A&P Chapter 6-9

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A&P Chapter 6-9
2014-02-26 22:23:46
Bones Skeletal

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  1. Describe the six main functions of the skeletal system?
    support, protection, assistance in movement,  mineral homeostasis, blood cell production, and triglyceride storage
  2. What are the minerals that are stored or released?
    calcium and phosphorus
  3. Describe the structure and functions of each part of a long bone?
  4. Bone Tissue Functions
    Homeostatic contributions; provide support, protection, production of blood cells, storage of minerals and triglycerides
  5. What is bone tissue?
    Bone (osseous tissue)cartilage dense connective tissues, epithelium, adipose tissue and nervous tissue make up 18% of weight of the human body
  6. What is remodeling
    the construction of new bone tissue and the breaking down of old bone tissue
  7. the skeletal system
    composed of bones and their cartilages ligaments and tendons
  8. Osteology
    the study of bone structure and the treatment of bone disorders
  9. Support
    skeletal structural framework supports soft tissues, provides attachment points for tendons of most skeletal muscles
  10. protection
    skeletal function that protects most important internal organs from injury
  11. Assistance in movement
    skeletal muscles attach to bones; upon muscle contraction they pull on bones to produce movement
  12. Mineral storage and release
    On demand, bone releases minerals in to the blood to maintain critical mineral balances (homeostasis) and distribute the minerals to other parts of the body
  13. Calcium and Phosphorus Minerals
    Bone tissue mineral storage calcium and phosphorus strengthen bones, stores 99% of the body's calcium
  14. blood cell production
    red bone marrow consist of developing blood cells adipocytes fibroblast, and macrophages within a network of reticular fibers
  15. red bone marrow
    produces red blood cells, white blood cells and platelets in the process called hemopoiesis
  16. Red bone marrow locations
    developing fetus, adult bones, hip bones ribs, breastbone, vertebrae, skull, ends of  bones, of the arm, and thigh
  17. Triglyceride storage
    potential chemical energy reserve, with increasing age much of the red bone marrow turns yellow, Vitamin A makes it yellow
  18. Yellow Bone Marrow
    consists mainly of adipose cells, which store triglycerides
  19. Long Bones
    longer than they are wide, act as levers and shock absorbers mostly compact bone with spongy bone at the ends.
  20. location of long bones
    thighs, legs, toes, upper arms, forearms, and fingers
  21. Parts of a long bone
    diaphysis, epiphyses, metaphyses, articular cartilage, periosteum, medullary cavity, endosteum.
  22. Diaphysis
    the bones shaft or body (long cylindrical, main portion of the bone) contains the medullary marrow cavity (in adults the MC contains the yellow bone marrow)
  23. Epiphyses
    the proximal and distal ends of the bone
  24. Metaphyses
    the regions between the diaphysis and the epiphyses contains the epiphyseal growth plate or epiphyseal line
  25. Epiphyseal growth plate
    a layers of hyaline cartilage that allows the diapysis of bone to grow in length; last part to turn into bone always actively to change cartilage into bone until hit puberty
  26. Epiphyseal line
    when the bone ceases to grow in length (age 18-24) is the replacement of the epiphyseal plate into a boney structure
  27. Articular cartilage
    thin layer of hyaline cartilage that cover the part of the epiphysis where the bone forms an articulation joint with another bone reduces friction and absorbs shock at freely moveable joints
  28. Periosteum
    surround the external bone surface wherever it is not covered by articular cartilage protects the bone assists in fracture repair, helps nourish bone tissue, and serves as an attachment point for ligaments and tendons
  29. Periosteum Composition
    Outer fibrous layer of dense irregular connective tissue; inner osteogenic layer consists of cells some cells enable bone growth in thicknes but not in length
  30. Perforating (Sharpey's fibers)
    thick bundles of collagen fibers that  extend from the periosteum into extracellular bone matrix provide attachment of the periosteum to the underlying bone
  31. Medullary Cavity/ Marrow Cavity
    a hollow, cylindrical space within the diaphysis that contains fatty yellow bone marrow in adults
  32. Endosteum
    is a thin membrane that lines the internal bone surface facing the medullary cavity, contains a single layer of cells and a small amount of connective tissue
  33. Bone (Osseous) Tissue
    Contains an abundant extracellular matrix that surrounds widely separated cells
  34. Extracellular matrix of bone tissue
    15% water 30 % collagen fibers and 55% crystallized mineral salts
  35. Types of cells present in bone tissue
    osteogenic cells, osteoblasts, osteocytes and osteoclasts
  36. Osteogenic cells
    unspecialized stem cells derived from mesehchyme found along the inner portion of the periosteum in the endosteum, and in the canals within the bone that contain blood vessels, the only bone cells that goes through cell division, give rise to all bone cells
  37. Mesenchyme
    the tissue from which almost all connective tissue are formed
  38. Genic
  39. Osteoblasts
    bone-building cells, synthesize and secrete collagen fibers and other organic components needed to build the extracellular matrix of bone tissue, initiates calcification, surrounds themselves within their own extracellular matrix become osteocytes
  40. the ending -blasts
    in the name of a bone cell or any other connective tissue cell means that the cell secretes extracellular matrix
  41. Osteocytes
    mature bones cells the main cells in bone tissue and MAINTAIN its daily metabolism such as the exchange of nutrients and wastes with blood
  42. the ending -cytes
    in the name of a bone cell or any other tissue cell means that the cell maintains the tissue
  43. Osteoclasts
    Bone-destroying cells that contain lysomes and phagocytic vacuoles that demineralize bone tissue, help regulate blood calcium level. are target cell for drug therapy to treat osteoporosis
  44. Resorption
    Part of normal development, maintenance, and repair  of bone
  45. the ending -clasts
    in a bone cell means that the cell breaks down extracellular matrices
  46. Compact Bone
    Strongest form of one tissue. Provide protection and support and resists the stresses produced by weight and movement. Found beneath the periosteum of all bones and make up the bulk of the diaphyses of long bones
  47. Perforating or Volkmann's Canals
    Allows blood vessels, lymphatic vessels, and nerves from the periosteum to penetrate compact bones
  48. Central or Haversian Canals
    Run longitudinally through the bone
  49. Concentric lamellae
    Around the central canals are rings of calcified extracellular matrix much like the rings of a tree trunk
  50. Lacunae
    Contain osteocytes. Small spaces between lamellae.
  51. Canaliculi
    Small channels filled with extracellular fluid. Inside contains slender fingerlike processes of osteocytes. Connects lacunae with one another and with the central canals, provides routes for nutrients and oxygen to reach the osteocytes and for the removal of wastes
  52. Two types of Bone Tissue
    Compact Bone Tissue and Spongy Bone tissue
  53. Components of Compact Bone
    Osteons/ Haversian systems: Repeating structural unitis
  54. Osteons
    (resembles a stack of logs) Consists of a central (haversian) canal, with arranged lamellae, lacunae, osteocytes, and canaliculi. they are aligned in the same direction along lines of stress which helps the long bone resist bending or fracture. Changes over time in response to the physical demands placed on the skeleton
  55. Interstitial Lamellae
    Area between osteons. Fragments of older osteons that have been partially destroyed during bone rebuilding or growth
  56. Circumferential Lamellae
    Rings of hard calcified matrix found just beneath the periosteum and in the medullary cavity
  57. Spongy Bone Tissue
    Does not contain osteons, Consists of lamellae trabeculae surrounding many red bone marrow-filled spaces.
  58. Spongy Bone
    Short, flat, and irregular bones and the interior of the epiphyses in long bones
  59. Spongy Bone tissue Trabeculae
    Offer resistance along lines of stress, support and protect red bone marrow, and make bones lighter for easier movement
  60. Periosteal Arteries
    Accompanied by nerves enter the diaphysis through many perforating (Volkmann's) canals. Supply the periosteum and outer parts of the compact bone
  61. Nutrient Artery
    Near the center of the diaphysis; Divides in the medullary cavity into proximal and distal branches. Supplies both the inner part of the compact bone tissue of the diaphysis and the spongy bone tissue and red marrow as far as the epiphyseal plats
  62. Nutrient Foreman
    An opening in the shaft of the bone allowing an artery to pass into the one
  63. Metaphyseal and Epihyseal Arteries
    BOTH supply the ends of long bones, which arise from arteries that supply the associated joint
  64. Epiphyseal Arteries
    Enter the Epiphyses of long bone and supply the red bone marrow and bone tissue of the epiphyses
  65. Blood Supply of Bone
    Long bones are supplied by periosteal, nutrient, metaphyseal, and epiphyseal arteries; veins accompany the arteries.
  66. Nerve Supply of Bone
    Nerves accompany blood vessels in bone; the periosteum is rich in sensory neurons. Some of which carry pain sensations.
  67. Bone Flexibility
    Depends on its collagen fibers
  68. Tensile Strength
    Provided by collagen fibers and other organic molecules resistance to being stretched or torn apart
  69. Ossification
    Bone formation develops by either ENDOCHRONDRAL ossification or INTRAMEMBRANOUS (dermal) ossificationbegins during the fourth week of prenatal development.
  70. Endochrondral Ossification
    Bone development first through a cartilaginous stage. Begins in a primary center in the shaft of the cartilage model with hypertrophy of chondrocytes (cartilage cells) and calcification of the cartilage matrix. The cartilage model is then vascularized, osteogenic cells form a bony collar around the mode, and osteoblasts lay down bony matrix around the calcareous spicules. The formation of most bones
  71. Intramembranous (dermal) Ossification
    Forming directly as a bone. (Facial bones, most cranial bones, and the clavicle)
  72. Endochrondral Osssification
    Ossification from primary centers occurs before birth; from secondary centers in the epiphyses, it occurs during the first 5 years.
  73. Metaphyses of a long bone and nutrient artery
    both supply the red bone marrow and bone tissue of the metaphyses
  74. Metaphyseal arteries
    enter the metaphyses of a long bone
  75. Bone hardness
    depends on the crystallized in organic mineral salts
  76. Tensile Strength
    Provided by collagen fibers and other organic molecules. Resistance to being stretched or torn apart.  
  77. Intramembranous
    ossification center – mesenchymal cells differentiate into        osteoblasts that secrete matrix that fuses into spongy bone; mesenchymal cells invade and form blood vessels; periosteum develops; layer of spongy bone inside periosteum becomes compact bone
  78. . Endochondral
    mesenchymal cells differentiate into chondroblasts which lay down matris (= hyaline cartilage); a fibrous membrane(perichondrium) forms around this”model”;the cartilage model grows; at center of diaphysis, chondrocytes enlarge and secrete Ca salts to make matrix hard and thereby isolating themselves; they die; a nutrient artery penetrates perichondrium and invades matrix and branch off into capillaries; fibroblasts follow into ossification center and differentiate into osteoblasts which lay down matrix, forming spongy bone; osteoclasts form medullary cavity which fills with red bone marrow; area inside periosteum (formerly called perichondrium) becomes a bony collar which forms lamellae of compact bone; each epiphysis has its own ossification ctr which repeats this process after birth
  79. Growth by remodeling
    appositional and longitudinal from the epiphyseal plate (the place where the diaphysis and epiphysis meet); this plate calcifies at end of puberty and becomes the epiphyseal line and longitudinal growth stops
  80. Growth hormone
    Effect: stimulates liver to secrete somatomedin and causes cartilage to proliferate at epiphyseal plate (bone elongation)Mechanism: Increase osteoblast activity
  81. Thyroid
    Effect: stimulate bone growth Mechanism: increase osteoblast activity
  82. Calcitonin
    Effect: promotes Ca+ deposition Mechanism: decrease osteoclast activity and decreases blood calcium levels
  83. Parathyroid Hormone
    Effect: increases Ca levels by encouraging bone resorption by osteoclasts Mechanism: increase osteoclast activity and increases blood calcium levels
  84. Sex hormones (estrogen and testosterone)
    Effect: promotes epiphyseal plate growth and closure Mechanism: increase osteoblast activity
  85. Glucocorticoids
    Effect: increases bone loss; in children can impair bone growth Mechanism: increases osteoclast activity
  86. Serotonin
    inhibits osteoprogenitor cells from differentiating into osteoblasts when there are chronically high levels of serotonin
  87. Fracture Repair Steps
    Fracture hematoma, fibro cartilaginous callus, bony callus, bone remodeling
  88. Explain the repair steps
    • §  Once you stabilize the area you will have a clot called a hematoma it stabilizes and activates the osteoblast and clasts
    • §  Phagocytes remove cellular debris and fibroblasts deposit collagen to form a fibro cartilaginous callus
    • §  Which is followed by osteoblasts forming a bony callus of spongy bone
    • §  Final sstep spongy bone is replaced by compact bone
    • §  Bone heals more rapidly than cartilage because its bloods supply is more plentiful
  89. Types of Fractures
    • o   Partial complete is all the way through the bone
    • o   Closed simple
    • o   Open punctures through the skin
  90. Aging and bone tissue:
  91. o   A decrease in bone mass occurs as the level of sex hormones diminishes during middle age especially women after menopause
    • o   Bone resorption by osteoclasts outpaces bone deposition by osteoblasts
    • o   Since female bones are generally smaller and less massive than males to begin with old age has a greater adverse effect in females
    • o   There are two principals effects of aging on bone tissue
    • §  Loss of bone mass
    • ·         Loss of calcium from bones is one of the symptoms in osteoporosis 
    •   Brittleness 
    • - Collagen fibers have decreased
    • -Bone can also become cancerous and is a fast growing, osteosarcoma
  92. Demineralization
    the loss of calcium and other minerals from bone extracellular matrix.