Digestion and Teeth
Concept: Digestion and Digestive Disorders
What is digestion?
Digestion is defined as the conversion of complex food into simple nutrients.
After digestion, carbohydrates get converted into glucose, fats into fatty acids and glycerol and proteins into amino acids.
The glucose, fatty acids, glycerol, and amino acids get absorbed in the bloodstream and are then transferred to all the body cells.
Steps of Nutrition
Nutrition is the process by which our body nourishes itself by transforming food into utilisable energy.
- Salivary gland:
- The process of intake of food through the buccal cavity is called ingestion.
- Digestion starts in the buccal cavity.
- The food we eat majorly comprises carbohydrates, fats and proteins.
- The first component of the food that is digested is carbohydrates.
- The food in the buccal cavity is mixed with saliva with the help of the tongue.
- Amylase present in saliva starts the breakdown of carbohydrates into sugars.
- This is why we get a sweet taste after chewing carbohydrate-rich foods for some time.
- Once the food is chewed properly, it is swallowed and passed to the stomach.
- The wall of the stomach secretes enzymes and hydrochloric acid, which aids digestion.
- Hydrochloric acid kills the unwanted bacteria and microbes that enter the alimentary canal along with food.
- The food is churned, and the digestion of protein and fats is triggered in the stomach.
- Then the food is passed to the small intestine. The secretions of the liver and pancreas are secreted in
the first part of the
small intestine, i.e. duodenum. Once the enzymes in these secretions complete their work, the complete digestion of food takes place in the small intestine.
- Carbohydrates convert into sugars, proteins into amino acids, and fats into fatty acids and glycerol on complete digestion.
- The wall of the small intestine has small finger-like projections.
- These projections are called villi, and they are supplied with blood vessels.
- The food when transfers through the walls of the small intestine, facilitates the entry of digested nutrients into the blood.
- Once the nutrients enter the bloodstream, it is transferred to all the cells of the body.
- In the cells, the nutrients are oxidised in the presence of oxygen to release heat and energy.
- The body uses this energy for continuing the vital life processes.
- The undigested food is sent to the large intestine.
- The walls of the large intestine absorb water present in the undigested food.
- The solid waste is then transferred to the rectum where it is stored for a while and then egested out through the anus.
- Constipation: The condition in which the passage of stool becomes less frequent because it is difficult to egest the faecal matter as it becomes hard.
- Diarrhoea: The condition in which watery stool is passed frequently. It may be
caused due to bacteria or fungi present in food when it is not cleaned or cooked properly.
Diarrhoea may sometimes lead to dehydration due to excess loss of water.
- Heartburn: It is the uncomfortable burning sensation that a person suffers in the chest, neck or throat region due to overproduction of hydrochloric acid in the stomach.
- Haemorrhoids: This condition arises due to swollen and enlarged blood vessels in the anal region. It leads to a painful sensation while passing the stool.
- Ulcers: These are sores that develop in the lining of the stomach, small intestine or large intestine due to bacterial infection. Ulcer exposes the blood vessels and may lead to a severe condition if not treated timely.
- Gall stones: Small insoluble solid stone-like structures that accumulate in the gall bladder.
- Lactose intolerance:In this case, an individual cannot digest lactose-rich food items like milk or dairy products.
- Celiac disease: An disease in which the small intestine gets damaged by the consumption of gluten, a type of protein found in wheat and barley.
Practices to keep the digestive system healthy:
- Drink plenty of water: Water helps in the smooth movement of food through the alimentary canal. Water also prevents the problem of constipation.
- Include roughage in diet:Roughage is rich in fibre which does not have any nutritional value but aids the digestion of food by regularising the bowel movements.
- Balanced diet: A balanced diet with the right proportions of carbohydrates, proteins, fats, vitamins, and minerals keeps the digestive system healthy.
- Include probiotic-rich foods Live bacteria and yeast found in probiotic-rich foods help maintain the health of the alimentary canal and assist in digestion. Examples:Curd, yoghurt, kefir.
- Chew your food properly:Food, when chewed properly, adds enough saliva to the food, which aids in digestion.Chewing enhances digestion and helps in better absorption of nutrients in the bloodstream.
- Regular exercise:Exercise allows proper movement of food through the alimentary canal.
Roughage: Plant foods rich in cellulose that cannot be digested by the body but are helpful for the passage of food.
Probiotics: Live microbes, usually bacteria and yeast found in food that are supposed to be beneficial for the body.
Kefir:A fermented milk drink made using bacteria and yeast. It has a lot of health benefits and is sour to taste.
Did You Know?
- The hydrochloric acid produced in the stomach is a mineral acid that can burn the skin, but the mucus membrane present on the stomach wall prevents these burns.
- Endoscopy is a modern surgical technique that helps doctors peep inside the body's digestive tract by using an endoscope.
- If a person’s bowel movements do not happen every day, the situation cannot be considered abnormal. The bowel movements for a healthy person can vary from 3 days to 3 weeks.