Question

Write your hypothesis for the “Testing Temperature” portion of this experiment. Be sure to include how you think the decreased temperature will affect blood pressure and heart rate, and, why.

Write your hypothesis for the “Testing Body Position” portion of this experiment. Be sure to include how you think blood pressure and heart rate will vary when you sit versus when you stand.

Explain your results in terms of the endocrine system. Indicate how the endocrine system is involved in the physiological response to temperature and body position.

Which glands are most likely to be involved with the physiological response caused in this experiment? Which hormones are most likely to be involved?

Answer 1

HYPOTHESIS FOR TESTING TEMPERATURE: At low temperatures, blood vessels become narrower leading to a higher blood pressure. A high blood pressure leads to a low pulse, which means that the heart rate decreases. On the contrary, at high temperatures, blood dilates and blood vessels are wider, causing a low blood pressure. This allows more blood to be pumped by the heart, causing an increase in the heart rate.

HYPOTHESIS FOR TESTING BODY POSITION: Due to the effects of gravity, more blood flows down into the lower part of the body on standing leading to the blood pressure to decrease and an increase in the heart rate. On sitting, this effect reduces, leading to a higher blood pressure and a lower heart rate.

ROLE OF THE ENDOCRINE SYSTEM: The hormonal activity inside the body is very important in maintaining the temperature, blood pressure and heart rate. The hypothalamus is responsible for maintaining the internal homeostasis. So, it is responsible for increasing or decreasing the body temperature when required. Furthermore, a higher body temperature leads to a lower blood pressure and a higher heart rate and vice versa for low body temperature. Hence, the hypothalamus controls all these functions in the body.