Effects of Temperature and Norepinephrine and Acetylcholine on Heart Rate

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Discussion paragraph for Aim 1: effect of temperature on heart rate (ectothermic regulation) [one peer reviewed journal citations].
Heart rate increased with warm solution; Decreased with cold ringer’s solution
Frogs are amphibians which are animals that modulate their temperature through ectothermic regulation. This means that these animals rely on the surroundings in order to raise the temperature of their bodies. In the wild, ectotherms depend on sunlight, or other external sources of heat such as a heated rock surface, or other areas that have been exposed to the heat of the sun. In the data gathered from the experiment, it can be observed that the frog’s heart rate increased with a warm solution, while it decreased with a cold solution. This lab experiment exhibited that the surrounding environment of a frog affects their metabolic operations, which includes their heart rate, given that they are poikilotherms(Barcroft, and Izquierdo). It was hypothesized that a decreased heart rate would result from decreasing the temperature that the frog is surrounded by. From the data, it can be inferred that temperature plays a huge role in the frog’s metabolism. As the temperature increases, the frog’s body works harder to regulate and balance its temperature which is why the frog’s heart rate increases. Increased heart rate means that the frog is continually pumping blood to its extremities wherein the process of ectothermal regulation happens, as it balances with the external environment.
Discussion paragraph for Aim 2: effect of stretch on contractile-force (Frank-Starling Law) [one peer reviewed journal citations].
Increase in heart contractile force → higher mean heart rate
Frank-Starling law: the greater the stretch at the end of diastole, the greater the strength of the subsequent ventricular contraction
In the experiment, it can be observed that an increase in the heart contractile force has a direct relationship with the frog’s heart rate. Going back to the physiology of a frog’s heat, we see that it has three chambers, which are one ventricle and two atria. This means that the Frank Starling Law is apparent in the performance of a frog’s heart. The Frank-Starling law states that an increased stretch on the myocytes or cardiac muscle cells increased t...