The Journey of Your Food
Where does that slice of pizza go after you take a bite? It begins a long journey through your digestive system, a group of organs that work together to break down food into tiny molecules that your body can absorb and use for energy, growth, and repair. This process is called digestion.
There are two types of digestion:
Mechanical Digestion: The physical breakdown of food into smaller pieces. This increases the surface area for chemical digestion to work on.
Chemical Digestion: The chemical breakdown of large food molecules into smaller ones using enzymes, which are special proteins that speed up chemical reactions.
The Path of Digestion
1.Mouth: The journey starts here. Your teeth perform mechanical digestion by chewing and grinding the food. Your salivary glands release saliva, which contains an enzyme called amylase that begins the chemical digestion of carbohydrates (starches).
2.Esophagus: After you swallow, the food travels down the esophagus, a muscular tube that connects your mouth to your stomach. Muscles in the esophagus contract in a wave-like motion called peristalsis to push the food along.
3.Stomach: The stomach is a J-shaped muscular organ. It continues mechanical digestion by churning and mixing the food. It also performs chemical digestion. The stomach lining releases strong hydrochloric acid and an enzyme called pepsin to begin breaking down proteins. The acid also kills harmful bacteria. The soupy mixture of partially digested food is now called chyme.
4.Small Intestine: This is where the most important work happens! The small intestine is a long, coiled tube where most of the chemical digestion and absorption of nutrients occurs.
The liver produces bile, which is stored in the gallbladder and released into the small intestine to help break down fats.
The pancreas produces several powerful enzymes that break down carbohydrates, proteins, and fats.
The walls of the small intestine are lined with tiny, finger-like projections called villi, which vastly increase the surface area for absorbing the small nutrient molecules into the bloodstream.
5.Large Intestine (Colon): Any leftover material that couldn't be digested (like fiber) moves into the large intestine. The main job of the large intestine is to absorb water from the remaining waste material and form solid feces.
6.Rectum and Anus: The solid waste (feces) is stored in the rectum until it is eliminated from the body through the anus.