Biology: Musculoskeletal

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Biology: Musculoskeletal
2010-06-08 11:03:45
Biology Musculoskeletal

Biology: Musculoskeletal
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  1. The axial skeleton is the basic framework of the body, consisting of the ____________ , _____________, and _____________.
    • Skull
    • Vertebral column
    • rib cage
  2. Cartilage
    • composed of firm but elastic matrix called chondrin
    • chondrin is secreted by specalized cells called chondrocytes
    • cartilage is the principal component of embryonic skeletons in higher animals - hardens and calcifies into bone
    • Cartilage reamins in external ear, nose, walls of the larynx, and trachea, and skeletal joints contain cartilage
    • most cartilage is avascular - contains no blood or lymph vessels, and is devoid of nerves
    • *receives nourishment from capillaries located in nearby CT and bone via diffusion through the surrounding fluid.
  3. Most cartilage is avascular, containing no blood or lymph vessels, and is devoid of nerves.
    A. True
    B. False
  4. Cartilage receives nourishment from capillaries located in nearby CT and bone via _______ through surrounding fluid.
  5. _______________, also called cancellous bone, consists of interconnecting lattice of bony spicules called ______________.
  6. ______________ bone marrow is inactive and infiltrated by adipose tissue.
    Yellow bone marrow
  7. _____________ is involved in blood cell formation.
    Red bone marrow
  8. The bones of the appendages are called _____________.
    Long bones
  9. The shaft of the long bone is called a _________________.
  10. The dilated ends of long bones are called epiphyses
  11. The diaphysis is composed primarily of __________________.
    Compact bone surrounding a cavity containing bone marrow.
  12. The ______________ are composed of spongy bone surrounded by a thin layer of compact bone.
  13. The ____________________ is a disk of cartilaginous cells separating the diaphysis from the epiphysis, and is the site of longitudinal growth.
    epiphyseal plate
  14. A fibrous sheath called the _________________ surrounds the long bone, and is the site of attachment to muscle tissue.
  15. Some periosteum cells differentiate into ____________________.
    Bone-forming cells
  16. Compact bone is composed of dense, hardened bone matrix, which contains both ___________ and _____________ components.
    Organic and Inorganic components
  17. In compact bone, the organic components include ______________.
    Proteins: collagen fibers, glycoproteins
  18. In compact bone, inorganic components include _________________.
    • calcium, phosphate, hydroxide (which combine and harden to form hydroxyapatite crystals)
    • sodium, potassium, magnesium ions
  19. The association of __________ and ____________ gives bone its characteristic strength
    hydroxyapatite crystals and collagen fibers
  20. The bony matrix is deposited in structural units called ____________, also known as Haversian systems.
  21. Each osteon consists of a microscopic channel called a _________________.
    Haversian canal - surrounded by a number of concentric circles of bony matrix called lamellae
  22. The Haversian canal is surrounded by a number of concentric circles of bony matrix called _____________.
  23. There are _____________, ________________, and _____________ in the Haversian canals, vascularizing and innervating bone tissue.
    • Blood Vessels
    • Nerve fibers
    • Lymph
  24. Radiating from each lacuna are a number of minute canals called __________________.
  25. The _____________ interconnect with each other and with Haversian canals, allowing exchange of nutrients and wastes.
  26. ________________ synthesize and secrete organic constituents of the bony matrix.
    • Osteoblast - form bone
    • *once they are surrounded by their matrix, they mature into osteocytes
  27. ________________ are large multinucleated cells involved in bone resorption (destroy bone!)
  28. Bone formation occurs by either ___________________ or by ____________________.
    • Endochondral ossification
    • Intramembranous ossification
  29. In _____________________, existing cartilage is replaced by bone.
    Endochondral ossification
  30. Long bones arise primarily through ______________________.
    Endochondral ossification
  31. In ________________________, mesenchymal (embryonic, undifferentiated) connective tissue is transformed into and replaced by bone.
    Intramembranous ossification
  32. During __________________, inorganic ions (i.e. calcium and phosphate) are absorbed from the blood for use in bone formation.
    Bone reformation
  33. During ___________________, inorganic ions (i.e. calcium, phosphate) are released into the blood.
    Bone resorption (degradation)
  34. ______________, and hormones, ___________ and ______________, are all involved in the regulation of bone remodeling (forming, and destroying).
    • Vitamin D
    • Parathyroid hormone
    • Calcitonin
  35. The freely movable _________ joints, the two bones are separated by a cavity.
    Synovial joints
  36. An example of a synovial joint is ______________.
    the knee.
  37. Synovial joints are subject to _____________.
  38. ______________ ease friction between tendons and ligaments and between tendons and bones.
  39. The knee and elbow are _______________ because they largely permit movement in one direction.
    Hinge joint

    knee-synovial joint
  40. _____________ joints allow movement in all planes and even rotational movement.
    • Ball and socket
    • examples: ball of femur, shoulder
  41. The skeletal muscle is innervated by the __________________.
    Somatic nervous system
  42. The cytoplasm of a muscle fiber is called _____________.
  43. The cell membrane of a muscle fiber is called the ____________________.
  44. The __________________ is capable of propagating an action potential, and is connected to a system of transverse tubules (T system) oriented perpendicularly to the myofibrils.
  45. The __________________ provides channels for ion flow throughout the muscle fibers, and can also propagate an action potential.
    T system
  46. Skeletal muscles can be characterized as either red or white.
    A. True
    B. False
  47. Red skeletal muscle fibers are abundant in ___________ content, and _____________.
    • Myoglobin - store oxygen
    • mitochondria
  48. _______________ derive their energy from aerobic respiration and are capable of sustained and vigorous activity.
    Red skeletal muscle fibers : "slow-twitch fibers"
  49. ___________________ contain less myoglobin and fewer mitochondria.
    White skeletal muscle fibers
  50. ________ skeletal muscle fibers are anaerobic.
    White fibers
  51. Which of the following has a greater rate of contraction?
    A. White skeletal fibers
    B. Red skeletal fibers
    White skeletal fibers
  52. Which of the following fatigues more easily ?
    A. White skeletal muscle fibers
    B. Red Skeletal muscle fibers
    white fibers
  53. The ______________ is composed of thin and thick filaments.
  54. The thin filaments of the sacromere are the ____________.
    Actin filaments
  55. Actin filaments are associated with two proteins: _________________, ________________.
    • troponin
    • tropomyosin
  56. The thick filaments are composed of organized bundles of ____________.
    • Myosin molecules
    • *each myosin molecule has a head region and a tail region.
  57. In the sacromere, the ________________ define the boundaries of a single sacromere and anchor the thin filaments.
    Z lines
  58. ______________ runs down the center of the sacromere.
    M line
  59. In the sacromere, the ___________ is the region containing thin filaments only.
    I band
  60. In the sacromere, the _______________ is the region containing thick filaments only
    H zone
  61. In the sacromere, the _______________ spans the entire length of the thick filaments and any overlapping portions of the thin filaments.
    A band.
  62. During skeletal muscle contraction, the ______________ is not reduced, while the H zone and are reduced.
    A band. a
  63. During skeletal muscle contraction, the ____________, and ___________ are reduced in size.
    H zone, and I band
  64. _________________ break down ATP and form cross bridges that attach to and pull the actin filaments toward the center of the sacromere.
    Myosin filaments
  65. Muscle fibers rely on _______________, a storage form of high-energy phosphate for energy.
    • creatine phosphate. - cannot participate directly in muscle contraction.
    • It anaerobically regenerates ATP by :
    • creatine-P + ADP -------> ATP + creatine
    • *this is the speediest energy source available to muscles.
  66. Muscle contraction is stimulated by a message from the _________________ sent via a motor neuron.
    Somatic nervous system
  67. During muscle contraction, the sarcolemma of the muscle fiber is called the _____________________.
    Neuromuscular junction
  68. ________________ of the motor neuron results in the release of neurotransmitters from the nerve terminal.
    • Depolorization
    • *The neurotransmitter diffuse across the synaptic cleft and binds to special receptor sites on the sarcolemma.
    • *If enough of these receptors are stimulated, the permeability of the sarcolemma is altered and an action potential is generated.
  69. During muscle contraction, once an action potential is generated, it is conducted along the ____________, and the ____________, and into the inferior of the muscle fiber.
    Sarcolemma, T system
  70. During contraction, the generation of the action potential causes the ______________ to release Ca2+ into the sarcoplasm.
    sarcoplasmic reticulum
  71. The Ca2+ binds to the ______________.
    a. troponin
    b. tropomyosin
  72. ATPase Activity
    5 steps:
    • 1. resting stage - ATP is hydrolyzed when myosin head is unattached
    • 2. Ca2+ binds to troponin; myosin binds to actin
    • 3. powerstroke occurs; sacromere contracts
    • 4. ADP and P are released
    • 5. New ATP binds to myosin, causing detachment of myosin from actin;
    • Relaxation
  73. What is the function of Ca2+ in muscle contraction?
    Troponin-Ca2+ complex pulls tropomyosin away, exposing myosin binding sites
  74. Individual muscle fibers generally exhibit an ____________ response.
    all or none response - only a stimulus above threshold value can elicit contraction.
  75. The strength of the contraction of a single muscle fiber cannot be increased, regardless of the strength of the stimulus.
    A. true
    b. false
  76. Whole muscle exhibits an all or none response.
    a. true
    b. false.
    • false
    • *although there is a minimal threshold value needed to elicit a muscle contraction, the strength of the contraction can increase as stimulus strength is increased by involving more fibers.
  77. A ______________________ is reached when all the fibers have reached the threshold value and the muscle contracts as a whole.
    Maximal response
  78. __________ refers to the continual low-grade contractions of the muscle, which are essential for both voluntary and involuntary muscle contraction.
    • Tonus
    • *Even at rest, muscles are in a continuous state of tonus
  79. A ________________ is the response of a single muscle fiber to a brief stimulus at or above the threshold stimulus.
    Simple twitch
  80. A simple twitch consists of 3 periods:
    1. ________________
    2. ________________
    3. ________________
    • 1. latent period
    • 2. contraction period
    • 3. relaxation period
  81. During a simple twitch, the time between stimulation and the onset of contraction is the ___________ period.
    Latent period
  82. During the ____________ period in a simple twitch, the action potential spreads along the sarcolemma and Ca2+ ions are released.
    latent period
  83. Following the contraction in a simple twitch, there is a brief relaxation period in which the muscle is unresponsive to stimulus, this is known as the ______________.
    Absolute refractory period.
  84. Following the absolute refractory period in a simple twitch, a _____________ occurs, during which a greater than normal stimulus is needed to elicit a contraction.
    relative refractory period
  85. When the fibers of a muscle are exposed to a very frequent stimuli, the muscle cannot fully relax.
    A. true
    B. false
    • true
    • *the contractions begin to combine, becoming stronger and more prolonged. This is known as frequency summation.
  86. A tetanus contraction is stronger than a simple twitch of a single fiber.
    a. true
    b false.
    • true
    • *If tetanization is prolonged, the muscle will begin to fatigue
  87. Smooth muscle is innervated by ________________.
    Autonomic nervous system
  88. _____________ possess one centrally located nucleus.
    Smooth muscle
  89. Smooth muscles also contain actin and myosin filaments.
    a. true
    b. false
    • true
    • *however, these filaments lack the organization of skeletal sarcomeres; thus, lacking striations.
  90. All muscle contractions by skeletal, smooth, and cardiac require Ca2+ for contraction.
    a. true
    b. false
  91. ____________ muscle contains many nuclei per cell.
    Skeletal muscle
  92. Smooth muscle contractions are slower, and are capable of being sustained longer than skeletal muscle contractions.
    a. true
    b. false
  93. ________________ muscle typically have both inhibitory and excitatory synapses that regulate contraction via the nervous system.
    Smooth muscle
  94. _______________ muscle also have the property of reflexively contracting without the nervous stimulation; this is called myogenic activity.
    • Smooth muscle
    • *also cardiac muscle !!!!!!! has myogenic activity
  95. Like skeletal muscle, ____________ muscle have actin and myosin filaments that are arranged in sacromeres, giving the striation look.
  96. ___________ muscle contains 1-2 nuclei (centrally located) per cel.
  97. Cardiac muscle is innervated by the _________________.
    • autonomic nervous system
    • *cardiac muscle is also myogenic - has the property of reflexively contracting without nervous stimulation
  98. ______________ has a high O2 affinity.
    • myoglobin -binds to O2 from the bloodstream and holds onto it.
    • *During strenuous exercise, when muscle cells rapidly run out of available O2, myoglobin releases its O2.
    • *If the oxygen supply to muscles become insufficient to meet its energy standards, the muscle obtains additional energy via anaerobic respiration, resulting in the build-up of hte lactic acid.
  99. Connective Tissue:

    ________________ binds epithelium to underlying tissues and is the packing material that holds organs in place.
    Loose connective tissue
  100. Loose connective tissue contains 3 types of fibers :
    1. ________________
    2. ________________
    3. ________________
    • 1. collagenous fibers
    • 2. elastic fibers
    • 3. reticular fibers
  101. Connective tissue:

    ______________ fibers are composed of collagen and have great tensile strength.
    collagenous fibers
  102. Connective Tissue:

    _______________ fibers are composed of elastin and endow connective tissue with resilience
    Elastic fibers
  103. Connective tissue:

    ________________ fibers, which are branched, tightly woven fibers that join connective tissue to adjoining tissue.
    Reticular fibers
  104. There are two major cell types in loose connective tissue:
    1. _________________
    2. _________________
    • 1. fibroblasts
    • 2. macrophages
  105. In loose connective tissue, ____________ secrete substances that are components of extracellular fibers
  106. In loose connective tissue, _______________ engulf bacteria and dead cells via phagocytosis.
  107. _______________ is a connective tissue with very high proportion of collagenous fibers.
    Dense connective tissue
  108. Connective Tissue:

    _________________ fibers are organized into parallel bundles that give the fibers great tensile strength.
    Dense connective tissue
  109. __________________ tissue forms tendons, which attach muscle to bone.
    Dense connective tissue
  110. ____________ attach muscle to bone.
  111. ___________ hold bones together at joints
  112. A _________ muscle will contract to decrease the angle of a joint.
    flexor muscle
  113. A __________ muscle will contract to straighten the joint.
  114. An _____________ moves a part of the body away from the body's midline.
  115. An ______________ moves a part of the body toward the midline.
  116. _______________ are bone cells involved in the secretion of bone matrix.
  117. _______________ serves as the site of attachment of bone to muscle.
  118. Cells of the _______________ differentiate into osteoblasts
  119. The ________________ is a fibrous sheath that surrounds long bones.