Explain the types of hormones depending upon their origin.

On the basis of their chemical nature, hormones are divided into four groups  :

1. Amino acid derivatives : These hormones are formed from amino acids e.g. epinephrine, norepinephrine etc.

2. Peptide derivatives : These are of derived from peptide, polypeptide and proteins e.g. insulin, glucagon, pituitary, hypothalamic hormones etc

3. Iodothryonines derivatives : e.g. thyroid hormones.

4. Steroid hormones : These are derived from steroids just as cholesterol e.g. testosterone, progestrone etc.