The Cardiovascular System

1. Explain the events of the cardiac cycle. 

2. Define stroke volume and cardiac output.  Describe the factors that influence these variables. 

3. Explain how adjustments in stroke volume and cardiac output are coordinated at different levels of activity. 

4. Describe the effects of autonomic activity on heart function. 

5. Describe the effects of hormones, drugs, temperature, and changes in ion concentrations on the heart. 
 

Part A  Cut & Paste  

Without referring to your text, place the following terms associated with the cardiac cycle in the proper sequence. You will be provided a sheet of terms to cut and paste as appropriate. 

P wave 
QRS Complex 
T wave 
Aortic semilunar valve opens 
Aortic semilunar valve closes 
Bicuspid Valve Opens 
Bicuspid Valve Closes 
Ventricular Diastole 
Ventricular Systole 
Atrial Diastole 
Atrial Systole 
S1 "lubb" 
S2 "dupp" 
S3 
S4  
End Diastolic Volume (left ventricle) 
End Systolic Volume (left ventricle) 
 

  Present the different events in the right sequence to the instructor. 
 

Part B  Pressure, pressure ont he wall  

1. Describe the pressure changes that occur in the aorta and left ventricle that cause the aortic semilunar valve to open and close. 

2. Describe the pressure changes in the left atrium and left ventricle that occur to cause the bicuspid valve to open and close. 
 P wave 
 

  Submit your written response to the questions to the instructor. 

Part C  As Good As It Gets 

1. The following measurements were made on Helen Hunt and Jack Nicholson. The values recorded remained stable for 1 hour. 
 
Helen Hunt --  heart rate, 75 bpm; stroke volume, 60 ml 
Jack Nicholson -- heart rate, 90 bpm, stroke volume, 95 ml 
 
 Which person has the greater venous return? Why? 

 Which person has the longer ventricular filling time? Why? 

 
2. Billy Crystal is taking the medication verapamil, a drug that blocks the calcium channels in cardiac muscle cells. What effect would you expect this medication to have on Billy’ stroke volume? 
 
3. Robin Williams EKG recording shows a consistent pattern of two P waves followed by a normal QRS complex and T wave.  What is the cause of this abnormal wave pattern? 
 
4. Kim Basinger’s end-diastolic volume is 125 ml, and her end-systolic volume is 40 ml.  What is Kim’s stroke volume?  Show your work. 
 
5. Why is hypokalemia life threatening?  What is potassium’s effect on cardiac contraction? 
 
 

  Submit your written output to the instructor.