Bone Function and Structure

 Histology of Bone Tissue  Bone Function and Structure  Bone Growth & Development  Joints  The Axial Skeleton  The Pectoral Girdle  The Upper Limbs  The Pelvic Girdle  The Lower Limbs

 FUNCTIONS  Support- framework that supports body and cradles its soft organs  Protection- for delicate organs, heart, lungs, brain  Movement- bones act as levers for muscles  Mineral storage- calcium & phosphate  Blood cell formation- hematopoiesis

 Bones classified by shape:  Long - metacarpals, metatarsals, phalanges, humerus, ulna, radius, tibia, fibula  Short - carpals, tarsals  Flat - rib, scapula, skull, sternum  Irregular - vertebrae, some facial bones  Round (Sesamoid) - patella

LONG BONE STRUCTURE  Diaphysis- middle  compact bone  medullary cavity- contains yellow marrow (fat)  lined with endosteum (squamous epithelium  Metaphysis: regions between diaphysis and epiphysis  Epiphyseal growth plate: layer of hyaline cartilage that allow diaphysis to grow in length; ceases to grow between ages 18-21; replaced by bone then becomes epiphyseal line  Epiphysis- ends  spongy bone contains red marrow  compact bone, articular cartilage

LONG BONE STRUCTURE (CONT.)  Articular cartilage: thin layer of hyaline cartilage where bone articulates (joint) with another; reduces friction and absorbs shock  Bone enclosed in periosteum, composed of outer fibrous layer of dense irregular connective tissue and inner osteogenic layer; allows bone growth in thickness; protects bone, assists in fracture repair, bone nourishment and attachment point for ligaments and tendons  Perforating fibers: Sharpey’s fibers, attachment to underlying bone, c/o thick bundles of collagen extend into extracellular matrix of bone  Blood vessels in periosteum  Medullary cavity: hollow cylindrical space with diaphysis that contains fatty yellow marrow in adults  Endosteum: thin membrane that lines the internal surface facing the medullary cavity; made of single layers of cells and connective tissue

Copyright 2009, John Wiley & Sons, Inc.  Bone supplied with blood  Periosteal arteries: with nerves supply periosteum and compact bone  Epiphyseal veins: carry blood away from long bones  Nerves accompany blood vessels that supply bones  Periosteum has many sensory nerves sensitive to tearing or tension

 Histology of Bone Tissue  Bone Function and Structure  Bone Growth & Development  Joints  The Axial Skeleton  The Pectoral Girdle  The Upper Limbs  The Pelvic Girdle  The Lower Limbs