Question

Describe the process of ingestion of food.

Answer 1

Hint: Various different organs and enzymes are responsible for breaking down consumed food. The human digestive system begins from the mouth and ends at the anus. The organs involved in the digestion process are mouth, esophagus, pharynx, stomach, small intestine, large intestine and anus.

Complete answer: The process of ingestion of food refers to the consumption of the food. The human digestive system also called an alimentary canal or gastrointestinal canal comprises the following organs: mouth, oesophagus, pharynx, stomach, small intestine, large intestine, anus and also accessory organs.
a) Mouth: It is the part of the digestive canal where the bolus of food is ingested, crushed and chewed with the help of teeth and tongue. The salivary glands situated in the mouth secrete saliva which makes the food moist and soluble. Breakdown of carbohydrates takes place in the mouth.
b) Pharynx: it is the part of both the respiratory system and the digestive system. Its role is to conduct food to the oesophagus.
c) Esophagus: It is a muscular tube which runs from the pharynx to the stomach and is also called a food pipe. The food is conducted to the stomach via the esophagus by a process called peristalsis. It is the rhythmic movement of relaxation and contraction which pushes the food downward towards the stomach. This rhythmic movement of contraction and relaxation is called peristalsis.
d) Stomach: it is a J-shaped organ with oesophagus located above it and duodenum located at the lower end. Here the churning of food takes place. It acts similar to a mixer in which the food is completely churned. Digestion of protein takes place in the stomach.
e) Small intestine: The food received from the stomach is partially digested and is in the semi-liquid form known as chyme. Duodenum, jejunum and ileum together form the small intestine. Absorption of nutrients, sugars, amino acids and fatty acids takes place in the small intestine. The remaining waste deprived of nutrients is converted into semi-solids known as faeces.
Large intestine: here the absorption of remaining minerals and water takes place and the faeces is pushed into the rectum by the peristalsis movement and is finally expelled through the anus.

Note: Other than digestive organs, accessory organs also play a vital role in the digestion of food. Accessory organs involved in the digestive system are tongue, salivary gland, pancreas, liver and gallbladder. These organs produce digestive juices and enzymes necessary for the process of digestion of food. Saliva, amylase and lipase are secreted by salivary gland. Bile is produced by liver and pancreas secrete pancreatic juices.