The primary objectives of this worksheet are to report and explain the results of experiments involving smooth muscle contraction in the rat intestine.
 

1. (Part I) Attach a section of the Physiograph record showing baseline contractile activity of the
     intestinal smooth muscle.
 
 
 
 
 
 
 
 
 
 
 
 
 
 

2. (Part II) Describe the effects of each of the following treatments on smooth muscle contraction
     in your preparation:

     a. Epinephrine.
 
 
 
 
 

     b. Epi + Propranolol (beta-blocker).
 
 
 
 
 

     c. Epi + Tolazoline (alpha-blocker).
 
 
 
 
 

 3. (Part II) What is your conclusion concerning the relative abundance of alpha- and
     beta-adrenergic receptors in intestinal smooth muscle?
 
 
 
 
 
 
 
 
 
 
 

4. (Part III) Draw a dose-response curve showing the effects of acetylcholine on intestinal smooth
     muscle in the absence and presence of atropine.
 

5. (Part IV) In the final step of the experiment, EDTA was added to remove free calcium ions from
     the tissue bath.

     a. What was the effect of EDTA on intestinal smooth muscle?
 
 
 
 

     b. How could this effect be reversed?