Skeletal System

Cards (104)

  • Functions of Skeletal System:
    • Support
    • Protect
    • Movement
    • Storage
    • Blood cell production
  • Components of Skeletal System:
    • Bone
    • Cartilage
    • Tendons
    • Ligaments
  • Components of Skeletal System
    Cartilage - reduce friction and model for bone formation
  • Components of Skeletal System
    Tendons - attach bone to muscle
  • Components of Skeletal System
    Ligaments - attach bone to bone
  • Proteoglycans - large polysaccharides attached to proteins that is a part of ground substance and stores water
  • Bone’s extracellular matrix is collagen and minerals (flexible and able to bear weight)
  • Cartilage’s extracellular matrix is collagen and proteoglycans (good shock absorber)
  • Tendons and ligaments’ extracellular matrix is collagen (very tough)
  • Classification of Bones
    Based on shape:
    • Long
    • Short
    • Flat
    • Irregular
  • Classification of Bones
    Type of bone tissue:
    • compact
    • spongy (cancellous)
  • Long Bone Structures
    • Diaphysis
    • Epiphysis
    • Articular cartilage
    • Epiphyseal plate
    • Medullar cavity
    • Periosteum
    • Endosteum
  • Long Bone Structures
    Diaphysis:
    • shaft
    • compact bone tissue (on outside)
  • Long Bone Structures
    Epiphysis:
    • ends
    • spongy bone tissue
  • Long Bone Structures
    Articular cartilage:
    • covers epiphyses
    • reduces friction
  • Long Bone Structures
    Epiphyseal plate:
    • site of growth
    • between diaphysis and epiphysis
  • Long Bone Structures

    Medullary cavity:
    • center of diaphysis
    • red or yellow marrow
  • Long Bone Structures
    Periosteum:
    • membrane around bone’s outer surface
  • Long Bone Structures
    Endosteum:
    • membrane that lines medullary cavity
  • Compact Bone Tissue - outer part of diaphysis (long bones) and thinner surfaces of other bones
  • Parts of Compact Bone Tissue
    • Osteon
    • Lamella
    • Lacunae
    • Canaliculus
    • Central canal
  • Compact Bone Tissue
    Osteon:
    • structural unit of compact bone
    • includes lamella, lacunae, canaliculus, central canal, osteocytes
  • Compact Bone Tissue
    Lamella:
    • rings of bone matrix
  • Compact Bone Tissue
    Lacunae:
    • spaces between lamella
  • Compact Bone Tissue
    Canaliculus:
    • tiny canals
    • transport nutrients and remove waste
  • Compact Bone Tissue
    Central canal:
    • center of osteon
    • contains blood vessels
  • Spongy Bone Tissue - also known as "cancellous bone" and is located in the epiphyses of long bones and center of other bones; no osteons.
  • Trabeculae - interconnecting rods, spaces contain marrow
  • Bone Cells
    • Osteocytes
    • Osteoblasts
    • Osteoclasts
  • Bone Cells
    Osteocytes - maintain bone matrix
  • Bone Cells
    Osteoblasts - build bone
  • Bone Cells
    Osteoclasts - carve bone
  • Bone Formation
    Ossification - process of bone formation (occurs in utero)
  • Bone Formation
    Osteoblast’s role:
    • build bone
    • after an osteoblast becomes surrounded by bone matrix it becomes an osteocyte
  • Bone Formation
    Ossification center - where bone formation begins
  • Bone Formation
    Primary ossification center:
    • where bone 1st begins to appear
    • forms diaphyses
  • Bone Formation
    Secondary ossification center - forms epiphyses
  • Intramembranous Ossification - bone formation within connective tissue membranes where osteoblast build bone (Ex. Skull bones)
  • Endochondral Ossification - bone formation inside cartilage where cartilage models are replaced by bone (All bones, except skull)
  • Steps in Endochondral Ossification
    1. Chondroblasts build a cartilage model, the chrondroblasts become chondrocytes.
    2. Cartilage model calcifies (hardens).
    3. Osteoblasts invade calcified cartilage and a primary ossification center forms diaphysis.
    4. Secondary ossification centers form epiphysis.
    5. Original cartilage model is almost completely ossified and remaining cartilage is articular cartilage.