Kidney and adrenal gland. Artwork of the human kidney with the adrenal gland and ureter. The kidney (red) is one of a pair of organs that form urine by filtering out waste products from the blood. The urine travels down the ureter (long, yellow) to the bladder (unseen). On the kidney's top surface is the adrenal gland (yellow). This endocrine gland secretes a variety of hormones. These include adrenaline (epinephrine), the body's stress hormone. Adrenaline increases heart rate, breathing and metabolism to prepare the body for fright, flight or fight". The adrenals also produce corticosteroid hormones which affect carbohydrate metabolism and the sex glands."