Chapter 7 Skeletal Tissues Slide

Introduction Description of bone Functions of bone Active living Tissue Organ Functions of bone Muscle attachment Protection Support Blood cell production Mineral storage Slide

Types of Bones - varied structure to meet varied needs Four Types Long bones Short bones Flat bones Irregular bones Slide

Types of Bone Tissue Compact bone Cancellous bone (Spongy Bone) Slide

Parts of a long bone Diaphysis Epiphyses Articular Cartilage Periosteum Medullary cavity Endosteum Slide

Short, flat and irregular bones Inner portion - Cancellous bone Outer portion - compact bone Some with bone marrow Slide

Bone Tissue Characteristics Connective tissue Great Tensile strength Composition of bone matrix Inorganic salts Crystals of calcium and phosphate Magnesium and sodium ground substance Slide

Dancing skeleton Puppet Slide

Bare bones Slide

Microscopic Structure of the Bone (Figure 7-3) Compact bone Osteons, or Haversian systems Canals connecting cells and osteons- Canaliculi and Volkmann’s Osteocytes Purpose Slide

The structure of bone Slide

Microscopic Structure of the Bone Compact bone Four types of structures make up each osteon: Lamella Lacunae Canaliculi Haversian canal (central canal) Slide

Microscopic Structure of the Bone Cancellous bones (spongy) No osteons Trabeculae - support marrow Nutrients and waste transported by diffusion Slide

Types of bone cells Osteocytes Osteoblasts Osteoclasts Slide

The life of an osteoclast Slide

Bone Marrow Made of myeloid tissue Red marrow - produce of blood cells Located in medullary cavities of long bones and in the spaces of spongy bone Two types of marrow Red marrow Yellow marrow Slide

Regulation of Blood Calcium Levels Cells that maintain constancy of blood calcium levels Osteoblasts -take calcium from blood to build bone Osteoclasts - remove calcium from bone Homeostasis essential Bone formation, remodeling, and repair Blood clotting nerve impulses Muscle contraction Slide

Mechanisms of calcium homeostasis Parathyroid hormone - primary calcium regulator Stimulates osteoclasts to break down bone Increase renal absorption Stimulates vitamin D synthesis Calcitonin - produced in thyroid Stimulates bone deposit by osteoblasts Inhibits osteoclasts Slide

Development of Bone Osteogenesis Intramembranous ossification (flat bones) Osteoblasts formed Osteoblasts secrete matrix and collagen Calcium is deposited Trabeculae form Endochondral ossification (long bones) - begin as cartilage Diaphysis ossifies before epiphysis Epiphyseal plate - growth plate Layers Resting cartilage Zone of proliferation, Zone of hypertrophy Zone of calcification Slide

Fractures Fracture - damages tissues and blood vessels Vascular damage initiates repair Fracture healing Slide

steps Callus forms - specialized repair tissue - binds broken ends together Fracture hematoma - blood clot - occurs after fracture, then resorbed and replaced by callus Slide

Compression fracture Slide

Depression fracture Slide

Impacted fracture Slide

Spiral fracture Slide

Greenstick Fracture Slide

Simple fracture Slide

Compound fracture Slide

Dislocation Slide

Cartilage Characteristics Avascular Fibers embedded in gel Flexibility of firm plastic Chondrocytes - nutrients, oxygen by diffusion Perichondrium- covering Slide

Cartilage - differ because of amount of matrix and fibers Types of cartilage Hyaline cartilage - most common Articular surfaces, found in trachea, bronchi, tip of nose Elastic cartilage - external ear, epiglottis, eustachian tubes Fibrocartilage - occurs in symphysis pubis, intervertebral discs Slide

Cartilage Histophysiology of cartilage - permits cartilage to sustain great weight/serve as shock absorber Growth of cartilage Interstitial or endogenous growth - cartilage cels divide/secrete matrix - during childhood/adolescense Slide

Cycle of Life: Skeletal Tissues Ossified by mid-twenties Adults—changes occur from specific conditions Increased density and strength from exercise Decreased density and strength from pregnancy, nutritional deficiencies, and illness Advanced adulthood—apparent degeneration Hard bone matrix replaced by softer connective tissue Exercise can counteract degeneration Slide

Skeletal movement Slide