[Biology Class Notes] on Gastric Gland Pdf for EXAM

The gastric glands are the tube-like, branched structures that are present at the inner lining of the stomach. These glands are the basic secretory unit of the digestive system and are composed of various cell components which perform certain specific functions. These glands originate at the opening of the stomach’s lumen, the gastric pits, which itself is present at the gastric mucosa of the stomach. The gastric pit has pale-staining mucous droplets due to the presence of mucous-secreting cells. The base consists of the isthmus and neck of the gland. The gastric glands are mostly known to be exocrine in nature and help in the synthesis and secretion of the gastric juices along with protective mucous.

Types of Gastric Glands

There are various types of gastric glands present in the digestive system and depending on the region in the stomach, these gastric glands are divided into 3 major parts:-    

1. Cardiac Glands – These glands are located close to the cardiac orifice. They usually contain cardiac glands. Also, they are comparatively very few in number and are positioned in the mucosa shallowly. These are generally of two kinds, which are the simple tubular (like those of pyloric ends) and short ducted, and the compound racemose resembling the duodenal glands. Their main function in the digestive system is to secrete mucus. 

2. Fundic Glands – These glands are located in the fundus or body of the stomach. They are straight, parallel, tube-like structures. It has been observed that two or more of such tubes open into a common duct. Also, these tubes are at most one-sixth the length of the entire gland. These glands are much shorter than the pyloric glands. These glands are lined by columnar epithelium. Their main function in the digestive system is to produce digestive enzymes.

3. Pyloric Glands – These glands are the endocrine glands located in the antrum, known as the pyloric portion of the stomach. They consist of two or three short, wavy closed tubes which open into a common duct. These tubes are generally half the length of the entire duct. The duct is usually lined by columnar cells and the tubes by short, granular cubical cells. The main function of these glands is to secrete gastrin (produced by G cells) and mucus. 

The mucus which is produced by the Cardiac glands and the Pyloric glands coats the stomach, dilutes the acids and enzymes, and hence protects the oesophagus and the duodenum from self-digestion.