Skip to main content
Back

Anatomy & Physiology: Skeletal System and Bone Structure

Control buttons has been changed to "navigation" mode.
1/20
  • Functions of bones
    Support, protection, assistance in movement, blood cell production, storage of minerals and triglycerides, and mineral homeostasis.
  • Difference between red and yellow bone marrow
    Red bone marrow is the site of hemopoiesis producing RBCs, WBCs, and platelets. Yellow bone marrow stores triglycerides.
  • Composition of bone matrix
    Bone matrix is about 50% \(Ca_3(PO_4)_2\), 25% water, and 25% collagen fibers which provide flexibility and mineral support.
  • Four classifications of bones by shape
    Long bones (longer than wide), short bones (length and width about equal), flat bones (broad and flat), and sesamoid bones (round bones embedded in tendons).
  • Anatomy of a long bone
    Includes diaphysis (shaft), epiphysis (ends), medullary cavity (marrow cavity), metaphysis (between diaphysis and epiphysis), and epiphyseal plate (growth plate).
  • Periosteum and endosteum
    Periosteum is the dense irregular connective tissue covering the outer bone surface; endosteum lines the inner surface adjacent to the medullary cavity.
  • Bone cell types and functions
    Osteogenic cells are immature stem cells; osteoblasts build bone matrix; osteocytes maintain bone; osteoclasts resorb bone releasing calcium.
  • Compact vs spongy bone structure
    Compact bone is dense and forms the outer layer; spongy bone is porous, found inside bones, and contains red bone marrow.
  • Cartilage cell types
    Chondroblasts produce cartilage matrix; chondrocytes maintain cartilage and reside in lacunae.
  • Cartilage growth types
    Interstitial growth increases length by chondrocyte mitosis inside cartilage; appositional growth increases width by stem cells in perichondrium producing new cartilage.
  • Initial bone formation process
    Bone forms by replacing cartilage or connective tissue through ossification involving osteoblasts depositing bone matrix.
  • Bone growth at epiphyseal plate
    Cartilage grows, calcifies, is resorbed by osteoclasts, and replaced by bone from osteoblasts, allowing lengthening of long bones.
  • Bone remodeling
    Bone is continuously reshaped by balanced activity of osteoblasts (bone formation) and osteoclasts (bone resorption) to maintain strength and calcium levels.
  • Common bone disorders
    Osteoporosis is weak, porous bones due to excessive resorption; osteomalacia is soft, flexible bones due to poor mineralization.
  • Stages of fracture repair
    1) Hematoma formation, 2) Fibrocartilaginous callus formation, 3) Bony callus formation, 4) Bone remodeling.
  • Axial vs appendicular skeleton
    Axial skeleton includes skull, vertebral column, and thoracic cage; appendicular skeleton includes limbs and girdles.
  • Bone markings and their functions
    Projections for muscle/tendon attachment, smooth areas for articulation, and depressions/grooves for blood vessels and nerves.
  • Sutures in the skull
    Immovable joints between cranial bones connected by dense regular connective tissue with interlocking edges.
  • Role of osteocytes in bone
    Osteocytes maintain bone matrix and communicate with other bone cells through canaliculi to regulate bone health.
  • Calcium resorption in bone
    Process where osteoclasts break down bone matrix releasing calcium into the bloodstream.