1. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 1 Functions of Skeletal System Provides support Protects organs Movement by working with muscle Stores calcium Forms blood cells— hematopoiesis

2. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 2 Types of Bones Structure of long bones –Diaphysis, or shaft—hollow tube of compact bone –Medullary cavity—space inside diaphysis that contains yellow marrow –Epiphyses, or ends—made of spongy bone that contains red marrow –Articular cartilage—thin layer that covers each epiphysis; –Periosteum—strong membrane covering bone –Endosteum-membrane that lines medullary cavity

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4. 4 Types of Bones Structure of flat bones –Thin layer of compact bone surrounding cancellous (spongy or diploe) bone –Spaces surrounded by boney trabeculae

5. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 5 Microscopic Structure of Bone and Cartilage Bone –Spongy Threads called trabeculae surrounded by open spaces In epiphyses Spaces contain red bone marrow

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7. 7 Microscopic Structure of Bone and Cartilage Bone: Compact –Concentric lamella—circular layers of calcified matrix –Lacunae—spaces in matrix for osteocytes –Canaliculi—passageways that connect lacunae and allow nutrients to reach osteocytes –Central canal of osteon contains blood vessel

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9. 9 Bone Formation and Growth New bone-forming cells are osteoblasts Bone resorbing cells are osteoclasts

10. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 10 Bone Formation and Growth Bone formation –Epiphyseal plate of cartilage between epiphyses and diaphysis remains until skeletal maturity –Epiphyseal line (bone) replaces epiphyseal plate (cartilage) when growth ceases

11. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 11 Microscopic Structure of Bone and Cartilage Cartilage –Chondrocytes located in lacunae –Matrix is flexible gel-like substance and lacks blood vessels

12. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 12 Divisions of Skeleton Axial skeleton (80 bones) –Skull –Spine, or vertebral column –Thorax Appendicular skeleton (126 bones) –Upper extremities, including shoulder (pectoral) girdle –Lower extremities, including hip (pelvic) girdle

13. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. –Spine or vertebral column Four normal curves Three abnormal curves –Lordosis or “swayback” –Kyphosis or “hunchback” –Scoliosis 13

14. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 14 Differences Between a Man’s and a Woman’s Skeleton Size—male skeleton generally larger Shape of pelvis—male pelvis deep and narrow; female pelvis broad and shallow Size of pelvic inlet—female pelvic inlet generally wider; normally large enough for baby’s head to pass through it Pubic angle—angle between pubic bones of female generally wider

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17. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 17 Skeletal Disorders Metabolic bone diseases –Osteoporosis Loss of calcified bone matrix and reduction in number of trabeculae in spongy bone Bones fracture easily, especially in wrists, hips, and vertebrae Treatment :

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19. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 19 Skeletal Disorders Metabolic bone diseases –Rickets and osteomalacia—both diseases characterized by loss of bone minerals related to vit D Rickets –Loss of bone minerals in infants and young children before skeletal maturity –Lack of bone rigidity causes gross skeletal changes (bowing of legs) –Treated with vitamin D

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21. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 21 Skeletal Disorders Metabolic bone diseases –Rickets and osteomalacia Osteomalacia –Mineral content lost from bones that have already matured –Increases susceptibility to fractures –Treated with vitamin D

22. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 22 Skeletal Disorders Metabolic bone diseases –Paget disease (osteitis deformans) Faulty remodeling results in deformed bones that fracture easily Cause may be genetic or triggered by viral infections

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24. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 24 Skeletal Disorders Metabolic bone diseases –Osteogenesis imperfecta (also called brittle bone disease) Bones are brittle because of lack of organic matrix Treatment may include splinting to reduce fracture and drugs that decrease cell activity

25. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 25 Skeletal Disorders Bone infection –Osteomyelitis General term for bacterial (usually staphylococcal) infection of bone Treatment involve surgery, drainage of pus, and antibiotic

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27. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 27 Skeletal Disorders Bone fractures –Open (compound) fractures pierce skin and closed (simple) fractures do not –Fracture types include complete and incomplete, linear, transverse and oblique

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29. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 29 Skeletal Disorders Joint disorders –Noninflammatory joint disorders—do not usually involve inflammation of the synovial membrane; symptoms tend to be local and not systemic Osteoarthritis, or degenerative joint disease (DJD) –Most common noninflammatory disorder of movable joints—often called “wear and tear” arthritis –Symptoms: joint pain, morning stiffness, Bouchard nodes (at proximal interphalangeal joints), Heberden nodes (at distal interphalangeal joints) of the fingers –Most common cause for partial and total hip and knee replacements

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31. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 31 Skeletal Disorders Joint disorders –Noninflammatory joint disorders Traumatic injury –Dislocation or subluxation—articular surfaces of bones in joint are no longer in proper contact –Sprain—acute injury to ligaments around joints (e.g., whiplash type injuries) –Strain—acute injury to any part of the “musculotendinous unit” (muscle, tendon, junction between the two, and attachments to bone)

32. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 32 Skeletal Disorders Joint disorders –Inflammatory joint disorders Arthritis: general name for several inflammatory joint diseases that may be caused by infection, injury, genetic factors, and autoimmunity Inflammation of the synovial membrane occurs, often with systemic signs and symptoms

33. Mosby items and derived items © 2010, 2006, 2002, 1997, 1992 by Mosby, Inc., an affiliate of Elsevier Inc. 33 Skeletal Disorders Joint disorders –Inflammatory joint disorders Rheumatoid arthritis –Systemic autoimmune disease—chronic inflammation of synovial membrane with involvement of other tissues such as blood vessels, eyes, heart, and lungs –Gouty arthritis—synovial inflammation caused by gout, a condition in which sodium urate crystals form in joints and other tissues –Infectious arthritis—arthritis resulting from infection by a pathogen, as in Lyme arthritis and ehrlichiosis, caused by two different bacteria that are transmitted to humans by tick bites

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