Question

Many important endocrine control systems are arranged in a cascade of multiple steps.

a) Please briefly describe the spatial arrangement of the cascades in the human body in general terms.

b) Why do you think it is organized this way and not in a faster, one-step way?

Answer 1

Answer A -

Endocrine cascade pathway is a multistep pathway in which one hormone stimulate the other gland to release its hormone and this hormone in turn stimulate other gland to release its hormone. Thus endocrine cascade pathway is a interaction between the various glands by release of respective hormones and which lead to activation and release of the final hormone.

This can be understood by taking a example of thyroid hormone release.

Firstly, hypothalamus release TRH (thyrotropin releasing hormone) which stimulate anterior pituitary to release TSH (thyroid simulating hormone) . Now this TSH finally reach thyroid gland and cause release of T3 and T4 hormone.

In general, the cascade pathway start from hypothalamus then to pituitary and finally into target gland.

Answer B-

This cascade is a multi step process not a single step because having more steps in between gives more flexibility in regulation and control of hormone release at various level. In single step, regulation is very restricted and solitary.

Also ,if there is any defect in the single step pathway, the whole pathway will be affected. But multi-step process has an advantage that defect at any level will not completely stop the pathway.