Pituitary gland. Coloured scanning electron micrograph (SEM) of a rat's pituitary gland. This resin cast shows the blood vessels (centre) that surround the gland. The pituitary (hypophysis) is the master endocrine gland, which hangs just below the centre of the brain of all vertebrates. It secrets two functional groups of hormones, those that control the secretions of other glands and those that stimulate the activity of other tissues. Examples include: growth hormone, thyroid-stimulating hormone (TSH), follicle- stimulating hormone (FSH) and luteinizing hormone(LH). Magnification: x38 at 6x7cm size.