Chapter 6: Skeletal System

Cards (69)

  • Components of Skeletal System
    Bones
    Cartilages
    Tendons
    Ligaments
  • Functions of Skeletal System
    1.Body support
    2. Organ protect
    3. Body movement
    4. Mineral storage
    5. Blood cell production
  • Bone, cartilage, tendons, and ligaments of the skeletal system are all connective tissues.
  • The matrix always contains collagen, ground substance, and other organic molecules, as well as water and minerals.
  • Collagen
    is a fibrous protein that provides flexibility but resists pulling or compression.
  • Matrix ground substance contains proteoglycans which are water trapping proteins that help cartilage to be smooth and resilient.
  • Bone Matrix
    is about 35% organic and 65% inorganic material by weight. The organic material is primarily collagen and proteoglycans.
  • hydroxyapatite
    the inorganic material in bone matrix
  • Collagen fibers lend flexible strength to the bone
  • The mineral component gives bone compression (weight bearing) strength.
  • Osteoblasts
    are responsible for the formation of bone and the repair and remodeling of bone.
  • What do osteoblasts produce?
    collagen and proteoglycans
  • Ossification
    formation of new bone by osteoblasts
  • Osteocytes
    are cells that maintain bone matrix and form from osteoblast after bone matrix has surrounded it.
  • Osteocytes account for 90–95% of bone cells and are very long-lived
  • Lacunae
    Osteocyte cell bodies are housed within the bone matrix
  • Canaliculi
    Their cell extensions are housed in narrow, long spaces
  • Osteoclasts
    bone-destroying cells
  • Reabsorption (Osteoclasts)

    contribute to bone repair and remodeling by removing existing bone
  • Bone breakdown is important for mobilizing crucial Ca2+. As bone is broken down, the Ca2+ goes into the blood.
  • Lamellar Bone
    Mature bone
  • Lamellae
    organized lamellar bone into thin, concentric sheets or layers
  • Spongy bone consists of interconnecting rods or plates of bone called trabeculae
  • Spaces in trabeculae are filled with bone marrow and blood vessels
  • Compact bone

    cortical bone, is the solid, outer layer surrounding each bone
  • The functional unit of compact bone is an osteon. It is composed of concentric rings of matrix surrounding a central canal
  • Canaliculi
    connect osteocytes to one another, transport nutrients and remove waste
  • Lamellae
    are concentric rings of bone matrix which surround the central canal
  • Diaphysis
    the center portion of the bone
  • Medullary cavity
    hollow center of the long bone
  • Epiphyses
    contain mostly spongy bone, with an outer layer of compact bone; ends of a long bone
  • Articular cartilage
    end of a long bone is covered with hyaline cartilage
  • Epiphyseal plate is located between the epiphysis and the diaphysis. Growth in bone length occurs at the epiphyseal plate.
  • Epiphyseal line
    When bone stops growing in length, the epiphyseal plate becomes ossified
  • Bone Marrow
    Cavities in spongy bone and the medullary cavity in the diaphysis are filled with soft tissue
  • Red Marrow
    is the location of blood forming cells
  • Yellow marrow is mostly fat
  • The outer surface of a bone is covered by a connective tissue membrane called periosteum
  • The endosteum is a single cell layer of connective tissue that lines the internal surfaces of all cavities within bones; includes osteoblasts and osteoclasts
  • Intramembranous ossification
    starts within embryonic connective tissue membranes; occurs when osteoblasts begin to produce bone within connective tissue; occurs primarily in the bones of the skull;