Newest Assignments and Dates (If assignment is online it shall be stated below)

  • 03-17-2008 - 03-21-2008 -Spring Break (FREEDOM)
  • 03-21-2008 -Art History Outline and images
  • Still during spring break: Read Lord of the Flies for techniques/devices, 3 allusions due.

Saturday, October 20, 2007

Physiology -Chap 6- Outline

The Skeletal System: Bone Tissue

Functions of Bone and The Skeletal System

  • The functions of the skeletal system
    • Support: Framework for the body, supports soft tissues and provides attachment point for tendons of most skeletal muscles
    • Protection: Protect most important internal organs from injury
    • Assistance in Movement: Attach to bones; when the contract, they pull on bones to produce movement
    • Mineral Homeostasis: Bone tissue stores several minerals (calcium & phospherus)
    • Blood Cell Production: CT called red bone marrow produces more RBC, WBC, and platelets (called hemopoisis
    • Triglyceride Storage: Yellow bone marrow consists of adipose cells which store Trigly. The stored Trygly. Are a potential chemical energy reserve

    Structure of the Bone

  • Lone bone=Greater length than width
  • Long bone consists of:
    • Diaphysis
    • Epiphyses
    • Metaphyses
    • Epiphyseal Plate
    • Articular Cartalidge
    • Periosteum
    • Medullary Caivity

    Histology of Bone Tissue

  • Bone tissue contains EC-M
    • 25% water, 25% Collagen fibers, 50% crystallized mineral salts.
      • Calcium phosphate + calcium hydroxide = hydroxyapatite
        • Califacation started by bone building cells
          • Process requires presences of collagen fibers
  • Hardness = crystallized minerals
  • Flexibility = collagen fibers
    • Provide tensile, strength, and resistance
  • Four cells in tissue:
    • Osteogenic Cells: Unspecialized stem cells derived from mesenchyme, the tissue from which all CT are made from
    • Osteoblasts: Bone building cells. Synthesizes and secrete collagen
    • Osteocytes: Mature bone cells are the main cells in bone tissueand maintain it's daily metabolism
    • Osteoclasts: Cells derived from fusion of as many as 50 monocytes and are concentrated in the endosteum

    Compact Bone Tissue

  • Compact bone tissue contains few spaces
  • Strongest form of BT
  • Found beneath periosteum, makes up bulk of long bones
  • Blood vessels, lymthpatic vessels, ect. Transverse perforating canals
  • Central canals
    • Around those are the concentric lamellae
    • Between lamellae are the lacunae
      • Tiny canaliculi filled with EC fluid
  • Components of compact bone tissue are arranged into repeating units calls osteons or haversian systems
    • Parallel in shaft
      • Does not bend or fracture
      • Lines of stress change as baby starts to walk
  • Area between osteans contain interstitial lamellae

    Spongy Bone Tissue

  • No osteons
  • Refers to appearance
  • Consists of lamellae arranged in lattice of thin columns called trabeculae
    • Lacunae contain osteocytes
  • Spongy bone tissue make up most of bone tissue of short flat, and irregularly shaped bones


    Diaphysis:Shaft of bone; long cylindrical main portion

    Epiphyses: Distal and proximal ends of bone

    Metaphyses: Regions in mature bone where the diaphysis join the epiphyses. Each meta. Includes an

    Epiphyseal Plate: Layer of hyaline cartilage that allows diaphylsis of bone in great length

    Epiphyseal Line: The boney result of the cartilage in the epip. plate being replaced by bone, caused by the stop of growth of the bone

    Articular Cartalidge Thin layer of hyaline cartilage covering epip. where the bone forms a joint with another bone

    Periosteum: Tough sheath of dense irregular CT that surrounds the done surface, enable bones to grow in thickness, not length. Aids in healing of bone

    Medullary Caivity: space within the diaphysis that contains fatty yellow bone marrow in adults

    Endosteum: Thin membrane that lines the medullary cavity. Contain single layer of bone forming cells and a small amount of CT

    Bone/Osseous Tissue: CT, contains abundant EC-M

    Hydroxyapatite: Calcium phosphate + calcium hydroxide

    Process of minerals combining to form other minerals

epiphyseal plate

No comments: