Chapter 7 Histology of Osseous Tissue - PDF

Chapter 7 pgs 197-206; pgs 209-213 Histology of Osseous Tissue; Bone Development; Physiology of Osseous Tissue ©McGra...

Chapter 7 pgs 197-206; pgs 209-213 Histology of Osseous Tissue; Bone Development; Physiology of Osseous Tissue ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written  Section 7.1 Tissues and Organs of the Skeletal The major functions System of bone and the skeletal system. Support—limb bones and vertebrae support body; jaw bones support teeth; some bones support viscera Protection—of brain, spinal cord, heart, lungs, and more Movement—limb movements, breathing, and other movements depend on bone Electrolyte balance—calcium and phosphate levels Acid–base balance—buffers blood against large pH changes by altering phosphate and carbonate salt levels Blood formation—red bone marrow is the chief producer of blood cells ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written  Section 7.1 Tissues and Organs of the Skeletal System Bone (osseous tissue) is connective tissue. The matrix is hardened by calcium phosphate and calcium carbonate through a process of Mineralization or calcification. Individual bones are organs. They consist of bone tissue, bone marrow, cartilage, adipose tissue, nervous tissue, blood, myeloid, and fibrous connective tissue. ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written  General Features of Bones Long bone – Epiphyses and diaphysis – Compact and spongy bone – Marrow cavity – Articular cartilage – Periosteum ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written  1. Compact bone—dense outer shell of bone 2. Spongy (cancellous) bone—loosely organized bone tissue 3. Diaphysis—shaft that provides leverage 4. Medullary cavity (marrow cavity)— space in the diaphysis of a long bone that contains bone marrow 5. Epiphyses—enlarged ends of a long bone 6. Epiphyseal plate (growth plate)—area of hyaline cartilage that separates epiphyses and diaphyses of children’s bones – Enables growth in length – Epiphyseal line—in adults, a bony scar that marks ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written 7. Articular cartilage—layer of hyaline cartilage that covers joint surface; allows joint to move more freely 8. Nutrient foramina—minute holes in bone surface that allows blood vessels to penetrate 9. Periosteum—external sheath of bone made of outer fibrous layer of collagen with Perforating fiber that penetrate into bone matrix Inner osteogenic layer of bone-forming cells that is Important for bone growth and healing of fractures 10. Endosteum—thin layer of reticular connective tissue lining marrow cavity – Has cells that dissolve osseous tissue and others that deposit it ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written  Gross Bone Architecture Based Structure Outer Edge of the Bone Periosteum Perforating Fibers Compact Bone arranged in circumferential orientation Haversian Systems with central canals Trabeculae of th Spongy Bone Endosteum Inner Edge of the Bone surrounding the marrow canal ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written  Fine Bone Architecture Based on Cell Types Outer Edge of the Bone Periosteum Layer of Dense Fibrous Regular CT Layer of Osteogenic Cells Layer of Osteoclasts Resorption Bay Bone Tissue (Multiple Layers of Osteons) arranged in either a Concentric or Circumferential Lamellae Layer of Osteogenic Cells Endosteum Inner Edge of the Bone surrounding the marrow canal ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written  Covers all portions of compact bone except at the joint cavities Has outer fibrous layer and inner cellular layer Isolates bones from surrounding tissues Provides route for blood vessels and nerves Participates in bone growth and repair Continuous with other connective tissues that mesh with tendons and ligaments Perforating fibers bond tendons and ligaments into the general structure of the bone. ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written 3. The Endosteum The endosteum consists of an incomplete cellular layer. It lines the marrow cavities. It covers the trabeculae of spongy bones. It lines the inner surfaces of central canals It is active during bone growth, repair, and remodeling. ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written 7.2 Histology of Osseous Tissue Bone is connective tissue that consists of cells, fibers, and ground substance. Four principal types of bone cells include: Osteogenic cells Osteogenic cells Osteoblasts Osteocytes Osteoclasts Bone Deposition Bone Resorption ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written  Bone Cells 1. Osteogenic cells—stem cells found in endosteum and inner layer of periosteum – Function: Multiply continuously give rise to the osteoblasts. 2. Osteoblasts—bone-forming cells responsible for osteogenesis – Form single layer of cells under endosteum and periosteum – Nonmitotic – Function: Synthesize soft organic matter of matrix which then hardens by mineral deposition – Function: Stress stimulates osteogenic cells to multiply rapidly and increase the number of osteoblasts which reinforce bone ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written  Bone Cells 3. Osteocytes—former osteoblasts that have become trapped in the matrix they deposited – Lacunae—tiny cavities where osteocytes reside – Canaliculi—little channels that connect lacunae Cytoplasmic processes or dendrites of osteocytes reach into canaliculi and contact processes of neighboring cells Gap junctions allow for passage of nutrients, wastes, signals Osteocytes act as strain sensors—when stressed, produce biochemical signals that regulate bone ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written  Osteocytes and Osteoblasts secrete hormone Osteocalcin Stimulates Influenc Inhibits Insulin es Male a) Parasympathetic secretion Fertility Promotes Innervation by the protein during stressful Pancreas synthesis situations such and as “Flight or muscle Fight.” Insulin stimulates adipose tissue in the following ways: maintenan a) it decreases the rate of ce lipolysis in adipose tissue and hence lowers the plasma fatty osteocalcin-deficient acid level, b) mice were found to be b) (b) it stimulates fatty acid and Promotes increased anxiety and triglyceride synthesis in glucose decreased memory tissues, metabolis more passive and to c) (c) it increases the uptake of m and suffer from triglycerides from the blood energy into adipose tissue and utilization muscle, ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written  Bone Cells 4. Osteoclasts—bone-dissolving cells found on bone surface – Osteoclasts develop from stem cells that give rise to blood cells (different origin from other bone cells) – Very large cells that have multiple nuclei in each cell – Ruffled border (large surface area) faces bone – Dissolving bone is part of bone remodeling Please read and study the word document in Unit 3 Module Chapter 7 entitled “Osteoclasts and Osteoblasts” Professor DaveWatch the Video Explains: Bones Structure and Type https://www.youtube.com/watch?v=2vESq p8mL5I ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written  The Matrix Matrix of osseous tissue is, by dry weight, about one-third organic and two-thirds inorganic matter (composite material plus protein derivatives. 33% Organic matter— Ceramic Portion of Bone synthesized by Calcium and Phosphate osteoblasts salts are the ceramic Collagen, Ceramic portion carbohydrate–protein allows the bone to complexes, such as support body weight glycosaminoglycans, without sagging proteoglycans, and glycoproteins Polymer Portion of Bone 66% Inorganic matter Collagen is the polymer Polymer (protein) 85% calcium gives some flexibility phosphate ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written  The Matrix Bone is a composite material Ceramic Portion of Bone – Calcium and Phosphate salts are the ceramic – Ceramic portion allows the bone to support body weight without sagging Polymer Portion of Bone – Collagen is the polymer – Polymer (protein) gives some flexibility ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written The Marrow Cavity – Bone Marrow ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written The Marrow Cavity – Bone Marrow Site of Hematopoiesis Myeloid Lineage: Lymphoid Lineage: Erythropoiesis, Hemopoiesis, Lymphopoiesis Thrombopoiesis Leukopoiesis Red Yellow Marrow Marro w ©McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written