About Lesson
Introduction
- Different types of endocrine glands are found in fishes; such as-
- The pituitary gland or Hypophysis
- Thyroid Gland
- Adrenal gland
- Corpuscles of Stannius
- Ultimobranchial Glands
- Urohypophysis
- Pancreatic islets
- Pineal gland
- Chemically, hormones can be divided into three classes:
(I) Steroid hormones (testosterone & estradiol)
(II) Protein (peptide) hormones (e.g., insulin) and peptide hormones are secreted by hypophysis, thyroid, internal tissue and pancreatic tissue.
(Ill) The amino acid analogues are norepinephrine and epinephrine, collectively called catecholamines.