The digestive system consists of the digestive tract and other organs that help in the breakdown and absorption of food by the body. It is a long, twisted tube that begins in the mouth and travels through the oesophagus, stomach, small intestine, large intestine, and anus.
Food is broken down into nutrients, including carbohydrates, fats, and proteins, by the digestive system. They may then be taken into the bloodstream and used for energy, development, and repair by the body. Unused materials are disposed of in the form of faeces.
ORGANS OF THE DIGESTIVE SYSTEM
Each digestive system organ plays a vital part in digestion.
Mouth
The teeth break food into extremely small pieces when someone eats. Saliva is produced by glands in the cheeks and under the tongue, which coats the food and makes it simpler to chew and swallow. Saliva also includes enzymes that begin the process of breaking down carbs in food.
Oesophagus
The muscular tube that transports food from the mouth to the stomach after it has been swallowed is known as the oesophagus. A ring of muscle at the oesophagus’s end relaxes to let food into the stomach and tightens to prevent stomach contents from escaping back up the oesophagus.
Stomach
Gastric juice is produced by the stomach wall and is used to breakdown proteins. The stomach churns and mixes food with gastric juice to produce chyme, a thick, soupy liquid.
Small intestine
The gallbladder’s bile and enzymes in the pancreas’ digestive juices flow into the upper section of the small intestine, where they help in the breakdown of protein into amino acids and fat into fatty acids. The small intestinal wall absorbs these tiny particles, as well as carbohydrates, vitamins, and minerals, into the bloodstream.
It’s termed small because it’s just around 3.5cm in diameter, but it’s roughly 5m long, which means there’s plenty of area for absorption. The small intestine is where most of the chemical digestion of proteins, fats, and carbohydrates takes place.
Large intestine and anus
The walls of the large intestine absorb water, mineral salts, and vitamins. Undigested fibre is combined with mucus and bacteria, which assist to break down the fibre, to nourish the cells of the large intestine wall and keep it healthy. Before being discharged out of the body through the anus, faeces are produced in the last part of the large intestine (the rectum).
The Pancreas
Pancreas helps the small intestine by secreting pancreatic juice, which is liquid rich in enzymes and sodium bicarbonate that can stop pepsin digestion. It also produces insulin, which helps in blood sugar regulation.
The Liver
The liver serves a variety of purposes. It generates bile, which is used by the small intestine to help in the digestion of fats in food. It also helps manage blood sugar levels, stores glycogen for immediate energy, manufactures fibrinogen, which clots blood, creates vitamin A, and recycles worn-out red blood cells, etc. Because the liver is involved in so many important aspects, such as digestion, diseases of the liver, such as hepatitis, can have serious consequences that impact other parts of the body.
The Gallbladder
The gallbladder is a storage container for bile, a yellow-green fluid made up of salts, cholesterol, and lecithin that lies tucked under the liver. Fats are broken down in the small intestine using bile. Most individuals don’t give their gallbladder much thought until they have gallstones or gallbladder illness, such as cholecystitis. You may get jaundice if you have a gallbladder problem. This occurs when bile is unable to exit the gallbladder. Bile instead enters the bloodstream, causing your skin, eyes, and nails to become yellow.
FUNCTIONS OF THE DIGESTIVE SYSTEM
The function of the digestive system is to digest and absorb food.. Food is broken down into little molecules, which are subsequently taken into the body during digestion. There are two key sections of the digestive system:
- The alimentary canal is a continuous tube with two openings: the mouth and the anus. The mouth, pharynx, oesophagus, stomach, small intestine, and large intestine are all included in the system. Food that travels through the digestive tract’s interior cavity, or lumen, does not technically enter the body until it is absorbed through the walls and enters blood or lymphatic arteries.
- The teeth and tongue, salivary glands, liver, gallbladder, and pancreas are known as accessory organs.
The following seven processes are involved in the digestive system’s handling of food:
- Ingestion is the process of eating.
- Food movement along the digestive tract is referred to as propulsion. Peristalsis, a sequence of alternating contractions and relaxations of smooth muscle that lines the walls of the digestive organs and pushes food forward, is the primary source of propulsion.
- Digestive enzymes and other chemicals secreted by the body liquefy, change the pH of, and chemically break down food.
- The act of physically breaking down food into smaller bits is known as mechanical digestion. The chewing of food initiates this process, which is followed by the muscular churning of the stomach. The small intestine undergoes additional churning due to muscle constriction of the intestinal wall. This mechanism, known as segmentation, is similar to peristalsis, except that the food is forced backward and forward rather than forward solely due to the rhythmic timing of the muscle constrictions.
- Chemical digestion is the process of breaking down food into smaller molecules chemically. Enzymes in the stomach and small intestines carry out the procedure.
- Absorption is the transportation of chemicals from the digestive system to nearby blood and lymphatic arteries (through passive diffusion or active transport). The entrance of digested food (now called nutrients) into the body is referred to as absorption.
- Defecation is the process of removing undigested matter from the body through the anus.
CONCLUSION
Digestion is the process through which the human body breaks down food into a form that can be absorbed and used as fuel. The mouth, oesophagus, stomach, pancreas, liver, gallbladder, small intestine, large intestine, and anus are the organs of the digestive system. Understanding how these organs work together to digest food is crucial to understand digestion. Human body need nutrients from the food we consume and the liquids we drink to keep it healthy and perform correctly. Carbohydrates, proteins, fats, vitamins, minerals, and water are all nutrients. Your digestive system breaks down and absorbs nutrients from the food and liquids you ingest so that they may be used for vital functions such as energy, cell growth, and cell repair.