Bone Tissue

  1. How many bones are in an adult human skeleton?
  2. Osteology
    the study of bone
  3. What is the Skeletal System made of?
    composed of bone, cartilage, and ligaments
  4. Ligaments
    hold bone to bone at joints
  5. Tendons
    attach muscle to bone
  6. Functions of the Skeleton
    • Support
    • Protection
    • Movement
    • Electrolyte balance
    • pH balance
    • Blood formation
  7. Bone (Osseous tissue)
    • connective tissue with matrix hardened by calcium
    • Called Mineralization or Calcification
  8. Flat Bones
    • Curved but wide and thin
    • Example: Ribs
    • Function: protect soft organs
  9. Long Bones
    • Longer than wide
    • Functions: Rigid levers acted upon by muscles
    • Example: Femur
  10. Short Bones
    • Equal in length and width
    • Function: glide across one another in multiple directions
    • Example: carpal bones
  11. Irregular Bones
    • Elaborate shapes that don't fit into other categories
    • Example: vertabrae
  12. Epiphyses
    Enlarged heads of long bones
  13. Compact Bone
    • Also Dense Bone
    • Outer shell of bones
  14. Diaphysis
    • shaft of long bones
    • cylinder of compact bone to provide leverage
  15. Spongy Bone
    • also Cancellous Bone
    • always covered by compact bone
    • lighter and less dense than compact bone
  16. Articular Cartilage
    layer of hyaline cartilage that covers joint surfaces
  17. Nutrient Foramina
    Minute holes in the bone surface to allow blood vessels to penetrate
  18. Periosteum
    • external sheath that covers bone except where the articular cartilage is
    • made of dense irregular CT
    • Outer fibrous layer of collagen
    • perforating fibers for strong attachment
  19. Endosteum
    Thin layer of reticular CT lining marrow cavity
  20. Epiphyseal Place
    • Line of hyaline cartilage that separates marrow space of the epiphysis and diaphysis
    • Only seen in children who are still growing
  21. Dipole
    • Flat bone composition
    • Spongy layer sandwiched in between two layers of compact bone
    • Absorbs shock
  22. Osteogenic Cells
    • Stem Cells found in periosteum, endosteum and central canals
    • arise from mesenchym
    • produce new osteoblasts
  23. Osteoblasts
    • Synthesis soft organic matter matrix which hardens through calcification
    • nonmitotic
  24. Osteocytes
    • Former osteoblasts that have become trapped in matrix
    • Maintain bone matrix
  25. Lacunae
    Little cavities in bone matrix where osteocytes live
  26. Canaliculi
    Little channels that connect lacunae
  27. Cytoplasmic Processes
    part of the osteocyte that reach into the canaliculi
  28. Osteoclasts
    • Bone-dissolving cell found on the bone surface
    • Not a bone cell
  29. Remodeling
    results from combined action of the bone-dissolving osteoclasts and the bone-depositing osteoblasts
  30. Matrix Composition
    • 1/3 organic matter deposited by cells by weight
    • 2/3 inorganic matter
    • -85% hydroxyapatite
    • -10% calcium
  31. Rickets
    • Soft bones due to calcium salts
    • Only found in children
  32. Osteogenesis Imperfecta
    • Brittle Bone Disease
    • excessively brittle bones due to lack of protein, collagen
  33. Ceramic Polymer Composition
    • Ceramic: hydroxyapatite and calcium
    • Polymer: collagen
    • makes bones tough but slightly flexible so they don't break
  34. Perforating Canals (Volkmann)
    Transverse or diagonal canals carrying blood and nerves through bones
  35. Central Canals
    Run up and down long bones a carrying blood and nerves through bone
  36. Spicules
    Slivers of spongy bone
  37. trabeculae
    • Thin plates in spongy bone
    • Develop along lines of stress
  38. Bone Marrow
    soft tissue that occupies the marrow cavity of long bones and small spaces amid trabeculae of spongy bone
  39. Red Bone Marrow (myeloid tissue)
    • Found in the skull, vertebrae, ribs, sternum, pelvic girdle, proximal heads of humerus and femur
    • produces blood cells
  40. Yellow Bone Marrow
    • Only found in adults
    • Composed of adipose tissue
    • No longer produces blood
  41. Ossification
    bone formation
  42. Intramembranous Ossification
    • Formation of Flat Bones
    • 1. Condensation of mesenchyme into soft sheets permeated with blood capillaries
    • 2. Deposition of osteoid tissue by osteoblasts on mesenchymal surface; entrapment of first osteocytes
    • 3. Honeycomb of bony trabeculae formed by continued mineral deposition; creation of spongy bone
    • 4. Surface of bone filled by bone deposition, converting spongy bone to compact bone. Spongy bone in the middle
  43. Endochondral Ossification
    • 1. Early cartilage model consisting of perichondrium and hyaline cartilage
    • 2. Formation of primary ossification center, bony collar, and periosteum
    • 3. Vascular invasion, formation of primary marrow cavity and secondary ossification center
    • 4. Bone at birth, with enlarged primary marrow cavity and appearance of secondary marrow cavity
    • 5. Bone of a child, with epiphyseal plate at distal end
    • 6. Adult bone with single marrow cavity and closed epiphyseal plate
  44. Metaphysis
    zone of transition facing the marrow cavity
  45. Zones of Metaphysis
    • 1. Zone of reserve cartilage
    • 2. Zone of cell proliferation
    • 3. Zone of cell hypertrophy
    • 4. Zone of calcification
    • 5. Zone of bone deposition
  46. Interstitial Growth
    Bone growth in length from the epiphyseal line
  47. Appositional Growth
    Bone increase in width by laying down circumferential lamellae
  48. Wolff's Law
    Architecture of bone determined by mechanical stress placed on it and bones adapt to withstand those stresses
  49. Achondroplastic Dwarfism
    Long bones stop growing in childhood
  50. Pituitary Dwarfism
    • Lack of growth hormone
    • Normal proportions
  51. Growth Hormone
    stimulates protein synthesis and cell growth throughout the body
  52. Thyrocine
    stimulates cell metabolism and increase osteoblast activity
  53. Estrogen and Testosterone
    stimulate osteoblasts to produce bone faster causing epiphyseal plate to close
  54. Abnormal (Ectopic) Calcification
    Bone deposition outside of bones
  55. Mineral Resorption
    the process of dissolving bone and releasing minerals into the blood
  56. Hypocalcemia
    • Too much calcium in the blood
    • causes excessive excitability of nervous system leading to muscle spasms and tremors
  57. Hypercalcemia
    • Too little calcium in the blood
    • Sodium channels are less likely to open. depressing nervous system
  58. Calcitriol
    • A form of Vitamin D produced from the skin, liver, and kidneys
    • Allows body to absorb calcium from food
  59. Calcitonin
    • Secreted by C ells of the thyroid gland when calcium levels in the blood are too high
    • inhibits osteoclasts from dissolving bone
    • increases the number of osteoblasts to deposit calcium into the skeleton
  60. Parathyroid Hormone (PTH)
    • Secreted by the parathyroid gland when blood calcium reaches too low
    • Raises blood calcium level by stimulating osteoclasts
  61. Stress Fracture
    Break caused by abnormal trauma to a bone
  62. Pathological Fracture
    break in a bone that has been weakened by some other disease
  63. Healing of fractures
    • 1. Hematoma formation
    • 2. Soft callus made of collagen
    • 3. Hard calls formation
    • 4. Bone remodeling
  64. Closed Reduction
    Bone fragments are manipulated into their normal position without surgery
  65. Open Reduction
    Opening a fracture surgically to put the bones back together using pins and plates
  66. Orthopedics
    Branch of medicine that deals with prevention and correction of injuries and disorders of the bones, joints, and muscles
  67. Electrical Stimulation
    • accelerates bone repair
    • suppresses effects of parathyroid hormone
  68. Osteoporosis
    severe loss of bone density
Card Set
Bone Tissue
Anatomy and Physiology by Saladin Chapter 7 vocab