preview

Frog Heart Lab, Animal Physiology

Better Essays

Chemical and Environmental Effects on the Heart
Introduction
The heart is the centerpiece of the circulatory system, its muscular contractions allow for the timely delivery of essential gases and nutrients to virtually all cells of the body. The pressure created by the heart also plays a vital role in eliminating wastes through organs such as the kidney, thus the heart delivers and helps maintain nutrient and waste composition throughout the body. The heart, like all muscle cells, releases ionic calcium when stimulated which binds to troponin which in turn causes tropomyosin to uncover the myosin-actin binding sites on the muscle. Temperature has effects on the metabolism and activity of all cells. Warmer temperatures increase the …show more content…

Following exposure to epinephrine, the heart was allowed to return to its resting state determined in procedure 1. This same procedure was repeated with the following chemicals: 1) Acetylcholine, 2) Atropine, 3) Calcium solution, 4) Nicotine solution, and 5) Caffeine solution.
Procedure 4: The Refractory Period of the Heart
Resting heart contractions were recorded for thirty seconds until the heart rate was less than 60 beats per minute. A stimulator electrode to be used was set to the following states: Amplitude of 4.00 Volts, a stimulus delay of 50ms, stimulus duration of 10ms, a frequency of 1.0Hz, and a pulse number of 30. The electrode was then placed in direct contact with the heart for 30 seconds at which time the data was observed and recorded.
Procedure 5: Effects of a Ligature on the Heart
A 30cm piece of thread was placed around the heart at the Atrioventricular groove (AV groove) and tied in a knot but left loose so as to not interrupt the normal function of the heart. The heart was allowed to beat for about 15 seconds with no pressure. After 15 seconds the knot was slowly tightened while taking care to stay on the AV groove while tightening. Data was observed and recorded.
Results
Procedure 1: The Heart Rate
This experiment was carried out as noted about in Procedure 1. The resting heart rate was established and used as a baseline value from which to compare all future deviations. While data could

Get Access