What is the function of the antidiuretic hormone? Where is it made and which are the stimuli that enhance or decrease its secretion?

The antidiuretic hormone is secreted by the hypophysis (also called as pituitary) and it acts in the nephron tubules enhancing the resorption of water. When the body requires retaining water, for instance, in cases of blood loss and abrupt blood pressure lowering or in cases of abnormally high blood osmolarity, there is stimulus for ADH secretion.

When the body has an excess of water, as in cases of excessive ingestion or in abnormally low blood osmolarity, the secretion of ADH is blocked and the diuresis increases. ADH is also called as vasopressin since it enhances the blood volume and therefore heightens the blood pressure.