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Physioex 8.0 Exercise 6 Activities 1, 2, 3,4
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I need help with these activities. My assignment is due on sunday and I wont have access to a comptuer all weekend so I need them ASAP!!!! HELP ME

Electrical Stimulation
Activity 1:  Direct Heart Stimulation

1. Did you see any change in the trace?  There was no change in the trace after selecting Single Stimulus.
2. Why or why not?  This is due to
3. Did you see any change in the trace?
4. Why or why not?  
5. Describe the change you see in the trace.  How does it differ from the baseline trace?  
6. What effect do the repeated stimuli have on the heartbeat trace? Describe the trace.
7. What part of the trace shows the refractory period?  
8. Does summation occur?  
9. Why is it important that summation not occur in heart muscle?  

Activity 2:  Vagus Nerve Stimulation

1. Describe the effect of the vagus nerve stimulation on the heartbeat.
2. Soon after you applied the stimuli, did the heart rate increase or decrease?  
3. Why?  
4. How do the sympathetic and parasympathetic nervous systems work together to regulate heart rate?  
5. Complete the following: As heart rate decreases, cardiac output _______ (assuming stroke volume remains the same).  As heart rate increases, cardiac output ________ (assuming stroke volume remains the same).
6. What does this tell you about the parasympathetic nervous system in relation to the sympathetic nervous system and hormones?  

Modifiers of Heart Rate
Activity 3:  Effect of Epinephrine

1. What was the effect of epinephrine on heart rate?  
2. Does this effect mimic the effect of the sympathetic nervous system or that of the parasympathetic nervous system?  
3. What is the heart rate when the status window reads Heart Rate Stable?  

Activity 4:  Effect of Pilocarpine
1. What was the effect of pilocarpine on heart rate?  
2. What is the heart rate when the status window reads Heart Rate Stable?  

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Physioex 8.0 Exercise 6 Activities 1, 2, 3,4
3 years ago
Here is a similar assignment I had. It is Physioex 8 exercise 6:

Electrical Stimulation
Activity 1:  Direct Heart Stimulation

1.   Did you see any change in the trace?  No
2.   Why or why not?  It needs more stimulation   
3.   Did you see any change in the trace? yes
4.   Why or why not?  the stimulation was doubled
5.   Describe the change you see in the trace.  How does it differ from the baseline trace?  It increased in comparison to the baseline trace
6.   What effect do the repeated stimuli have on the heartbeat trace? Describe the trace. The heartbeat trace showed a flat line then returned to normal and then flat lined again, it continued that pattern.
7.   What part of the trace shows the refractory period?  atrial contraction
8.   Does summation occur?  no
9.   Why is it important that summation not occur in heart muscle?  Heart muscle contractions would increase leading to a heart attack.

Activity 2:  Vagus Nerve Stimulation

1.   Describe the effect of the vagus nerve stimulation on the heartbeat. The vagus nerve stimulation caused the heartbeat to flat line and then to restart and return to normal.
2.   Soon after you applied the stimuli, did the heart rate increase or decrease?  Heart rate decreased.
3.   Why?  The cardiac muscle cells depolarize.
4.   How do the sympathetic and parasympathetic nervous systems work together to regulate heart rate?  Sympathetic neurons increase the heart rate while the parasympathetic neurons decrease the heart rate and the heart simultaneously receives both neurons signals.
5.   Complete the following: As heart rate decreases, cardiac output ____slows___ (assuming stroke volume remains the same).  As heart rate increases, cardiac output __speeds up______ (assuming stroke volume remains the same).
6.   What does this tell you about the parasympathetic nervous system in relation to the sympathetic nervous system and hormones?  That they are inversely proportionate to each other.

Modifiers of Heart Rate
Activity 3:  Effect of Epinephrine

1.   What was the effect of epinephrine on heart rate?  The Epinephrine increased the heart rate.
2.   Does this effect mimic the effect of the sympathetic nervous system or that of the parasympathetic nervous system?  The effect mimics the sympathetic nervous system.
3.   What is the heart rate when the status window reads Heart Rate Stable?  The heart rate is at 82 when the status window reads heart rate stable.

Activity 4:  Effect of Pilocarpine

1.   What was the effect of pilocarpine on heart rate?  The pilocarpine decreased the heart rate.
2.   What is the heart rate when the status window reads Heart Rate Stable?  The heart rate is at 47 when the status window reads heart rate stable.

 
Activity 5:  Effect of Atropine

1.   What was the effect of atropine on heart rate?  decreased the heart rate.
2.   What is the heart rate when the status window reads Heart Rate Stable?  The heart rate is at 73 when the status window reads heart rate stable.
3.   If you were to administer drops of pilocarpine to the heart and then administer atropine immediately afterward, what effect would you expect to see on the heart rate?  I would expect the heart rate to be about normal if I were to administer drops of pilocarpine and then administer atropine afterward.

Activity 6:  Effect of Digitalis

1.   What was the effect of digitalis on heart rate?  Digitalis decreased the heart rate.
2.   What is the heart rate when the status window reads Heart Rate Stable?  heart rate is at 41
3.   Why might digitalis be used on a patient with such a condition?  Digitalis might be used in a patient with Atrial Fibrillation because it slows the heart rate down when it beats faster than it needs to.

Activity 7:  Effect of Temperature

1.   What was the effect of temperature on the frog’s heart rate?  As the temperature gets colder the heart rate decreases and as the temperature gets hotter the heart rate increases.

Activity 8:  Effects of Ions

1.   What was the effect of calcium ions on heart rate?  heart rate decrease
2.   Why?  Calcium channels begin closing, reducing the flow of calcium into the cell.
3.   Where in a heart cell is calcium normally found?  on the outside of the heart cell.
4.   What was the effect of sodium ions on heart rate?  Sodium ions caused the heart rate to decrease
5.   Why?  The open sodium channels begin to inactivate, decreasing the flow of sodium ions into the cell and causing the membrane potential to fall slightly.
6.   Where in a heart cell is sodium normally found?  outside of the heart cell.
7.   What was the effect of potassium ions on heart rate? cause the heart rate to decrease
8.   Why?  Establishing the resting membrane potential and repolarization phase.
9.   Where in a heart cell is potassium normally found?   Inside the cardiac muscle cell


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