Sweat glands are glands in the skin that produce a fluid called sweat. The main role of a sweat gland is thermoregulation. There are two types of sweat glands: Apocrine and Eccrine Sweat Glands.
Eccrine sweat glands are found all over the human body. There are between several million eccrine sweat glands and they are stimulated by the cholinergic sympathetic nervous system in which acetyl choline is the neurotransmitter that triggers the secretion sweat. Eccrine glands secrete sodium ions, chloride ions, lactate and water.
Apocrine sweat glands are usually found in the armpit. They are larger than eccrine glands and there are fewer of them; only around 100,00. They secrete lipids and carbohydrates.
A technique which can be used to study sweat secretion is by attaching a small plastic well to the skin and fill it with paraphrin oil as this will prevent the sweat from evaporating. Small droplets of sweat will begin to appear and these can be collected by fine capillary tubes to analyse the composition.