The Human Digestive System

Ever wondered what happens to that sandwich after you swallow it? Your digestive system is essentially a long tube with specialised organs working together to extract nutrients from food.

The journey starts in your mouth, where your teeth provide mechanical digestion by physically breaking food apart. Meanwhile, saliva containing the enzyme amylase begins chemical digestion by breaking down starches into sugars.

When you swallow, the epiglottis (a flap of muscle) cleverly closes over your windpipe, directing food safely into the oesophagus. This muscular tube uses peristalsis - rhythmic squeezing motions - to push food towards your stomach, meaning food can only travel in one direction.

Your stomach is where the real action begins. Stomach muscles continue mechanical digestion whilst stomach acid and the enzyme pepsin break proteins into amino acids. Don't worry about the acid dissolving your stomach - mucus protects the stomach lining!

Quick Tip: Remember that digestion involves both mechanical (physical) and chemical (enzyme) processes working together.

The small intestine is perfectly designed for absorption. Its large surface area (created by folds and tiny hairs called villi), excellent blood supply, and short diffusion distance make it incredibly efficient at absorbing nutrients into your bloodstream through diffusion and active transport.

Your liver is basically a multitasking champion with over 200 jobs, including producing bile (stored in the gall bladder) to break down fats, regulating sugar storage, and filtering old red blood cells. The pancreas creates essential enzymes, including lipase for breaking down lipids.

Finally, the large intestine absorbs water from undigested food, forming faeces that are stored in the rectum before being eliminated through the anus.