describe the process of nutrition in humans
Answers
Answer:
Five Stages of Human Nutrition. In order to accomplish its functions the digestive system begins with the mouth where food enters. This process is called ingestion. ... After the food is absorbed the nutrients are brought to the body cells.
Answer:
Hi ..
Explanation:
- Nutrition in Human Beings (Complex Multicellular Animal):
- The various organs of the human digestive system in sequence are: Mouth, Oesophagus (Food pipe), Stomach, Small intestine and Large intestine.
- The glands which are associated with the human digestive system are: Salivary glands, Liver and Pancreas.
The various steps of nutrition in human beings are as follows:
1. Ingestion:
In human beings, food is ingested through the mouth. The food is put into the mouth with the help of hands.
2. Digestion:
The digestion of food begins in the mouth itself.
The teeth cut the food into small pieces, chew and grind it. (Physical digestion)
The salivary glands in our mouth produce saliva (watery liquid) which contains an enzyme salivary amylase which digests the starch (carbohydrate) present in the food into sugar. (Chemical digestion)
Our tongue helps in mixing this saliva with food.
The digestion of food remains incomplete in mouth.
3. Oesophagus:
The slightly digested food in the mouth is swallowed by the tongue and goes down the food pipe called oesophagus.
When the slightly digested food enters the food pipe, the walls of food pipe start contraction and expansion movements called as peristaltic movement.
This peristaltic movement of food pipe pushes the slightly digested into the stomach.
4. Stomach:
The stomach is a J-shaped organ present on the left side of the abdomen.
The stomach walls contain s three tubular glands in it walls which secrete gastric juice.
The gastric juice contains three substances: Hydrochloric acid, the enzyme pepsin and mucus.
The hydrochloric creates an acidic medium which facilitates the action of the enzyme pepsin i.e. digestion of protein.
The mucus helps to protect the stomach wall from its own secretions of hydrochloric acid.
The partially digested food then goes from the stomach into the small intestine.
5. Small intestine:
From the stomach, the partially digested food enters the small intestine.
The small intestine is the largest part (about 6.5m) of the alimentary canal.
The small intestine is very narrow and arranged in the form of a coil in our belly.
The small intestine in human beings is the site of complete digestion.