Endocrinology - Study of endocrine glands, hormones and their effects.
Thomas Addison - Father of endocrinology. Described hormonal disease in 1855 known after his name as Addison's disease.
Berthold - Laid foundation of endocrinology.
Huxley called hormones as chemical messengers.
Claude Bernard called hormones a internal secretions.
Gudernatsch studied effect of thyroxine on metamorphosis of tadpole larva of frog.
Kendall prepared crystals of thyroxine.
Banting and Best isolated insulin.
Kimbell and Murlin isolated glucagon.
Karlson and Butendant coined the term pheromones.
Origin - Endocrine glands are mostly endodermal. Adrenal gland has ectodermal medulla and mesodermal cortex. In pituitary gland neurohypophysis is ectodermal while the anterior and middle lobes are endodermal. Pineal gland and hypothalamus are ectodermal.