Peptide hormone growth hormone, which acts on bone, muscle, and the liver. The posterior pituitary gland secretes antidiuretic hormone, also called vasopressin, and oxytocin. The parathyroid gland secretes parathyroid hormone, the main hormone responsible for regulating serum calcium and phosphorus levels. Peptide hormones are also produced by many different organs and tissues, including the heart (atrial-natriuretic peptide (ANP) or atrial natriuretic factor (ANF)) and pancreas (glucagon, insulin and somatostatin), the gastrointestinal tract (cholecystokinin, gastrin), and adipose tissue stores (leptin). Peptide hormone Peptide hormones or protein hormones are hormones whose molecules are peptides or proteins, respectively. The latter have longer amino acid chain
Adrenal gland oriented bundles. The adrenal glands may not develop at all, or may be fused in the midline behind the aorta. These are associated with other congenital abnormalities, such as failure of the kidneys to develop, or fused kidneys. The gland may develop with a partial or complete absence of the cortex, or may develop in an unusual location. The adrenal gland secretes a number of different hormones which are metabolised by enzymes either within the gland or in other parts of the body. These hormones are involved in a number of essential biological functions. Corticosteroids are a group of steroid