Chapter 17, Problem 16TYR

Summary Introduction

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,and they act through chemical signals. They regulate growth, development, blood pressure, metabolism, fluid concentration, and 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.