What is the pituitary and what role does it have?

The pituitary (or the hypophysis) is a gland located at the base of the encephalon. It's composed of three lobes: the anterior lobe, the intermediate lobe and the posterior lobe. These lobes produce hormones that either affect the activity of other glands (tropic hormones) or of other parts of the body. For example, the anterior lobe produces the tropic hormone named Thyroid-stimulating hormone (TSH) which influences the activity and the growth of the thyroid, another gland. A non-tropic hormone produced by the anterior lobe is the growth hormone (or somatotropin, STH), which stimulates growth, cell reproduction and regeneration.