A hormone is a chemical messenger produced by a ductless gland which has its action at a distant target cell via a specific receptor.
- Lipid hormones, divided into:
Steroids are synthesised from cholesterol, and are released as they are produced (they are not stored). They are highly lipid soluble and act on cytoplasmic and intra-nucleic receptors.
Eicosanoids are formed from cell membrane phospholipid.
- Peptide hormones
Peptide hormones are store in granules and released by exocytosis. They are divided into:
- Monoamine derivatives
Derived from a single amino acid.
Stored in granules and act at membrane receptors.
- Chambers D, Huang C, Matthews G. Basic Physiology for Anaesthetists. Cambridge University Press. 2015.