Tag: process of digestion

The fundus is the upper, rounded part of the stomach, located above the level of the cardiac orifice. The cardiac part is where the esophagus enters, and the pyloric part is the lower section leading to the duodenum.

Lacteals are lymphatic capillaries located in the villi of the small intestine of vertebrates, specialized for the absorption of dietary fats and fat-soluble vitamins.

The gastric juice is made up of hydrochloric acid, pepsinogen and other digestive enzymes, gastrin, mucus, and bicarbonates. It has a pH ranging from 1 to 2. Its low pH is essential in activating digestive enzyme such as pepsinogen and convert it into the active pepsin, a Proteolytic activity of pepsin and in destroying various pathogens. 

The stomach wall consists gastric gland which secretes gastric juice for digestion of food. The gastric juice is made up of hydrochloric acid, pepsinogen and other digestive enzymes, gastrin, mucus, and bicarbonates. It has a pH ranging from 1 to 2. Its low pH is essential in activating many digestive enzymes and in destroying various pathogens. Thus, the correct answer is option C.

According to the body's needs, the stomach decides what to do with the food. If the small intestine is full and busy absorbing molecules from a previous meal, for instance, the stomach temporarily stores the food. On the other hand, if the body is in need of nutrients and the small intestine is ready for absorption, the stomach begins to break down the macromolecules found in the food and creates a semi-liquid mixture called chyme. This decision-making step of the stomach helps control the pace of the digestive system. The stomach of vertebrates is able to break down macromolecules due to its highly acidic environment, which causes molecular bond stress and forces them to break. So, the original function of the vertebrate stomach was storage but, due to acidic medium it also breaks down the food. Thus, option A is correct.

During digestion process fist food is ingested by mouth where chewing churning and mixing of food take place and make semi solid paste of food called as a bolus. Bolus then enters into the oesophagus where food moves through peristaltic movement and enters into the stomach. Thus, the correct answer is option C.

The stomach wall secretes gastric juices and a mixture of HCl, pepsinogen and mucous. HCl increases the pH of the stomach due to which pepsinogen gets activated and gets converted into the active form pepsin which digests the protein molecule. Thus, the correct answer is option D. 

The stomach is a J-shaped, hollow organ located just inferior to the diaphragm in the left part of the abdominal cavity. It is located between the oesophagus and connects with the duodenum. It has two parts fundus and pyloric.