Digestive Glands

The Salivary Glands

Saliva is produced mainly by three pairs of salivary glands situated just outside the buccal cavity and opening their secretions into it: the parotids near the cheek, the sub-maxillary (sub-mandibular) glands in the lower jaw, and the sub-lingual glands below the tongue.

The Liver

The liver is the largest gland in the body, weighing roughly 1.2-1.5 kg in an adult. It sits in the abdominal cavity just below the diaphragm and is made up of two lobes. Its structural and functional units are hepatic lobules, in which liver (hepatic) cells are arranged in cord-like rows, each lobule wrapped in a thin connective-tissue covering called Glisson's capsule. The bile made by hepatic cells drains out through the hepatic ducts and is stored and concentrated in a small, muscular sac -- the gall bladder. Several small ducts from the liver converge and join the gall bladder's own duct (the cystic duct) to form the common hepatic duct, which continues on as the common bile duct.

The Pancreas

The pancreas is a compound gland, meaning it does two different jobs at once: it is both an exocrine gland, whose secretion (pancreatic juice) travels out through the pancreatic duct, and an endocrine gland, releasing the hormones insulin and glucagon directly into the blood. It lies cradled between the two limbs of the C-shaped duodenum.

Where the Two Ducts Meet …