Histo- Muscle.txt

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Histo- Muscle.txt
2014-11-11 16:06:31
muscle histo

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  1. 4 functions muscle provides to organs.
    movement, maintenance of posture, joint stabilization, heat generation (shivering)
  2. What are the 4 specialized characteristics of muscle?
    contractility (shortening), excitability (electrical impulse through nerve fibers), extensibility (PASSIVE stretching w/ contraction of opposing muscle), elasticity (recoils passively after being stretched)
  3. Locations of skeletal muscles.
    attachments to bones, abdominal wall, esophagus
  4. Location of cardiac muscle.
  5. Location of smooth muscles.
    Tubular organs (GI and repro tract), hair follicles, Eye, Vasculature
  6. Muscle cell type that provides contractile ability to small structures.
  7. Example of myoepithelium.
    around mammy gland epithelium to provide alveoli with ability to squeeze out milk products
  8. Myoepithelium is made of _______ or _______ epithelium.
    columnar or cuboidal
  9. Connective tissue cells which have contractile ability; function in third-intention healing wounds.
  10. Muscle cells are called _________- because they are elongated.
  11. Contraction of muscles depends on _______, which include...
    myofilaments; actin and myosin
  12. The plasma membrane of a muscle cell is called the _______.
  13. Skeletal muscle fibers are ___________ because the embryonic cells fuse.
  14. Skeletal muscles cells have obvious _______ and contractions are ________.
    striations; voluntary
  15. When a muscle span two or more joints, it is called _________.
  16. Muscle attachment that is so short that the muscle appears to attach directly to the bone.
    Direct or "fleshy" attachment
  17. Muscle attachment in which the connective tissue extends well beyond the muscle.
    Indirect attachment
  18. Example of direct attachment of muscles.
    intercostal muscles
  19. Example of indirect muscle attachment.
    flexors and extensors of the antebrachium
  20. 2 types of indirect muscle attachments.
    tendons, aponeurosis
  21. Skeletal muscles structure from biggest to smallest.
    myofiber --> myofibrils --> myofilaments --> sarcomeres
  22. _________ are the organelles of the skeletal muscle cell; made up of ______.
    myofibrils; filaments
  23. The basic unit of skeletal muscle contraction
  24. Myofibrils are long rows of repeating _________
  25. Boundaries of sarcomeres are called _______.
    Z discs (or lines)
  26. 3 types of filaments that make up myofibrils and sarcomeres.
    myosin (thick), actin (thin), titin (elastic)
  27. Sarcomere structure applies to......., but not....
    skeletal and cardiac muscles; smooth muscle
  28. Proteins of the sarcomere (4)
    myosin, actin, troponin, tropomyosin
  29. During sarcomere contraction, ___________ get closer together and ________ get smaller.
    Z bands; I bands
  30. Invaginations of sarcolemma into the cell.
    T tubules
  31. T tubules form a tubular network inside the muscle cell at the junction of...
    the A and I bands
  32. The T system formed by T tubules allows for...
    conduction of depolarization impulses for simultaneous contraction of sarcomeres
  33. Sarcoplasmic reticulum is synonymous with _______.
    smooth endoplasmic reticulum (HOWEVER, only in muscle cells is it called this)
  34. The tubules of the sarcoplasmic reticulum surround ________ and form channels called _________, which serve the purpose to....
    myofibrils; terminal cisternae; store Ca+ and release it when the muscles are stimulated to contract
  35. Motor neutrons innervate __________ and meet at a __________.
    muscle fibers; motor end plate
  36. Neurotransmitters are released by nerve signals and initiate...
    calcium ion release and muscle contraction
  37. A motor neuron and all the muscle fibers it innervates.
    motor unit
  38. The finer the movement, the ________ the muscle fibers/motor unit.
  39. Release of neurotransmitters initiates the...
    T system and ultimately, contraction
  40. The types of skeletal muscle fibers are..., and they are grouped based on...
    fast, slow, and intermediate-twitch fibers; whether or not they predominantly use oxygen to produce ATP
  41. Large, predominantly anaerobic muscle fibers that fatigue rapidly majority of skeletal muscle fibers.
    fast fibers (white muscle)
  42. Smaller skeletal muscle fibers that can continue contracting; rely on aerobic metabolism, contain moe mitochondria and myglobin.
    slow fibers (red muscle)
  43. The amount of tension a muscle provides when contracted is based upon...
    the frequency of stimulation (how many stimulations are happening); the number of motor unit involved (providing range of motion, rather than all or nothing)
  44. The amount of force provided by a muscle depends on...
    how many motor units are activated
  45. Even at rest, some muscle units are active and tense even though they are not causing movement.
    resting tone
  46. Cardiac muscle function to...
    reduce the size of the chambers of the heart
  47. Cardiac muscle is a system of ________ and _________ similar to skeletal muscle.
    sarcomeres and sarcoplasmic reticulum
  48. In cardiac muscle, bundles form thick _______.
  49. What are 3 major differences between skeletal and cardiac muscle?
    • 1. cardiac muscle cells are single cells joined together at intercalated discs; skeletal muscle cells share cytoplasm/are actually fused.
    • 2. cardiac muscle cells branch; skeletal muscle cells are elongated on one axis.
    • 3. cardiac muscle cells have nuclei at the center; skeletal muscle cell nuclei are pushed off to the side of the cell.
  50. The fact that cardiac muscle cells each beat separately without any stimulation.
    inherent rhythmicity
  51. Intercalated discs are only present in _________ and provide...
    cardiac muscle; sites of attachment for cardiac muscle cells
  52. Intercalated discs join cells together in order to...
    allow for simultaneous contraction
  53. Highly modified cardiomyocytes that are part of the conduction system of the heart.
    purkinje fibers
  54. Purkinje fibers lack ___________, and they are connected by __________ and ___________ instead of __________.
    T tubules; gap junctions and desmosomes; intercalated discs
  55. There are 2 layers of smooth muscle in tubular organs. What are the layers and hat is their function?
    • 1. Outer longitudinal layer- reduces length
    • 2. Inner, circular layer- reduces diameter

    Together, they move food, fluid, etc through the tubular organ
  56. Smooth muscle cells are _______-shaped (like fibroblasts), but unlike fibroblasts, they have...
    spindle; a large amount of cytoplasm
  57. Smooth muscle contractions are ________ and ________, and they do not always require a ________.
    slow and sustained; nervous signal
  58. What is the difference between smooth muscle contraction and skeletal muscle contraction?
    As smooth muscle filaments contract, the entire cell shrinks in all directions; as skeletal muscle fibers contract, the muscle shorts longitudinally due to sarcomeres
  59. In smooth muscle contraction, calcium binds to ________, and this complex activates ___________, which phosphorylates ________ and allows it to bind to _______.
    calmodulin; myosin light chain kinase (MLCK); myosin; actin
  60. In skeletal muscles, myosin heads bind to actin in the presence of ________, and the sarcomeres contract in...
    calcium; one direction