Hormones are the body’s chemical messengers and are part of the endocrine system. Endocrine glands make hormones, which travel through the bloodstream to tissues and organs, and control most of our body’s major systems.
Many hormones are secreted by special glands, such as thyroid hormone produced by the thyroid gland.
MAJOR TYPES OF HORMONE
They are hormones made from lipids. They send messages near the cells that make the hormones.
Amino acid derived hormones
These are hormones that one nerve cell sends to another. Most of them are neurotransmitters.
Peptides, polypeptides and protein hormones
Examples of such hormones include growth hormones and insulin
These hormones are derived from cholesterol. They include testosterone and estradiol.
CLASSIFICATION OF HORMONES
Hormones are classified into five different categories. The categories include:
- According to chemical nature
- According to mechanism of action
- According to nature of action
- According to the effect and
- According to their stimulation of Endocrine glands.