Essay about Human Digestive System
Single-celled organisms can directly take in nutrients from their outside environment. Multi-cellular animals, with most of their cells removed from contact directly with the outside environment, have developed specialized structures for obtaining and breaking down their food. The human digestive system is a complex series of organs and glands that processes food. It is a coiled, muscular tube (6-9 meters long when fully extended) extending from the mouth to the anus. Inside this tube is a lining called the mucosa. In the mouth, stomach, and small intestine, the mucosa contains tiny glands that produce juices to help digest food. This tube also includes the pharynx, esophagus, large intestine, and anus. …show more content…
What causes the stomach to growl?
Stomach growling occurs when the stomach receives signals from your brain to begin digestion but the stomach is empty. The brain might sense you're running low on energy (glucose) or even seeing or smelling something you want to eat can get things going. The motion of the stomach muscles begins, but the organ is hollow. The movement of the muscles mixing the acids of the stomach in the hollow space of the stomach produces vibrations we hear as growling, or rumbling, or gurgling.
Production of Digestive Juices
In the salivary glands. Saliva produced by these glands contains an enzyme that begins to digest the starch from food into smaller molecules.
The next set of digestive glands is in the stomach