Chapter 13, Problem 1P

Summary Introduction

To define:

The term hormone.

Introduction:

Hormone is a chemical substance which is secreted by the body cells. They are regulatory chemical substance that plays an important role in the growth and development of the body. The body cells produce the hormones that are transported to the other cells through blood or induce the organs to its action.

Explanation of Solution

The organs of endocrine system release chemical signal as hormones. A hormone is released by the organ system when it receives an internal stimulus through brain. The released hormone then reaches the target site by travelling through the cardiovascular system. Then the target organ responds to this signal. The endocrine system is responsible for the regulation of body metabolism and growth.

The hormones are of two types:peptide hormone and steroid hormone. The peptide hormones are made up of proteins and amino acids, and the steroid hormones are derived from cholesterol.

The hormones are different to the neurotransmitters. A neurotransmitter is a chemical released by the nerve cells in response to external stimuli. A hormone is a chemical released by the different body organs in response to the internal stimuli. The released hormones reach to the organs through blood that induces the organs to its action.

Conclusion

The hormone is a chemical released by the different body organs in response to the stimuli. The released hormone then reaches the target site by travelling through the cardiovascular system. Then the target organ then respond to this signal.