Anatomy Chapter 19 Mucular system

  1. Antagonistic pairs of muscles
    when one muscle moves in one direction, its antagonist moves in the opposite direction
  2. Synergistic pairs
    muscles work together to bring about movement.
  3. Muscle tone
    • partial contraction of muscle.
    • -Unconscious action
    • -Keeps muscles in a constant state of readiness
    • -Dictates posture
  4. Tonus
    Slight tension in the muscle that is always present, even when at rest.
  5. Flacid (atonic)
    used to describe someone when muscle tone is lacking
  6. Adenosine Triphosphate (ATP)
    a chemical used in muscle contraction.
  7. Lactic Acid
    • a waste product resulting from breakdown of ATP
    • -causes the tired and sometimes burning feeling of muscle fatigue.
  8. Muscle Structure
    • bundles of long muscle fibers
    • -contract (shorten) when stimulated
    • -relax (return to their original position) when stimulus subsides.
  9. Fascia
  10. a fibrous sheath that covers, supports, and separates muscles.
    -Contains the muscle's blood, lymph, and nerve supply.
  11. Myoglobin
    a red pigment in muscles
  12. Tendon
    attaches muscles to bone.
  13. Achilles tendon
    strongest tendon in the body
  14. Hamstrings
    • tendons located behind the knee.
    • -Responsible for extending the hips and flexing the knees.
  15. Aponeurosis
    a wide, flat connective tissue that connects muscle to bone
  16. Neuromuscular junction
    • Where the muscle fiber and nerve ending meet
    • -where synapse occurs
  17. Acetylcholine
    • released at the neuromuscular junction.
    • -used by the nerve endings to send an impulse across the synapse to the muscle.
    • -causes muscle to contract.
  18. Cholinesterase
    breaks down excess acetylcholine and stops overstimulation of muscle.
  19. Isotonic contraction
    • when a muscle shortens and thickens as it contracts.
    • -happens when you life a heavy object.
  20. Isometric contraction
    • muscle length does not change but muscle tension increases
    • -happens when pushing against an immovable object, like a wall.
  21. Twitch
    jerky response to a stimulus
  22. Tetany
    abnormal contraction of muscle caused by “rapid fire” impulses.
  23. voluntary muscles
    -skeletal muscles

    -striated- have light and dark bands of fiber
  24. involuntary muscle
    • -smooth- makes up most organs of body
    • -cardiac- in heart

    -appears striated under microscope
  25. Contractility
    ability of a muscle to shorten and thicken upon stimulus.
  26. Extensibility
    The ability of a muscle to stretch
  27. Elasticity
    ability of a muscle to return to its original length after stretching
  28. Irritability
    ability of a muscle to respond to stimulation.
  29. Prime mover
    muscle responsible for movement when a group of muscles is contracting at the same time
  30. Fixator
    specialized synergists that stabilize the nonmoving part of a prime mover
  31. Origin
    • where a muscle begins or is attached to a bone.
    • -a fixed attachment
  32. Insertion
    • where a muscle ends
    • -more movable.
  33. Deltoid
    shoulder muscle that looks like an upside down delta.
  34. Abductor
    muscle that moves a bone away from midline.
  35. Adductor
    muscle that moves a bone toward the midline.
  36. Levator
    muscle that lifts a bone.
  37. Depressor
    muscle that lowers a bone
  38. Flexor
    muscle that bends a joint
  39. Extensor
    muscle that straightens a joint
  40. Rotator
    muscle that moves a joint on its axis
  41. Sphincter
    a ringlike muscle that closes an opening
  42. Strain
    overstretching or tearing of muscle fibers
  43. Sprain
    stretching or tearing of a ligament or joint
  44. Myalgia
    muscle pain
  45. Hernia
    when a visceral organ bulges through a weakness in a muscular wall.
  46. Torticollis (wryneck)
    causes head to tilt to affected side
Card Set
Anatomy Chapter 19 Mucular system
Mucular system