Hirudin Hirudin Hirudin is a naturally occurring peptide in the salivary glands of blood-sucking leeches (such as "Hirudo medicinalis") that has a blood anticoagulant property. This is fundamental for the leeches’ alimentary habit of hematophagy, since it keeps the blood flowing after the initial phlebotomy performed by the worm on the host’s skin. During his years in Birmingham and Edinburgh, John Berry Haycraft had been actively engaged in research and published papers on the coagulation of blood, and in 1884, he discovered that the leech secreted a powerful anticoagulant, which he named hirudin, although it was not isolated until the 1950s,
Salivary gland of taste buds lining the sides of the papillae, and is important for dissolving the food particles to be tasted. Salivary glands are innervated, either directly or indirectly, by the parasympathetic and sympathetic arms of the autonomic nervous system. Parasympathetic stimulation evokes a copious flow of saliva. In contrast, sympathetic stimulation produces either a small flow, which is rich in protein, or no flow at all. The gland is internally divided into lobules. Blood vessels and nerves enter the glands at the hilum and gradually branch out into the lobules. Secretory cells are found in a group, or acinus (plural,