8. Study the homeostatic scheme below:
Excess
Less hormone A
С
Normal concentration of
sodium ions in the blood
Normal concentration of
sodium lons in the blood
C
Deficiency
Release of hormone A
[
i Further deficiency
(1mk)
(a) Identify the hormone labeled A
(b) Name the site of action of hormone A
(1 mk)
6
(c) Identify the feedback labeled D
(1mk)
Answers
Answer:
Hormones have a wide range of effects and modulate many different body processes. The key regulatory processes that will be examined here are those affecting the excretory system, the reproductive system, metabolism, blood calcium concentrations, growth, and the stress response.
Hormonal Regulation of the Excretory System
Maintaining a proper water balance in the body is important to avoid dehydration or over-hydration (hyponatremia). The water concentration of the body is monitored by osmoreceptors in the hypothalamus, which detect the concentration of electrolytes in the extracellular fluid. The concentration of electrolytes in the blood rises when there is water loss caused by excessive perspiration, inadequate water intake, or low blood volume due to blood loss