Digestive glands:

• Salivary glands
• Gastric glands 
• liver
• Pancreas
•  Intestinal gland

 

1) Salivary gland:

• Parotid gland → Largest salivary gland lies on sides of face, its viral infection causes swelling & pain disease called mumps, also called stensen’s duct.  
• Sub-lingual glands → Lies under the tongue another name is duct of rivinus.
• Sub-maxillary gland → Lies at angle of lower jaw also called wharton’s duct.

Secretions of salivary gland:  It secrets a viscous fluid called saliva which contain water, salt, mucin & ptylin (salivary amylase enzyme).  1 – 1.5 liter saliva is secreted every day. This enzyme in saliva is not present in herbivores.

Functions of saliva:

• Neutralize acidity in buccal cavity
•  kill bacteria
•  Moistons buccal cavity
• Help in digestion.

 

2) Gastric glands:

Microscopic glands in the wall of stomach, have 3 types of cells.

• Peptic (zymogen): Produce enzymes zymogens- (all inactive) pepsinogen & prorenin.
• Oxyntic cells: Secrete HCL.
•  Mucus cells: Add mucus to these all secretions.

These all secretions combinally known as gastric juice.  2 – 3 litre gastric juice secreted per day.

3) Liver:

It is largest gland of body forms (1/40^th) weight of body consist 2 main lobes.

• Large right lobe
• Smaller left lobe

A thin walled, sac like lobe called gall bladder is present is the right lobe. Gall bladder stores bile. Bile is yellowish – green fluid produced by bile duct. Bile dust passes down-ward and joined by pancreatic duct forming a common hepato-pancreatic duct. It opens into duodenum regulated by sphincter of oddi to prevent backflow of food. Bile has no enzymes, PH is – 8 (basic)  and has salts, sodium glycocholate & sodium taurocholate & pigments bilirubin & biliverdin.

4) Pancreas:

It is elongated, yellowish gland.

• Pancreas act as an endocrine as well as exocrine organ.
•  Exocrine tissue secretes pancreatic juice (PH – 8.5) release by pancreatic duct. Pancreatic juice contains sodium bicarbonate, 3 pro-enzymes (zymogen) inactive enzymes namely,  tripsinogen,  chymotrypsinogen  and pro-carboxy- peptidases, & other enzymes like  pancreatic amylase, nucleases, lipase.
• And its endocrine role is that it secretes 4 hormones: Insulin,  glycagon,  somatostatin, pancreatic polypeptide.

5) Intestinal glands:

They are small & many in number lies in wall of small intestine.

(1) Crypts of lieberkuhn:- Occurs between villi secrete enzymes & mucus.

(2) Brunner’s gland:- Present in deodenum part of small intestine, secrete alkaline watery fluids, a little enzymes & mucus.

 

Intestinal juice has a PH 8.3 (basic), and secreted 2-3 litre per day. It has many enzymes – amino & di-Peptidases, intestinal amylase, maltase, iso-matlase, limit dextrionase,  sucrase, lactase, intestinal lipase, nucleotidases. Nucleosidases, entero-kinase.