Final Part 2 skeletal amd cardiac muscle and neurotoxins

  1. How would the loss of acetylecholinesterase from the motor end plate affect skeletal muscle?

  2. Which of the following statements is correct in comparing cardiac autorythmic and skeletal muscle cells?

    D. ?
  3. increases in venous return to the right atria trigger a reflex known as the...
    Bainbridge complex
  4. Besides the size of muscle fibers what else will determine the amount of force of a skeletal muscle contraction?
    • Frequency of a stimulus
    • Length of a muscle cell (80% to 120%)
    • Number of fibers involved
  5. At rest, active sites on the actin of skeletal muscle tissue are physically blocked by...

  6. At the peak of a action potential in a neuron,

  7. increases in Na+ permeability in autorythmic cells would have what effect on cardiac function?

  8. Increases in blood pressure will have what affect on heart rate?
    ???Increase heart rate??? Since there's less cardiac output the heart compensates???
  9. The action potential is conducted down into a skeletal muscle fiber by...

    B. I believe
  10. During peak (maximal) levels of physical activity which metabolic pathway within skeletal muscle tissue is skeletal muscle tissue depending on for the production of most of its ATP and how many net ATP are produced and why this pathway?
    No or little O2 available so it breaks down a glucose and that makes 2 pyruvic acid creating 2 ATP.
  11. During a resting heart rate the normal EDV would be____mLs; the ESV would be _______mls.
  12. What does the duration of a muscle contraction depend on?
    • The amount of Ca+ in the sarcoplasma
    • If there is ATP available
    • Duration of neural stimulus
  13. Specifically how does the neurotoxin batrachotoxin interfere with the formation of action potentials?
  14. Name the neurotransmitter that causes a decrease in heart rates and identify which autonomic nervous system this neurotransmitter comes from?
    parasympathetic nervous system, ACh
  15. What causes the Frank- Starling principle to take place?
    When the ventricle is filled up with more then usual amount of blood, this causes the ventricle to stretch so the actin and myosin line up more efficiently, causing a stronger contraction in the ventricle. The heart can only stretch so far before the pericardial sac wont let it anymore.
  16. Creatine phosphate in skeletal muscle tissue gets its phosphate from what molecule?
    • ATP
    • Creatine phosphate + ADP = ATP + creatine
  17. What is responsible for the plateau seen in the action potential of cardiac contractile tissue?

  18. What part of the brain is involved in altering the heart rate?

  19. All of the following are true of graded potentials except they:

  20. Which of the following would increase heart rate?

  21. Acetylcholine slows the heart rate because it..

  22. Each of the following factors will increase cardiac output, except...

  23. Stroke volume depends on

  24. When a muscle is stimulated repeatedly at a high right, the amount of tension gradually increases to a steady maximum tension. This is called...

    B. ??
  25. Name the neurotransmitter released from the parasympathetic nervous system onto the heart and the specific receptor this neurotransmitter will bind with in the heart tissue?
    ACh and the receptor is muscerinic
  26. Under normal healthy conditions when a skeletal muscle is in peak level of activity the mitochondria are not generating their maximal number of ATP because...

  27. During an electrocardiogram which part is associated with the ventricles depolarizing?

  28. Which of the following would decrease heart rate?
    A. increased levels of norepinephrine
    B. faster repolarization of the SA node's membrane potential
    C. increased sympathetic stimulation of SA node
    decreased parasympathetic stimulation of the SA node
    E. none of the above
  29. in cardiac contractile cells, the very first portion of the repolarization phase of the action potential is the result of...

  30. Each skeletal muscle cell has how many neuromuscular junctions?
    1 neuromuscular junction per muscle cell
  31. During a normal heart rate of 72 beats per minute we find there is _____ mL blood in the left ventricle at the start of each ventrivular contraction and at the end of the contraction there is ____ mL of blood.
    135 and 65
  32. The most important factor in increasing the intracellular concentration of Ca+ in a skeletal muscle fiber is..

  33. Two parts to this question. When autorythmic cells have a lower then notmal amount of extracellular K+ this creats a condition known as ______ (fill in the blank) and this would cause...
    A. the cells to become hypopolarized
    B. a change in repolarization rates of autorythmic cells.
    C. no affect because it would be offset by a decrease of Ca2+ entering the cell
    D. the cells to become hyperpolarized.
    hypokalemia and D.
  34. During moderate levels of skeletal muscle activity what are the different substances with the mitochondria using to generate ATP? Think carefully
    The mitochondria is using O2 and the fatty acids from the blood stream and mitochondria is also using pyruvic acid that was a break down from glucose (that gave 2 ATP in the process of breaking glucose into pyruvic acid) the pryuvic once in the mitochondria create 32ATP
  35. Cardiac output is increased by...

  36. During a skeletal muscle contraction which of the following actually changes in size?

  37. Describe a general way what is taking place with each of the different component of a skeletal muscle twitch.
    The latent period before it can start the twitch is when the AP is going down the T tubules and lets ca+ out. The Ca+ binds to troponin. When the latent phase is over the actual twitch begins and the myosin heads attach to the actin do the power stroke and then relax and it's back to normal again.
  38. If the signal from the SA node to the AV node is prevented...

  39. Assume normal levels of k+ inside and outside of the cell for this question. If the membrane of the SA nodes cells has significantly fewer leaky K+ channels, the...

  40. List 2 different types of factors that can lead to an increase in stroke volume.
    If more blood goes into the atria because of increased activity (bainbridge) then the heart rate will increase and that will increase the EDV sense more blood is coming to the ventricles the heart will sense more blood is coming to the ventricles, the heart will contract stronger (Frank Starling) because the actin and myosin are lined up better. More blood would be pumped out causing decreased ESV
  41. When the following best describes the direct (immediate) cause of an end-plate potential forming on skeletal muscle cell?

  42. What is responsible for the plateau portion of the cardiac contraction action potential?
    The Ca@ voltage gates open Ca+ comes in simultaneously the K+ voltage gates are already open letting K+ out of the cell. The Ca+ and the K= reach a sort of equilibrium until the ca+ voltage gates finally close then the cell finishes repolarization.
  43. What causes the atrial reflex to take place and how does the heart respond because of this reflex?
    The atrial reflex also called the Bainbridge reflex happens when the atria stretch more then normal because of increased blood flow. The stretch receptors in the atria tell the medulla, the medulla tells the heart to increase through the sympathetic epinephrine release.
  44. if the connection between the vagus nerve and the heart is cut, which of these changes will occur?

  45. Describe what is taking place in the ventricle during isovolumic contraction phase.
    The heart is filled with the 135 mL of blood so all the valves close and the ventricle contracts which increases the pressure in the chamber but the volume stays the same.
  46. List the different myogenic (autorythmic) cardiac cells that are capable of spontaneously generating action potentials and give their approximate rates of producing action potentials.
    • Sa Node- 80-100 AP/min
    • AV node- 40-60 AP/min
    • Perkjine fibers- 20 AP/min
  47. Draw a diaghram demonstrating the action potential seen in a autorythmic cell. for each segment of the AP indicate the ions involved and their direction.
    make sure the sides are labels that you label threshold! and you indicated the ions going in and out.
  48. A drug that blocks the neurotransmitter receptors located on a skeletal muscle cell

  49. Provide 1 structural explanation for why the electrical impulse (from the SA) slows down as it reaches the AV node.
    • 1) as the fibers from the SA node reach the AV node they get smaller and smaller in diameter the slower the impulse (type C vs. type A fibers)
    • 2) There are less gap junctions
  50. Which if the following statements is correct?

  51. In an concentric contraction,

  52. Choose the best answer that completes this statement. Drugs that block the beta-one andrenergic receptors on the heart will...

  53. List 3 major factors that will determine the duration of a single muscle contraction
    • Duration of a stimulus
    • Number of Ca+ in the sarcoplasma outside the SR
    • A TP is available.
    • (DNA)
  54. In terms of cardiac reflexes what do we call the cells that are located in the right atrium and also the aorta that monitor the blood pressure there? and how does the heart rate respond if there is an increase in the blood pressure?
    These are called baroreceptors and the slow the heart down
  55. Briefly but specifically identify how Butulinum toxins and BTX toxins alter the functioning of a neuron.
    • Botulinum stops the neuron from preforming exocytosis so the neurotransmitters wouldn't be able to leave the cell, causing placcid paralyze.
    • BTX opens and keeps the voltage gated Na+ from closing so you can stop making AP's causing Flaccid paralyze.
  56. Which of the following would increase heart rate?

  57. During a electrocardiogram which part is associated with the atria depolarizing?

  58. If the signal from the SA node to the AV node is prevented...

  59. At peak levels of skeletal muscle activity the ATP used in muscle contraction comes from...

    C. (creates 2 ATP without O2)
  60. What is a responsible for a end plate potential becoming a action potential in a skeletal muscle cell?

  61. In a resting skeletal muscle

Card Set
Final Part 2 skeletal amd cardiac muscle and neurotoxins
The final questions that have to do with skeletal and cardiac muscle