Circulatory Case Study 1



Digitalis is also known as digoxin and digitoxin. It is a drug that strengthens the contractions of the heart muscle, slows the heart rate, and helps to eliminate fluid from the body tissues. It is sometimes used to treat congestive heart failure and to treat certain arrhythmias. It has been used in the treatment of heart conditions since its discovery in 1775. Its discovery is accredited to the Scottish doctor William Withering. One of his patients came to him with a very bad heart condition, and Dr. Withering did not have an effective treatment for him. The patient went to a local gypsy who gave him an herbal remedy, and the patient promptly got much better. Dr. Withering bargained with the gypsy who finally told him her secret. The active ingredient in the herbal remedy was the purple foxglove, Digitalis purpurea.


Questions and Answers

Answer the following questions in the fields below.


Question 1: Trace a drop of blood from the heart to the body and back to the heart.  


Question 2: Distinguish between arteries, veins and capillaries both functionally and structurally.  Describe the composition and functions of blood.


Question 3: How does digitalis strengthen heart contractions?


Question 4:  How does digitalis control irregular heart rhythms (arrhythmias)?



Question 5:  Which types of arrhythmias are treated with digitalis?



Question 6:  Should digitalis be taken only when the patient feels bad?



Question 7:  What are some symptoms of digitoxin overdose?


Adapted from: Human Physiology-from cells to systems by Lauralee Sherwood

Thomson/Brooks-Cole Publ. 5th edition 2004