Digestion begins the moment you put food into your mouth. Your teeth chew the food into smaller pieces, making it easier to swallow. Saliva, which is produced by glands in your mouth, mixes with the food. Saliva contains an enzyme called amylase that starts to break down carbohydrates. Your tongue helps push the chewed food to the back of your throat, and then it enters a tube called the oesophagus. This whole process turns the food into a soft lump called a bolus. Chewing thoroughly helps your body get the most nutrients from food.

The oesophagus is a muscular tube that connects your mouth to your stomach. It uses waves of muscle contractions, called peristalsis, to push the bolus down. This happens even if you are standing on your head. At the bottom of the oesophagus is a ring of muscle called the lower oesophageal sphincter. It opens to let food into the stomach and then closes to prevent stomach acid from flowing back up. The stomach is a strong, stretchy bag that churns the food and mixes it with gastric juices. These juices contain hydrochloric acid and enzymes that break down proteins.

The stomach turns the bolus into a liquid mixture called chyme. After about two to four hours in the stomach, the chyme passes into the small intestine. The small intestine is about six metres long but is coiled up inside your abdomen. Its inner surface has millions of tiny finger-like projections called villi. These villi increase the surface area for absorbing nutrients. The first part of the small intestine, called the duodenum, receives bile from the liver and enzymes from the pancreas. Bile breaks down fats, and pancreatic enzymes continue digesting proteins, carbohydrates, and fats.

It opens to let food into the stomach and then closes to prevent stomach acid from flowing back up.

The nutrients from the chyme are absorbed through the villi into the bloodstream. Whatever is not absorbed in the small intestine moves into the large intestine. The large intestine is about 1. 5 metres long and wider than the small intestine. Its main job is to absorb water and salts from the leftover material. As water is absorbed, the remaining waste becomes more solid, forming faeces. The large intestine also contains billions of bacteria that help break down any remaining food and produce vitamins like vitamin K. These bacteria are important for your health.

The waste slowly moves through the large intestine towards the rectum, where it is stored until you go to the toilet. The nutrients absorbed by the small intestine are carried to the liver through the hepatic portal vein. The liver processes these nutrients, storing some and releasing others into the bloodstream for the body to use. Glucose, a type of sugar from carbohydrates, is used for energy. Amino acids from proteins are used to build and repair cells. Fatty acids and glycerol from fats are used for energy and cell membranes.

Vitamins and minerals help with various functions, like keeping bones strong and helping nerves work. Without proper digestion, your body cannot get these essential building blocks. In summary, digestion is a complex process that breaks down food into nutrients your body can use. Each part of the digestive system has a specific role, from the mouth to the large intestine. Chewing food well and eating a balanced diet help your digestive system work efficiently. Problems like indigestion or heartburn can occur if parts of the system do not function properly. Understanding how your body digests food can help you make better choices about what you eat and how you eat it. A healthy digestive system is key to feeling good and having energy every day.