Discussion The purpose of this experiment was to determine the effects of nicoti
ID: 201564 • Letter: D
Question
Discussion The purpose of this experiment was to determine the effects of nicotine on peripheral blood flow and heart rate. In response to nicotine, blood flow decreased dramatically for both volunteers. These results on blood flow were expected after the smoking a cigarette. Nicotine, similar to caffeine, is a stimulant that should increase blood pressure. To do this the vessels need L to constrict decreasing blood flow. With this in mind, we hypothesized that the blood flow would decrease as it did. These results were similar to a recent study that found that smoking either a light or regular cigarette decreased the flow mediated dilation (1) With less dilation there was also less blood flow after the body took in the nicotine. The most likely mechanism for this decrease in blood flow was hormonal. When the nicotine was inhaled by smoking, it went into the lungs and absorbed directly into the blood stream The nicotine acted as a stimulus that traveled to the brain, where it activated the medulla. There the medulla most likely seat hormones to the smooth muscle in the blood vessels These hormones constricted the vessels which resulted in a decrease in blood now In addition to the change in blood flow, the change in heart rate was also determined. In response to nicotine, the average heart rate of both volunteers increased slightly This result was unexpected from our group. We hypothesized that heart rate would dramatically increase because nicotine is a well- known stinmlant, which normaly noticeably increases beart rate Even though the change in heart rate was not as noticeable as expected, nicotine effect on the body. The likely mechanism for this increase in heart rate is also hormonal. The nicotine entered the blood stream and traveled to the hypothalamus in the brain. still did have an There the brain
Explanation / Answer
To enrich your discussion you can look in a physiology book about nicotinic receptors. I can roughly tell you that these receptors are found throughout the brain or neural tissue, however the distribution of these receptors is heterogeneous. Specifically, these neural receptors can be classified into two groups depending on the inhibitor with which they are blocked. These receptors when activated allow the passage of calcium and sodium ions that depolarize the membrane and allow to stimulate secretion.
They can potentiate and facilitate the secretion of acetylcholine, or glutamate or noradrenaline. Nicotine also promotes the release of dopamine in the striated and cardiac muscle (aslo searh for dopaminergic effect) and one of the mechanisms to explain tobacco addiction is based on the release of dopamine when inhaling nicotine from cigarettes. Now keep in mind that if there is release of acetylcholine this can travel to your receptor in the neuron, there is a vagus nerve stimulation and this promotes the decrease in the number of heart beats. Do not forget to consider that if your companions are habitual smokers they will have an effect of pharmacological resistance (that is, they will need more nicotine to be able to achieve the same effect).
In the case of putting your hand in cold water, you can activate other nerves that lead to similar responses, remember that as mammals we have a certain predisposition to hibernate, during the winter the oranisms that hibernate have a very low metabolic rate (including the number of heartbeat) when exposed to that cold that response is stimulated to prepare to hibernate.