Ch 5 Skeletal System 26 01 2010 19 14 00 Go to medical school library in learning resource center and look at the bones in the boxes Sunday afternoon 3rd floor from 1 3 to review Practice exam goes up sunday Function of the Skeleton Support o Structural support o Attachment of muscles o Weight and work with work with muscles to produce control Storage of mineral o Maintains normal concentration in the body fluids o Calcium 98 o Phophastes Blood Cell production o In red bone marrow Protection o Skull and rib cage Leverage Bone as Tissue Dense connective tissue Cells o Osteoblasts develops into an osteocyte Immature bone forming cells Synthesize osteoid organiz components of matrix calcifies to form hard matrix Produces now bone osteogenesis o Osteoclasts Large multi nucleated cells Dissolves bony matirs osteolysis Regulate Ca2 and phosphate concentrations o Osteoprogenitor cells Mesenchymal embryonic stem cells Produces osetoblasts Play a role in fracture repair Larger than osteoblast and not always seen o Osteocytes is the cell of the bone Mature bone cells Completely surrounded by hard bone matrix Maintain and monitor both protein and mineral content of matrix Found in lacunae Interconnected by canaliculi layers of matrix lamellae o Osteoblast vs osteoclasts Blast secrete bony matrix to make bone strong Clast dissolves the bony matrix which releases ca2 into the body fluids Keeps the bone strong and in balance Blast deposit Ca2 faster than the clasts removes them stronger and larger bones Clasts remove ca2 faster than blast weak brittle bone Matrix o Collagen fibers 1 3 weight of the bone tough and flexible o Surrounded by calcium salts o Calcium phosphate joins with calcium hydroxide 2 3 of the weight of the bone o Osteocytes make up 2 Types of bones Compact Dense and solid on outside all around o Collagen fibers switches each layer giving more strength to resist cracking o Osteon is the basic functional unit looks like a bulls eye o Osteocytes arranged in concetric layers around central canal which contain vessels need vessels to supply blood otherwise bone dies Perforating canals connect central canals o Lamellae Cylindrical and parallel to long axis of bone Concentric lamellae the bulls eye Interstitial lamellae in between concentric lamellae Circumferential lamellae on outer surface and inner surface of the bone Spongy cancellous bone Forms an open network on inside o Trabeculae Arranged in plates or struts o No osteons Long Bone humerus or femur Diaphysis shaft o Only one Epiphysis ends of the bone o Two at each end Metaphysis between diaphysis and epipysis o Two of them Covers of the bone Periosteum covers the bone o Cellular layer inner layer that holds bone production o Fibrous layer outer layer o Isolates and protects bone o Highly vascular and contains numerous nerves where pain comes from Ends of the tendon and the periosteum bind together to give great strength so the bone will break before the muscle gets pulled off the bone Layers lining marrow cavity Endosteum o Incomplete cellular layer o Usually one cell thick o Contains osteoprogenitor cells Terms Osteogenesis production of new bone Osteolysis break down of bone Calcification deposition of calcium salts in tissue Ossification replacing EXISITING tissue with bone o Intramembranous Includes flat bone of the skull and the mandible and some ear bones Develops from the mesenchyme embryonic CT CT develops straight into bone Osteoprogenitor cells osteoblast osteocytes Osteoblasts secrete matrix Mineralization of calcium salts take place Step 1 mesenchymal cells develop into osteoblasts Step 2 KNOW ALL STEPS o Endochondral Mensenchyme hyaline cartilage bone Chrondocytes enlarge in center of bone Chondrocytes osteoblasts Perochrondrium periosteuminner cellular layer is osteogenetic layer bone collar produces osteoblasts osteoblast migrate to center primary ossification center bone sent down in the center ossification centers where ossification begins involved in both forms of ossification primary in diaphysis only 1 o cartilage breaks down replaced by spongy bone until the metaphysis o cavity formed by osteoclasts to form marrow cavity o growth is length of the bone metaphysis secondary ossification center in epiphysis 2 at each end o center of epiphysis is bone o chrondrocytes osteocytes width of bone is appositional growth in periosteum growth is lengthening of the bone at 2nd ossification center piphyseal cartilage plate growth plate o can tell age of a child by size of epiphyseal plate or ossification process diaphysis side bone epipihysis side cartilage go over this shit im still confused damn facebook Fracture Repair of Bone Hematoma occurs Osteoprogentior form cartilage bump Osteoclasts take away debris Bone ends up stronger and thicker where the break was Classification of bones Long o Longer bones femur humerus phalanges o 1 dia and 2 epip Flat o Skull o Compact bone makes bread of a sandwich o Spongy bone makes the bologna Pneumatized o Has air in it somewhow o Has a sinus Irregular o vertabrae Short o Carpal and tarsal bones Seasmoid o Develops in a tendon o Patella in the tendons of the quadriceps Bone Markings Trochanter large rough projection Head Neck COMMON BONE MARKING TERMINOLOGY know these TABLE 5 1 Tuberocity smaller rough projection Spine pointed process Learn specific names if told Axial Skeleton in the straight line skull o cranial bones 8 bones intramembranous ossification 1 frontal forehead 1 pariteal on the side 1 occipital in the back 2 temporal 1 sphenoid 1 ethnoid immovable joints sutures 5 of them know them Fetal skulls have cartilage where sutures will be close at age 2 o facial bones 14 bones maxillary 1 located in face oral cavity nasal cavity orbit what angles can you see it palatine 2 nasal 2 2 zygotmatic 2 lacrimal 2 inferior concha 1 mandible Appendicular Skeleton The limbs 26 01 2010 19 14 00 26 01 2010 19 14 00