CHP7 Bone Tissue

Table 74 bone ratio of 2 depends on amount of

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Unformatted text preview: childhood disease where Ca salts deficient childhood causing soft/bendable bones that deform due to inc body wgt wgt • Protein allows for flexibility…no protein can lead to brittle Protein bone disease, etc. (Table 7.4) bone • Ratio of 2 depends on amount of tension/compression Ratio exerted on various bones exerted Compact bone Compact Recall that histological studies include dry bone, & so, cells & Recall organic matter destroyed but inorganic matrix remains organic Osteon (haversian system)= basic structural unit, includes central canal & lamellae • Central canal= houses bld vessels, nerves • Lamellae= concentric layers of matrix around central canal • Collagen fibers alternate between right- and left-handed helices from lamella to lamella to inc strength of bone • Canaliculi= tiny processes that connect osteocytes to each other (share blood supply, info, etc.) Compact Bone (cont.) Compact Additional features of compact bone~ • Perforating canals or Volkmann canals= vascular canals that run perpendicular in bone & supply central canals • Enter bone thru nutrient foramina • Gap junctions w/in innermost osteocytes move nuts/wates to/from neighboring osteocytes • Circumferential lamellae= runs parallel to bone surface on runs inner & outer boundaries of dense bone inner • Interstitial lamellae= remains of old osteons remains Spongy Bone & Bone Marrow Spongy Spongy bone= spongelike appearance formed by rods and plates of bone (trabeculae) • • • • • Red bone marrow fills spaces Matrix of trabeculae arranged in lamellae but few osteons Central canals not needed as osteocytes near marrow Trabeculae develop along bone’s lines of stress Provides strength with little weight Bone marrow= soft tissue w/in medullary cavity, spaces of trabeculae, & larger central canals • 3 kinds of marrow= red, yellow, & gelatinous Bone marrow (cont.) Bone Red marrow= ‘‘myeloid tissue’ that produces blood myeloid (hemopoietic); looks like thick blood (hemopoietic); • Mesh of reticular fibers ‘saturated’ w/ immature cells & Mesh scattered adipocytes scattered • Found in vertebrae, ribs, sternum, pelvic girdle and proximal Found heads of femur & humerus in adults in Yellow marrow= fatty marrow of long bones in adults Yellow • Most red marrow of kids changes to yellow • No longer makes bld, but can change back if needed No Gelatinous marrow= ‘‘r...
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This note was uploaded on 01/12/2014 for the course ZOO 250 taught by Professor Staff during the Fall '08 term at S.E. Louisiana.

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