Jim, Tyler and Matt

Adult Bones  Adult humans have 206 bones Accounts for ~12-15% of body mass  Some areas have a higher concentration of bones than others: 54 bones in wrists, palms and fingers 52 bones in ankles and toes 14 facial bones 1 throat bone (hyoid)  More than half the bones of the body are in the hands and feet

Adult Bones  Found throughout body Within softer bodily tissues  Variety of sizes, shapes and functions Inner ear bones vs. femur  Provides framework of body  2 divisions of bone Axial skeleton Appendicular skeleton

Axial Skeleton  80 bones  Skull  Vertebral column  Ribs  Maintains upright posture of human body  Protects vital organs

Appendicular Skeleton  126 bones  Shoulder girdles  Upper limbs  Pelvic girdle  Lower limbs  Makes movement possible  Protects major organs of digestion, excretion and reproduction

Types of Bone  Long bones Length>diameter  Short bones Length similar to width, depth and diameter  Flat bones  Irregular bones Complicated shapes  Sesamoid bones

Movement of the Body  Bones and muscles work together to allow the body to move  Various shapes and sizes of bone create different movement  Joints Where 2 or more bones come together

Joints of the Body  Pivot Rotation  Ball and Socket Almost all planes  Hinge Flexion and extension  Ellipsoid Flexion, extension, adduction, abduction and circumduction  Saddle Flexion, extension, adduction, abduction and circumduction  Gliding

Structure of Bone  Consists of two main components Organic- produced as a result of the body Inorganic- “bone mineral”  The combination creates both the strength and flexibility of bone

Organic Component of Bone  Primarily collagen Protein Triple helix= tensile strength About 90-95% of organic component  Other 5-10% is a homogenous liquid called ground substance Mixture of water and proteins Similar to an extracellular matrix, but for the fibers

Inorganic Component of Bone  Primarily formed from salts of calcium and phosphate Major salt is hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 )  Other trace minerals Magnesium Sodium Potassium Carbonate  Provides compressional strength of bone

Chemical Composition of Bone  The exact percentages depend on a variety of factors: Age, gender, ethnicity, health status and bone site