Question

What are the different stages of digestion?

Answer 1

Digestion:

1. It is defined as a process in which the large insoluble food particles are broken down into smaller soluble particles that can be absorbed by the body.
2. Ingestion, propulsion, mechanical or physical digestion, chemical digestion, absorption, and defecation are the six operations of digestion.

Ingestion:

1. This is the first process of digestion.
2. The organs involved in ingestion are the mouth, tongue, teeth, and other complementary substances such as saliva.
3. In this process, the food is taken and chewed well by the mouth and tongue.
4. The food is mixed well with the saliva. During the chewing process, substances are broken down and absorbed, especially carbon dioxide.
5. Then the food moves to the next part of the stomach.
6. Some of the other functions of the mouth are that it moistens the food and dissolves it.
7. Saliva that is secreted helps in cleaning the teeth and oral cavity.

Propulsion:

1. This process of digestion involves propelling the food particles into the next organs.
2. The pharynx and esophagus help in the propulsion.
3. It helps in transferring food to the next stage of the organ which is the esophagus.
4. This part of the digestive system helps in lubricating the food and the pathway.
5. It also has the same function as that of the pharynx, which is it helps in lubrication and propelling food to the stomach.

Physical and chemical digestion:

1. The major part of the physical digestion occurs in the stomach, and chemical digestion occurs in the small intestine.
2. The stomach is the main organ that places an important role in churning food.
3. The stomach secrets juices such as gastric juices that mix with the broken food and form chyme.
4. The breakdown of the proteins takes place in the stomach.
5. The small intestine is a long narrow tube-like stricture that enables slow movement of food.
6. It is the place where most of the food is absorbed into the body.

Absorption:

1. A little number of carbohydrates are also absorbed into the mouth by the saliva.
2. It is observed that some fat that is ingested is being absorbed by the stomach.
3. The absorption of carbohydrates, proteins, lipids, nucleic acids, minerals, and vitamins is all absorbed in the small intestine of the digestive system

Defecation:

1. It is the last part of the digestive system.
2. It absorbs most of the water, electrolytes, and vitamins that are produced by the bacteria.
3. The undigested food thus passes through the large intestine and forms faeces, that will be released through the anus.
4. The food that is consumed is constantly being digested and stored prior to defecation.