The crypts of Lieberkuhn are simple, tubular glands which occur throughout the small intestine between the villi and secrete enzymes as well as mucus. The crypts have two types of cells at their base:
(a) Paneth cells : They are found particularly in the duodenum, in the bottom of crypts of. Lieberkuhn. These cells are rich in zinc and ยท contain acidophilic granules. They probably secrete lysozyme.
(b) Argentaffin cells: They are also known as entero-chromaffin cells and are fairly common in duodenum, located among epithelial cells lining the crypts of Lieberkuhn. Argentaffin cells secrete secretin hormone and 5-hydroxytryptamine (5-HT).