Skeletal System

  1. Functions of skeletal system
    • protects interal organs
    • serves as anchor for muscle attachments
    • aids in movement
    • stores minerals
    • produces blood cells
  2. connective tissue of skeletal system
    • cartilage
    • ligaments
    • tendons
    • bones
  3. 5 kinds of bones
    • long: (arm and leg)
    • short: (hands and feet)
    • flat: (skull)
    • round: (kneecap)
    • irregular: other
  4. bones contain
    • mineral salts, calcium, phosphate
    • living cells, nerves, and blood vessels
  5. blood cells are produced
    in the interior of bones
  6. compact bone
    • outer hard shell of bone
    • composed of osteons
  7. osteocytes
    bone cells are found in the lacune
  8. lacunae
    • concentric circles around a central canal
    • house osteocytes
    • connect to each other by canaliculi
  9. spongy bone
    • porous (spongy) found on the inner surface and ends of long bones.
    • less dense but still strong becuase of trabeculae
  10. trabeculae
    strengthen spongy bone
  11. red bone marrow
    found in spaces beteween trabeculae
  12. epiphysis
    found at the ends of long bone
  13. diaphysis
    shaft of the long bone
  14. medullary cavity
    • inside diaphysis
    • filled with yellow bone marrow (fat)
  15. periosteum
    • fibrous connective tissue
    • covers bone except at joint surfaces
  16. bone begins to develp
    in utero at 6 weeks old as hyaline cartilage
  17. ossification
    bone replacing cartilage
  18. steps of bone development
    • chondroblast die and matrix dissolves making room for blood vessels
    • periosteum forms and produces osteoblasts
    • osteoblasts + collagen + enzyme that produces hydroxyapatite
  19. chondroblast
    cartilage producing cell
  20. osteoblast
    bone forming cell
  21. hydroxyapatite
    • released by an enzyme that promotes crystalization of calcium phosphate
    • traps osteoblast and forms the lacunae
  22. growth plates zones
    • resting
    • proliferating
    • degenerating
    • ossification
  23. resting zone
    attache epiphyseal plate to bony tissue of epiphysis
  24. proliferating zone
    produces new chrodroblasts
  25. degenerating zone
    cartilage cells die
  26. ossification zone
    bone formation
  27. epiphyseal plate closes
    in women at age 18 and men around 30
  28. sex hormones stimulate
    chrondoblasts and osteoblasts for a growth spurt. osteoblasts grow faster to overtake cartilage.
  29. puberty lasts longer in
    • males
    • women have longer torso allowing for better balance
  30. osteoclasts
    cells that break down bone and minerals are released into the blood
  31. calcium needed for
    • blood clotting, muscle contraction and nerve function
    • when low, osteoclasts break down bone to supply the needed calcium
  32. Parathyroid hormone PTH
    • releases calcium from bone
    • signals kidneys to decrease calcium excretion
  33. calcitonin
    • produced by thyroid
    • decreases calcium concentration in the blood
  34. osteoblasts and osteoclats together
    • maintain calcium levels
    • when high: osteoblasts remove ca from blood and make bone
    • when low: osteoclasts break down bone and release ca into blood
  35. estrogen
    stops osteoclast activity
  36. osteoporosis
    • older women- decline in estrogen- allows osteoclast activity to increase - bone breakdown
    • increases bone breakage
  37. hematoma
    a mass of clotted blood cells
  38. how many bones?
    206 bones
  39. axial skeleton
    • trunk of body
    • skull
    • spine
    • ribs
    • sternum
  40. appendicular skeleton
    • hip
    • shoulder
    • limbs
  41. function of skull
    protect brain and form face
  42. cranium functions to
    • form the upper portion of the skull
    • protects sight smell hearing and tast sense organs
  43. frontal bone
  44. sphenoid
    extends across floor of cranium and attaches to all other skull bones
  45. temporal bone
    near ears
  46. occipital
    skull back base
  47. parietals
    form side of cranium
  48. ethmoid
    helps form the eye orbit and nasal septum- separates nasal cavity
  49. maxillae bone
    • two bones that form much of face.
    • upper jaw and allows for nasals
  50. mandible bone
    lower jaw
  51. zygomatic bone
    cheek bone
  52. sinuses
    air pocket within bones of face
  53. hyoid bone
    • located at the root of the tounge
    • attaches muscles and ligaments is NOT a joint
    • anchors tounge and swallowing muscles
  54. vertebral column
    • 33 vertebrae
    • houses and protects spinal cord
  55. invertebral disks
    fibrocartilaginous pads that cushion the vertebrae
  56. cervical vertebrae
    neck region
  57. thoracic vertebrae
    upper back
  58. lumbar vertebrae
    small of the back
  59. sacrum and cocyx
    bottom of spine
  60. rib cage
    thoracic vertebrae, 12 ribs, and sternum
  61. bottom 2 ribs are
    floating ribs only attached n back
  62. pelvic gridle
    • consists of three fused bones
    • ilium
    • ischium
    • pubis
    • contribute to acetabulum
  63. acetabulum
    cup shaped socket for the head of the femur to form hip joint
  64. tarsal bones
    seven bones form the ankle and heel
  65. metatarsals
    five bones form the arches
  66. phalanges
    toe bones
  67. pectoral girdle
    • scapula (shoulder blade)
    • clavicle (collarbone)
  68. humerus
    long bone of the arm
  69. radius and ulna
    long bones of forearm
  70. carpal bones
    eight bones to form palm and fingers
  71. thumb is
    opposable which permits the grasping of many items with great percision
  72. sutures
    • immovable
    • found between cranial bones
  73. synovial joint
    wide range of motion
  74. hinge joint
    knee and elbow
  75. pivot joints
  76. ball and socket joints
    hips and shoulders
  77. flexion
    decreases joint angle
  78. extension
    increaswes joint angle
  79. adduction
    move toward the midline
  80. abduction
    movement away from midline
  81. rotation
    movement of a body part around its own axis
  82. circumduction
    movement of a body part in a wide circle
Card Set
Skeletal System
ch 6