha Espino February 27, 2014 Period 3

Skeletal Organization: The Axial Skeleton Skull Cranium Face Hyoid Sternum Vertebral column Ribs Sacrum

Skeletal Organization: The Appendicular Skeleton Clavicle Scapula Humerus Coxa Radius Ulna Phalanges Carpals Metacarpals Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges

Bone Function: Support/Protection Give shape to structures Provide support and protection Examples: bones of skull protect eyes, ears, and brain; bones of lower limbs, pelvis, and backbone support body weight

Bone Functions: Body Movement Blood Cell Formation

Bone Function: Storage of Inorganic Salts Calcium salts are released from ECM into blood after osteoclasts are stimulated when blood is low in calcium Homeostatic mechanism Maintains sufficient blood calcium levels for muscle contraction, nervous impulse conduction, etc.

Differences between Bonesand Ligaments Tendons Cartilage

The Long Bone Proximal Epiphysis Distal epiphysis Diaphysis Articular cartilage Spongy bone Compact bone Endosteum Periosteum Medullary cavity

Bone Development

Osteoblasts bone-forming cells. Called “osteocytes” when extracellular matrix (ECM) completely surrounds the osteoblasts. Osteoclasts Large, multinucleated cells that break down the calcified ECM. Secrete an acid that dissolves inorganic component of the calcified matrix

Joints Fibrous Dense connective tissue No movement Cartilaginous Hyaline cartilage Limited movement Synovial Cartilage, synovium, synovial fluid Free movement

Synovial Joint Types Ball-and-socket All planes; rotation Ball-shaped with cup Condyloid Variety; no rotation Oval condyle and elliptical cavity Gliding Sliding/twisting Articulating surfaces; flat/curved

Synovial Joint Types (con.) Hinge Flexion and extension Convex surface fits into concave surface of other Pivot Rotation around central axis Cylindrical surface of a bone rotates within a ring Saddle Variety of movement Articulating surfaces have both concave and convex regions

Types of Joint Movement

Types of Joint Movement (con.)

Bone Diseases Arthritis Inflammation in the joint that causes pain Treatable, but not curable Can originate from genetic makeup, constant physical-demanding activity on joint, obesity, etc. Osteoporosis Bone become weak and are more likely to break Treatable, but not curable Can originate from aging, smoking, drinking, low body weight, gender (women), medication use, etc.