The Skeletal System: A Closer Look

Type of Bone Example Function in Sport Long Short Flat Irregular Sesamoid Femur, Humerus Movement - to generate strength and speed Carpals, tarsal Shock absorption - spreading load Cranium: Frontal, Parietal, Occipital , Temporal Protection of vital organs, attachment of muscles to help movement Vertebrae Provide shape, protection Patella Provide protection

Bone Cells Osteocytes: bone cells Osteoblasts: bone-building cells Osteoclasts: bone-destroying cell http://ratherrapid.blogspot.com/2008/07/mineralization-in-canon-bone.html

http://www. iofbonehealth http://www.iofbonehealth.org/health-professionals/about-osteoporosis/basic-bone-biology.html

Growth & Formation of Bones Ossification – bone formation Compact bone (begin as cartilage) Osteoblasts discharge osteoid into which minerals are deposited to form hardened material recognized as bone Cancellous bone (begin as fibrous membranes) Osteoblasts release osteoid into membrane which forms a sponge-like bundle of fibre Cancellous bone formation outward from these centres in the membrane

http://lis.arc.nasa.gov/lis2/chapter4_programs/nih_c/nih_c1.html

Bone Remodelling Bones cannot grow by cell division Most active during childhood Process (cycle): Bone resorbing – remove old bone by releasing acids and enzymes Protein secreting – deposit new tissue OSTEOCLAST OSTEOBLAST

http://www.nature.com/pcan/journal/v7/n2/fig_tab/4500705f1.html

Effect of Aging Affects overall calcium levels in the body Gradual decline after 35 As age increases, resorption > reformation Affects overall calcium levels in the body Osteoporosis (low bone mass and deterioration of the bone tissue) may result from resorption Leads to bone fragility Increased susceptibility to bone fractures

How Do We Grow? Epiphyseal plates (growth plates) Occur at various locations at the epiphyses of long bones Growth possible Epiphyseal lines Occur when epiphyseal plates have fused or come together Growth not possible Epiphyseal line Epiphyseal plate

http://www.gla.ac.uk/ibls/US/fab/tutorial/generic/bone5.html

Types of Fractures Stress fracture – most difficult to detect Simple fracture – no separation (hairline fracture) Compound fracture – bone breaks into separate pieces Comminuted fracture – bone shatters into many pieces Simple fracture Compound fracture Comminuted fracture

Prevention Question: What is a preventative measure that you can take to prevent osteoporosis? Please post on FORUM Research about unique innovative ways of maintaining bone health (i.e. Certain diets, specific weight bearing exercises, etc)