BIO 446L 1nd Edition Lecture 7 Outline of Last Lecture I. Adipose Tissue Contda. Storage and mobilizationb. Brown fatII. Cartilagea. Hyalineb. Elasticc. Firbrocartilaged. ChondrogenesisIII. Bonea. Compactb. Spongyc. Periosteum and Endosteumd. Bone Cells and MatrixOutline of Current Lecture I. Bone Continueda. Bone cellsi. Osteocytesii. Osteoclastsb. Bone formationi. Woven boneii. Lamellar bonec. Bone repair and remodelingd. Osteogenesisi. Intramembranous ossificationii. Endochondral ossificatione. Interstitial bone growthf. Regulation of bone metabolismCurrent LectureBone Tissue Continued- Bone cellso OsteocytesThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute. Communicate via gap junctions Pick up stress during weight bearing exercises Processes in canaliculi with gap junctions- Canaliculi= how nutrients and oxygen reach trapped osteocytes- Mechanism for sensing loado Can send signal to make bone more or less denseo Osteoclasts Monocytes in bone marrow Resorption bays Activity regulated by calcitonin and indirectly by parathyroid hormone (PTH)- PTH= raises calcium levels- No binding site, binds with osteoblast to stop laying down of matrix and secretes substrate that stimulates clast- bone becomes very dense- Bone formationo Woven bone During embryonic development Bone repair and remodeling Random collagen deposition- laid down in very irregular planes faster but not as strongo lamaller bone once woven is laid down, lamellar will lay down in concentric layers in compound and cancellous- bone repair and remodelingo blood clot forms around breako see slide images- osteogenesiso intramembranous ossification formation of flat bones- frontal and parietal derived from embryonic mesenchyme- condensed mesenchyme will differentiate into clasts/blasts woven bone first - will eventually emerge to form plates- then remodeled by blasts/clasts into lamellaro endochondral ossification long and short bones osteoblasts differentiate from hyaline cartilage model- NOT mesenchyme See slide for steps—be familiar with them Bone collar is created- Cuts off blood supply- Need blood vessels in interior of forming bone- Primary ossification center Periosteum with progenitor cells- Become blasts (appositional) Cartilage at cap calcifies- Interstitial bone growth- Blood supply bring progenitor cells- Interstitial Bone Growtho Epiphyseal plateo See slides for images- Regulation of Bone Metabolismo Calcium homeostasis by PTH, calcitonin, and growth hormoneo Nutrient regulationo Second image: growth hormone excess after epiphyseal plate has closedo Third image: growth hormone shortage/ excess causing dwarfism/ gigantism,
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