Chapter 6 Powerpoint for Martini Essentials of A&P

Chapter 6 Osseous Tissue and Skeletal Structure Learning Objectives Describe the functions of the skeletal system. Classify bones and identify the major markings. Identify cell types in bone and list their functions. Compare spongy and compact bone. Compare intramembranous and endochondral ossification. Discuss the effects of nutrition, hormones, exercise and aging on the bones. Describe the types of fractures. Bones of the skeleton Cartilages, ligaments and other connective tissues that stabilize and connect The skeletal system includes The skeletal system includes Functions of the skeletal system Support Storage of minerals and lipids Blood cell production Protection Leverage Long Flat Short Irregular Sesamoid Sutural A Classification of Bones Bone shapes Classification of Bones by Shape Compact bone (dense) Spongy bone (cancellous) Bone structure = two types of bone Supporting tissue with a solid matrix Crystals of hydroxyapatite Minerals deposited in lamellae Covered by periosteum Bone Histology Osseous tissue Osteocytes = mature bone cells In lacunae Connected by canaliculi Osteoblasts synthesize new matrix Osteogenesis Osteoclasts dissolve bone matrix Osteolysis Osteoprogenitor cells differentiate into osteoblasts Cells in bone: The Histology of Compact Bone The Histology of Compact Bone Basic unit of compact bone is an osteon Osteocytes arranged around a central canal Perforating canals extend between adjacent osteons Spongy bone contains trabeculae Compact bone and spongy bone The Structure of Osseus Tissue Compact bone located where stresses are limited in direction Spongy bone located where stresses are weaker or multi-directional Bones and stress The Distribution of Forces on a Long Bone Covered by periosteum Lined by endosteum Bones are: Ossification = converting other tissue to bone Calcification = depositing calcium salts within tissues Bone development and growth Begins with osteoblast differentiation Dermal bones produced Begins at ossification center Intramembranous ossification Intramembranous Ossification Cartilage model gradually replaced by bone at metaphysis Increasing bone length Timing of epiphyseal closure differs Appositional growth increases bone diameter Endochondral ossification Endochondral Ossification Endochondral Ossification Animation: Endochondral Ossification (Check animations) Bone Growth at an Epiphyseal Cartilage Appositional Bone Growth Appositional Bone Growth The Circulatory Supply to a Mature Bone Remodeling Exercise Hormone levels Growth hormone and thyroxine increase bone mass Calcitonin and PTH control blood calcium levels The Dynamic Nature of Bone Continually changing A Chemical Analysis of Bone 99% body’s calcium in the skeleton Calcium ion concentration maintained by bones GI tract and kidneys Calcitonin and PTH regulate blood calcium levels Calcitonin decreases blood calcium levels PTH increases blood calcium levels The skeleton is a calcium reserve Factors that Alter the Concentration of Calcium Ions in Body Fluids Factors that Alter the Concentration of Calcium Ions in Body Fluids Fracture hematoma External callus Internal callus Fracture repair Steps in the Repair of a Fracture Are characteristic for each bone and each individual Markings include Elevations Projections Depressions Grooves and tunnels Bone Markings (Surface Features) Bone markings Osteopenia Osteoporosis Aging and the Skeletal System Effects of aging include The Effects of Osteoporosis You should now be familiar with: The functions of the skeletal system. Bones and their major markings. Cell types in bone and their functions. Spongy and compact bone. Intramembranous and endochondral ossification. The effects of nutrition, hormones, exercise and aging on the bones. The types of fractures.