Question

The inner lining of the stomach secretes
a. Mucous
b. Hydrochloric acid
c. Digestive enzymes
d. All of the above

Answer 1

Hint: The different organs of the body are responsible to perform specific functions that are required for biological activities. The stomach is one of the most important organs of the digestive system and it receives the food from the esophagus.

Complete answer:
The stomach is a hollow, muscular organ that is located between the esophagus and the small intestine. It is a vital organ of digestion as it is involved in the second phase of digestion of the chewed food.

The stomach performs various enzymatic reactions by the process of chemical reaction by the means of enzymes and hydrochloric acid. The wall of the stomach consists of several layers such as the mucosa, submucosa, muscularis externa, subserosa and serosa.

The innermost lining of the stomach is known as the gastric mucosa. It consists of an outermost layer of column-shaped cells, a lamina propria and a thin layer of smooth muscles which is known as the muscularis mucosa. The mucosa lining of several pits which receives the gastric juices. The gastric juices are secreted by the gastric glands. Gastric juices contain digestive enzymes pepsin. The fundic glands present in the inner lining and they are lined by column shaped cells. These cells secrete a protective layer of mucus and bicarbonate. The innermost lining of the stomach secretes mucus, hydrochloric acid as well as certain types of digestive enzymes to digest or breakdown the food present in the stomach.

In addition to this, some other types of cell are also found which are known as the parietal cells. It secretes hydrochloric acid which plays an important role in digestion of the food materials. The chief cells present are responsible for secreting enzyme pepsinogen. The enzyme pepsinogen acts as the precursor of pepsin.

Hence, the correct answer is option (D).

Additional information:
The gastric juices present in the stomach contains pepsinogen and hydrochloric acid. Hydrochloric acid activates the inactive form of the enzymes into active pepsin. Pepsin further breaks down the proteins into polypeptides.

Note: The stomach secretes digestive enzymes as well as gastric juices that helps in the process of further digestion of food. The inner lining of the stomach contains several types of glands and cells that are responsible for the secretion of mucous, digestive enzymes and hydrochloric acid.