DIGESTIVE GLANDS

 The digestive glands associated with the alimentary canal include the salivary glands, the liver and the pancreas.

Salivary glands

• (Secretion of salivary gland is known as saliva)
• Saliva is mainly produced by three pairs of salivary glands, the parotid (cheek), the sub-maxillary / sub-mandibular (lower jaw) and the sub-lingual (below the tongue).
• These glands situated just outside the buccal cavity secrete salivary juice into the buccal cavity.

Liver

• Liver is the largest gland of the body.
• Its weighing about 1.2 to 1.5 kg in an adult human.
• It is situated in the abdominal cavity, just below the diaphragm and has two lobes.
• The hepatic lobules are the structural and functional units of liver.
• Hepatic lobules containing hepatic cells arranged in the form of cords.
• Each lobule is covered by a thin connective tissue sheath called the Glisson's capsule.

• The bile secreted by the hepatic cells passes through the hepatic ducts.
• Bile is stored and concentrated in a thin muscular sac called the gall bladder.
• The duct of gall bladder (cystic duct) along with the hepatic duct from the liver forms the common bile duct (Figure 16.6- NCERT 11 Biology book).
• The bile duct and the pancreatic duct open together into the duodenum as the common hepato - pancreatic duct
• Hepato-pancreatic duct is guarded by a sphincter called the sphincter of Oddi.

Pancreas

• The pancreas is a compound (both exocrine and endocrine) elongated organ.
• Pancreas situated between the limbs of the 'C' shaped duodenum.
• The exocrine portion secretes an alkaline pancreatic juice containing enzymes.
• The endocrine portion secretes hormones, insulin and glucagon.