THE SKELETAL SYSTEM enter the world of bones

THE SKELETAL SYSTEM is the human body system composed of bones and connective tissue in various sub-systems and formats. WHAT IS THE SKELETAL SYSTEM?

FUNCTIONS OF THE SKELETAL SYSTEM : support for the body protection of vital organs connection of muscle system -which enables movement storage of vital minerals production of blood cells

STRUCTURE OF THE SKELETAL SYSTEM parts, function and variations

ALL ASSIST HUMAN MOVEMENT BONES ● most rigid connective tissue ●inorganic salts connected to protein fibers LIGAMENTS ● connect bones to bones ●present in joints TENDONS ●connect bones to muscles ●dense collections of collagen fibers

The Long Bone

✘ includes the appendages, pelvic girdle, arms, legs, the works ✘ provides locomotion and structure, muscular-skeletal AXIAL ✘ protects the center: skull, thoracic cage ✘ works more to protect vital organs: brain, heart, pelvis, and central nervous system APPENDICULAR

VARIATIONS OF THE SKELETAL SYSTEM ✘ HYDROSTATIC SKELETON - lack of skeletal system, uses water-filled sacks as skeleton -roundworms and earthworms, snails - fluid aids in locomotion ✘ ENDOSKELETON -structural, interior skeleton -humans, echinoderms and vertebrates -calcium carbonate or living tissue ✘ EXOSKELETON -rigid, exterior skeleton -molluscs have calcium carbonate shells for protection -insects have a rigid chitin exoskeleton

skeletal system HOMEOSTASIS

BONE GROWTH AND RENEWAL osteoblasts convert cartilage to hard bone endochondral ossification osteoclasts break down bone regulate blood calcium levels osteocytes replace worn bone areas regulate blood calcium levels

ARTHRITIS o Rheumatoid or osteoarthritis o Degeneration of cartilage in joints o Joint replacement sometimes successful as treatment o Almost 50% of people 85 and up will be diagnosed with osteoarthritis in the knee

"Arthritis-Related Statistics." Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 17 Mar Web. Caplan, Geralyn M. "Skeletal System." Skeletal System. N.p., n.d. Web. Farabee, Michael J., Ph.D. "MUSCULAR AND SKELETAL SYSTEMS." Muscular and Skeletal Systems. Estrella Mountain Community College, 17 Sept Web. Mader, Sylvia S. "Locomotion and Support Systems." Biology. 10th ed. Dubuque, IA: McGraw- Hill, Print. works cited