er than that of atropines. Caffeine and epinephrine both increase heart rate. Caffeine cause the concentration of cAMP to increase which duplicates the action of the hormone epinephrine (Mitchell). The reason being that cAMP is utilized as a second messenger. Cardiac Physiology 9These two drugs because of their severe similarity exhibit comparable ECG readings. Again, no noticeable difference is observed. Nicotine slows the heart rate down. The most likely is caused by nicotine binding to nicotinic receptors. This activates the parasympathetic neuron that causes a slowing of the heart rate. It ECG is most comparable to that of calcium and digitalis due to the effect of slowing heart rate. Another way of studying the heart is through careful auscultating. In this particular lab, the heart sounds were listened to. No difference was noted during the different breathing patterns. This could very well be the cause of an untrained ear and of low quality stethoscopes. These two are both necessary in order to correctly perform the experiment. Table II shows that there was not much of a fluctuation in blood pressure under the various conditions. This could have been caused by a lack of time given for each condition. Inadequate time does not allow the body to adjust to the given conditions thus skewing the results. There is however, a slight decrease in the blood pressure after five minutes of motionlessness. This was due to a decrease in activity that lowered the blood pressure. Pulse pressure remained constant throughout each condition. As hardening of the arteries sets in, this would be expected to increase. Lastly, pulse per minute exhibits a trend that is quite common. Reclining (relaxed) shows a pulse of 80. As the subject stands, blood rushes down to the feet. This causes the pulse to keep up in order to evenly distribute the blood. My results concur with that phenomenon. Also, in order to provide adequate oxyge...
