Each day, about 9 liters of fluid enters the duodenum. Most chemical digestion takes place in the duodenum by chemicals secreted by the liver, pancreas and small intestine. The other two sections of the small intestine, the jejunum and the ileum, absorb food molecules by way of the villi directly into the blood stream.
Histamine is synthesised in the brain in the hypothalamus, in a specific area known as the tuberomamillary nucleus (TMN), where it acts as a signalling messenger (or neurotransmitter). The hypothalamus is the area of the brain that overseas the metabolic processes of the body found in the central nervous system.
1 Histamine is a chemical that is normally produced in the body and stored in allergic cells, such as mast cells and basophils. In people with allergies, histamine is released from these cells in a response to allergens.