Saliva: It is secreted by the salivary glands,Sweat achieved by the water-rich secretion of the eccrine glands. Epinephrine: It is also known as adrenaline is a hormone and a neurotransmitter. Bile: It is a bitter-tasting dark green to yellowish brown fluid produced by the liver that aids the process of digestion of lipids in the small intestine. Bile is the odd one among all four as it is secreted by liver, while others are secreted by glands.