Molecular Mechanism of Hormone Action (With Diagram) | Chordata | Zoology
The hormones are released in very small quantities, yet they cause wide spread responses in cells or tissues all over the body. These responses can be quite specific and selective in different cells. All vertebrate hormones belong to one of the four chemical groups: (i) Hormones such as adrenaline and thyroid hormone are small molecules derived from amino acid tyrosine. [...]