Calcium levels in Mr. Gallariani's blood are dropping to dangerously low levels. The hormone PTH is released and soon blood calcium levels begin to rise. Shortly after, PTH release slows. Is this an example of a positive or negative feedback mechanism? What is the initial stimulus? What is the result?

Video transcript

Hello everyone and welcome to today's video. So, in response to a stressful situation, a hormone is released which stimulates the adrenal gland to release cortisol, cortisol levels in the blood stream are going to increase. And in turn, the hormone production is going to slow down. What type of feedback mechanism is this as answer choice. A we have positive feedback. B negative feedback, C neutral feedback and the none of the options is correct. Well, there are two main types of feedback that we need to worry about. In order to solve this question, we have positive and we have negative. Now, positive feedback is going to involve the reinforcement of the stimulus causing an increase in productivity. So an example of positive feedback is going to be childbirth in mammals and for example, blood clotting. Now negative feedback is going to be the opposite. It is going to contradict the stimulus in order to reduce its effect. Now, example of certain negative feedback mechanisms include blood body temperature and blood ph. Now in this question, we're told that cortisol levels in the blood stream increase and in turn, the hormone production is going to slow down this is the feedback mechanism that is occurring. So because we have these cortisol levels increasing and in turn, the stimulus that is creating cortisol is going to be slow down or is going to decrease. This is said to be negative feedback because it is slowing down or reducing the effects of the stimulus. So answer choice B negative feedback is going to be the final answer to this question. I really hope this helped you and I hope to see you on the next one.