The Skeletal System Chapter 7a Skeletal System Introduction Functions of the skeleton Framework of bones The skeleton through life Functions of the Skeleton Support Protection Movement Storage areas Minerals Lipids Hemopoiesis Red marrow Histology of Bones Bone = osseous tissue (connective tissue) Intercellular substance Calcium phosphate crystals Collagenous fibers Human Anatomy, 3rd edition Prentice Hall, 2001 Anatomy of a Long Bone Diaphysis shaft Epiphysis extremity of bone Articular cartilage covers epiphysis Periosteum covering around surface of bone Medullary cavity marrow cavity in diaphysis Endosteum lines medullary cavity Human Anatomy, 3rd edition Prentice Hall, 2001 The Periosteum Two layers Outer layer Fibrous connective tissue Inner layer Osteoblasts Human Anatomy, 3rd edition Prentice Hall, 2001 The Endosteum Single layer Osteoclasts Osteoblasts Human Anatomy, 3rd edition Prentice Hall, 2001 Structure of Bone Tissue Pores Living cells Channels for blood vessels Decrease weight of bone Degree of porosity Spongy bone Compact bone Human Anatomy, 3rd edition Prentice Hall, 2001 Compact Bone Haversian system (Osteon) Haversian canals Lacunae Canaliculi Human Anatomy, 3rd edition Prentice Hall, 2001 Spongy Bone Composed of trabeculae Penetrated by blood vessels from periosteum Ossification Embryo skeleton Begins as cartilage & membrane Bone formation begins about 6 weeks after fertilization Ossification 1 st stage embryonic cells migrate into future bone sites Become chondroblasts or Become osteoblasts Endochondral Ossification Occurs within a hyaline cartilage model Occurs in most bones of the body Periosteum forms at about week 8 Calcification begins in center of diaphysis Primary ossification center Secondary ossification centers at epiphyses Medullary cavity forms Endochondral Ossification Fetus. 10 weeks Fetus, 16 weeks Remaining Cartilage Articular cartilage Epiphyseal plate Bone grows in length Homeostasis Remodeling Different rates in body Balance between osteoclasts and osteoblasts Factors affecting bone growth Calcium & phosphorus in diet Vitamins A, C, & D Hormones Fracture Repair Hematoma formation Formation of fibrocartilagenous callus Formation of bony callus Remodeling of bony callus Fracture Repair Disorders Vitamin deficiencies Scurvy Rickets Osteoporosis Scurvy Scurvy Blood Vessels Rickets Osteoporosis Human Anatomy, 3rd edition Prentice Hall, 2001 Organization of the Skeletal System Axial skeleton Skull Vertebral column Thoracic cage Appendicular skeleton Pectoral girdle Upper limbs Pelvic girdle Lower limbs Human Anatomy, 3rd edition Prentice Hall, 2001 The Human Skeleton Human Anatomy, 3rd edition Prentice Hall, 2001 Skull Cranium Protects brain Facial bones Protect sense organs Human Anatomy, 3rd edition Prentice Hall, 2001 Vertebral Column Vertebrae Cervical Thoracic Lumbar Sacral Sacrum Coccyx Function Protect spinal cord and nerves Human Anatomy, 3rd edition Prentice Hall, 2001 Intervertebral Discs Vertebrae Separated by intervertebral discs Human Anatomy, 3rd edition Prentice Hall, 2001 The Atlas and Axis Human Anatomy, 3rd edition Prentice Hall, 2001 A Typical Vertebra Human Anatomy, 3rd edition Prentice Hall, 2001 The Sacrum and Coccyx Sacrum Several fused vertebrae Coccyx Rudimentary tailbone Human Anatomy, 3rd edition Prentice Hall, 2001 Thoracic Cage Ribs (12 pairs) Articulate with vertebrae Sternum (breastbone) Function Protect underlying organs Human Anatomy, 3rd edition Prentice Hall, 2001 Pectoral Girdle Scapula (shoulder blade) Clavicle (collar bone) Attached to posterior ribs and sternum Function Connects bones of arms to axial skeleton Aids in arm movements Human Anatomy, 3rd edition Prentice Hall, 2001 Upper Limbs Humerus Radius Ulna Carpals Metacarpals Phalanges Human Anatomy, 3rd edition Prentice Hall, 2001 The Radius and Ulna Human Anatomy, 3rd edition Prentice Hall, 2001 Bones of the Wrist and Hand Human Anatomy, 3rd edition Prentice Hall, 2001 Pelvic Girdle Coxal (hip) bones Ileum Ischium Pubis Attached to sacrum and coccyx Function Connect bones of legs to axial skeleton Human Anatomy, 3rd edition Prentice Hall, 2001 The Pelvic Girdle Human Anatomy, 3rd edition Prentice Hall, 2001 Lower Limbs Femur Tibia Fibula Patella Tarsals Metatarsals Phalanges Human Anatomy, 3rd edition Prentice Hall, 2001 The Femur Human Anatomy, 3rd edition Prentice Hall, 2001 Bones of the Lower Leg Human Anatomy, 3rd edition Prentice Hall, 2001 The Patella Human Anatomy, 3rd edition Prentice Hall, 2001 Bones of the Foot