Chapter 17.4, Problem 8AYLO

Summary Introduction

To discuss:

The location of hormone receptors in the target cells and differences between hydrophilic and hydrophobic hormone receptor systems.                      

Introduction:

Hormones are chemical messengers secreted by the endocrine glands or neurosecretory cells into the extracellular fluids. The secreted hormones reach the target cells through the bloodstream, and they stimulate response of other tissues or cells. Hormones bind only to specific cells based on their corresponding receptors present on the cells. Hormones act through chemical signals. They regulate growth, development, blood pressure, metabolism, fluid concentration, and maintain homeostasis in the body. Both positive feedback and negative feedback mechanisms may regulate hormone pathways. Positive feedback amplifies the stimulus, whereas negative feedback dampens the stimulus and stops the pathway.