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The Skeletal System

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The Skeletal System Due in Lab 1. Skeletal System 33-34 2. Skeletal System 26 3. PreLab 6 Due next week in lab - Scientific America Article Select one article to read and complete article summary Cell Defenses and the Sunshine Vitamin (Summary in Case Study 19-20) Skin Deep (Summary in Case Study 21-22) Sex and the Secret Nerve (Instructor website) The Naked Truth (Instructor website) The Skeletal System Introduction Cranium Skull Facial bones Clavicle Thoracic cage Scapula (ribs and Sternum sternum) Rib Humerus Vertebra Vertebral Radius column Ulna Sacrum Carpals Phalanges Metacarpals Femur Patella Tibia Fibula Tarsals Metatarsals (a) Anterior view Phalanges Functions 1. Support For the body and soft organs 2. Protection For brain, spinal cord and vital organs 3. Movement Levers for muscle action 4. Mineral reservoir Calcium and phosphorus 5. Hematopoiesis Marrow cavities Bone Osseous tissue Hydroxyapatite (85%) Calcium carbonate (10%) Inorganic minerals Magnesium, sodium, fluoride Organic material Collagen Chondroitin sulfate Bone consists of Endosteum multiple tissues A single bone may be considered an organ Yellow bone marrow Compact bone Periosteum Perforating (Sharpey’s) fibers Nutrient arteries (c) Figure 6.3c Articular cartilage Compact bone Proximal epiphysis Spongy bone Epiphyseal line Periosteum Compact bone Medullary cavity (lined (b) by endosteum) Diaphysis Bones are organs comprised of more than just osseous tissue Distal epiphysis (a) Figure 6.3a-b Bone Classification Figure 6.2 General Bone Features Long bone anatomy (Humerus) Diaphysis Epiphysis Metaphysis Epiphyseal growth plate or line Articular cartilage Periosteum Medullary cavity Endosteum Articular cartilage Compact bone Proximal epiphysis Spongy bone Epiphyseal line Periosteum Compact bone Medullary cavity (lined (b) by endosteum) Diaphysis Anatomy of a long bone Distal epiphysis (a) Figure 6.3a-b Endosteum Outer layer of periosteum = dense irregular fibrous sheath Yellow bone marrow Compact bone Periosteum Perforating (Sharpey’s) fibers Nutrient arteries (c) Figure 6.3c Articular cartilage Compact bone Proximal epiphysis Spongy bone Epiphyseal line Periosteum Compact bone Medullary cavity (lined (b) by endosteum) Diaphysis Epiphyseal line is a remnant of the epiphyseal plate Distal epiphysis (a) Bone Histology Components Cells Fibers Ground substance Bone Histology Cells Osteogenic (osteoprogenitor) cells Stem cells in periosteum and endosteum → osteoblasts Osteoblasts Bone forming cells (a) Osteogenic cell (b) Osteoblast Stem cell Matrix-synthesizing cell responsible for bone growth Figure 6.4a-b Bone Histology Cells Osteocytes Mature bone cells Maintain bone matrix Osteoclasts Break down (resorb) bone matrix Related to macrophages (c) Osteocyte (d) Osteoclast Mature bone cell Bone-resorbing cell that maintains the bone matrix Figure 6.4c-d Spongy bone (diploë) Compact bone Compact bone covers all spongy bone and the shafts Trabeculae of long bones Figure 6.5 Bone Histology Primary bone types Compact Spongy Articular cartilage Compact bone Proximal epiphysis Spongy bone Epiphyseal line Periosteum Compact bone Medullary cavity (lined (b) by endosteum) Diaphysis Distal epiphysis (a) Figure 6.3a-b Compact Spongy bone bone Central Perforating (Haversian) canal (Volkmann’s) canal Endosteum lining bony canals Osteon and covering trabeculae (Haversian system) Circumferential lamellae (a) Perforating (Sharpey’s) fibers Lamellae Periosteal blood vessel Periosteum Nerve Vein Artery Lamellae Central Canaliculi Lacuna (with canal osteocyte) Osteocyte Lacunae in a lacuna (b) (c) Interstitial lamellae Figure 6.7a-c Artery with capillaries Structures in the Vein central Nerve fiber canal Lamellae Collagen fibers run in different directions Twisting force Figure 6.6 Nerve Vein Lamellae Artery Central Canaliculus canal Osteocyte Lacunae in a lacuna (b) Figure 6.3b Spongy bone (diploë) Compact bone Trabeculae Figure 6.5 Bone Histology Bone marrow Location Medullary cavity and spaces between trabeculae Bone Histology Bone marrow Types Red Red blood cells Hematopoiesis Yellow Replaces red with age Fat storage Gelatinous Mostly water and protein Skeletal System 17 Label the following Proximal epiphysis Periosteum Distal epiphysis Endosteum Epiphyseal line Diaphysis Articular cartilage Nutrient artery Spongy bone Marrow Compact bone Perforating (Sharpey’s) Medullary canal fibers Turn in Skeletal System 19 Table 6.1 Skeletal System 19 Table 6.1 Table 6.1 .
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