Tasks 6-7

6. Effects of Acetylcholine in the presence of atropine

  1. measure the heart rate before and at 20s after the application of acetylcholine against a background of atropine. Record control heart rate, heart rate after atropine alone and heart rate after atropine and acetylcholine.
  2. explain the action of atropine. At what type of receptor on cardiac muscle cells does atropine act?

7. Effects of Temperature
  1. measure the heart rate changes before and after application of Ringer's solution at different temperatures: 0°C; 20°C; 40°C.
  2. explain the effects of temperature on the heart rate.
  3. define the term poikilothermic.