1. Chapter 5 The Skeletal System Provides an internal framework for the body, protects organs by enclosure, and anchors skeletal muscles so that muscle contractions can cause movement

2. The Skeletal System  Divided into two divisions  Axial skeleton  Longitudinal axis  Bones of the skull, vertebral column, bony thorax  Appendicular skeleton  Bones of the upper & lower limbs, shoulder, & hip

4. The Skeletal System  Parts of the skeletal system  Bones (skeleton)  Joints  Cartilages  Ligaments  Fibrous cords that bind bones together at joints

5. Functions of the Bones  Support the body  Protection of soft organs  Movement  Bones are attached to skeletal muscles by tendons  Storage of minerals and fats  Calcium & phosphorus  Blood cell formation  Hematopoiesis

6. Classification of Bones  Adult skeleton is composed of 206 bones  Two basic types of osseous (bone) tissue  Compact bone  Dense, smooth, & homogeneous  Spongy bone  Small needle-like pieces of bone  Lots open spaces

7. Classification of Bones: Based on Size & Shape

8. Classification of Bones  Long bones  Typically longer than they are wide  Shaft with heads at both ends  Mostly compact bone Examples: Femur, humerus

9. Classification of Bones  Short bones  Generally cube-shaped  Contain mostly spongy bone  Examples: Carpals, Tarsals

10. Classification of Bones  Flat bones  Thin, flattened & usually curved  2 thin layers of compact bone sandwiching a layer of spongy bone  Examples: Skull, ribs, sternum

11. Classification of Bones  Irregular bones  Irregular shape  Do not fit into other bone classification categories  Example: Vertebrae and hip

13. Structure of a Long Bone Gross Anatomy  Diaphysis  Shaft  Composed of compact bone  Covered & protected by the periosteum  Epiphyses  Ends of the bone  Thin layer of compact bone enclose an area filled with spongy bone  Covered by articular cartilage

14. Structure of a Long Bone  Epiphyseal line  Remnant of the epiphyseal plate  Flat plate of hyaline cartilage  Seen in a young, growing bone  Epiphyseal plates  Cause the lengthwise growth of a long bone

15. Structure of a Long Bone  Periosteum  Outside covering of the diaphysis  Fibrous connective tissue membrane  Sharpey’s fibers  Secures the periosteum to underlying bone  Arteries  Supply bone cells with nutrients

16. Structure of a Long Bone  Articular cartilage  Covers the external surface of the epiphyses  Made of hyaline cartilage  Decreases friction at joint surfaces

17. Structure of a Long Bone  Medullary cavity  Cavity of the shaft  Contains yellow marrow (mostly adipose) in adults  In adult bones, red marrow is confined to the cavities of spongy bone of flat bones & epiphyses of some long bones  Contains red marrow (for blood cell formation) in infants

18. Soft, spongy tissue found inside bones Soft, spongy tissue found inside bones Medium for development & storage of the body’s blood cells Medium for development & storage of the body’s blood cells Blood cells that produce other blood cells  Stem cells Blood cells that produce other blood cells  Stem cells Bone Marrow Transplants Bone Marrow Transplants Special therapy for patients with cancer or other diseases which affect the bone marrow Special therapy for patients with cancer or other diseases which affect the bone marrow Leukemias, severe aplastic anemia, lymphomas, multiple myeloma Leukemias, severe aplastic anemia, lymphomas, multiple myeloma Immune deficiency disorders Immune deficiency disorders Solid- tumor cancers Solid- tumor cancers Breast Breast Ovarian Ovarian

19. Involves taking cells that are normally found in the bone marrow (stem cells), filtering those cells, & giving them back to either the patient or to another person Involves taking cells that are normally found in the bone marrow (stem cells), filtering those cells, & giving them back to either the patient or to another person Goal: Goal: Transfuse healthy bone marrow cells into a person after their own unhealthy bone marrow has been eliminated Transfuse healthy bone marrow cells into a person after their own unhealthy bone marrow has been eliminated

20. Leukemia Leukemia Stem cells produce an excessive number of defective or immature blood cells Stem cells produce an excessive number of defective or immature blood cells To eliminate the cancer, high doses of chemotherapy (sometimes radiation) are administered To eliminate the cancer, high doses of chemotherapy (sometimes radiation) are administered Destroys the abnormal stem cells & blood cells Destroys the abnormal stem cells & blood cells However, normal cells found in bone marrow are also damaged However, normal cells found in bone marrow are also damaged Healthy bone marrow is then transplanted to restore normal stem cell function Healthy bone marrow is then transplanted to restore normal stem cell function

21. Autologous bone marrow transplants Autologous bone marrow transplants Your own bone marrow is harvested, preserved & stored (frozen) Your own bone marrow is harvested, preserved & stored (frozen) Then, after high-dose chemotherapy and/or radiation therapy Then, after high-dose chemotherapy and/or radiation therapy Your own bone marrow is infused back into your body Your own bone marrow is infused back into your body This is possible if the disease affecting the bone marrow is in remission, or if the condition being treated doesn't involve the bone marrow (as in breast cancer) This is possible if the disease affecting the bone marrow is in remission, or if the condition being treated doesn't involve the bone marrow (as in breast cancer) Allogeneic bone marrow transplants Allogeneic bone marrow transplants Bone marrow is harvested from a family member or an unrelated donor Bone marrow is harvested from a family member or an unrelated donor

22. Bone Marrow Harvesting Bone Marrow Harvesting Bone marrow is withdrawn through a needle inserted into a bone in the hip Bone marrow is withdrawn through a needle inserted into a bone in the hip Performed in the operating room Performed in the operating room Patient is given general anesthesia Patient is given general anesthesia If your own bone marrow can not be used for transplantation and if a donor is not found, peripheral stem cells may be harvested from your circulating blood If your own bone marrow can not be used for transplantation and if a donor is not found, peripheral stem cells may be harvested from your circulating blood What happens during the transplant? What happens during the transplant? The day you receive your bone marrow transplant, the harvested bone marrow is infused into a vein (IV) The day you receive your bone marrow transplant, the harvested bone marrow is infused into a vein (IV) Bone marrow looks like dark, thick blood Bone marrow looks like dark, thick blood It migrates to the large bone cavities (breast bone, skull, hips, ribs, and spine), engrafts, and begins producing normal blood cells after several weeks It migrates to the large bone cavities (breast bone, skull, hips, ribs, and spine), engrafts, and begins producing normal blood cells after several weeks

24. Microscopic Anatomy of Compact Bone Compact Bone Tissue * Riddled with passageways carrying nerves & blood vessels  provide the living bone cells with nutrients & a route for waste disposal

25. Microscopic Anatomy of Compact Bone  Lacunae  Cavities containing bone cells  Osteocytes = mature bone cells  Arranged in concentric rings called lamellae  Lamellae  Concentric rings around the central (Haversian) canals

26. Microscopic Anatomy of Compact Bone  Osteon (Haversian System)  Complex consisting of the central canal & matrix rings  Central (Haversian) canals  Run lengthwise through the bony matrix  Carrying blood vessels and nerves to all areas of the bone  Perforating (Volkmann’s) canals  Canals perpendicular to the central canal  Carry blood vessels & nerves

27. Microscopic Anatomy of Compact Bone  Canaliculi  Tiny canals  Radiate outward from the central canals to all lacunae  Form a transportation system  Connects all bone cells to the nutrient supply

29. Bone Markings  Surface features of bones  Reveal sites of attachment for muscles, tendons, & ligaments  Conduits for blood vessels & nerves  Two categories of bone markings  Projections (processes)  Grow out from the bone surface  Depressions (cavities)  Indentations in the bone

30. The Axial Skeleton