Yläruuansulatuskanava

Yläruuansulatuskanava refers to the upper part of the digestive tract. It encompasses the organs responsible for the initial stages of food intake, breakdown, and transport down towards the stomach. This region begins with the mouth, where food is ingested and mechanically broken down by chewing, and saliva initiates chemical digestion. From the mouth, food passes through the pharynx, a passageway shared with the respiratory system, and then down the esophagus. The esophagus is a muscular tube that uses peristalsis, wave-like muscle contractions, to move food to the stomach. The stomach is a J-shaped organ that further digests food through the action of acids and enzymes. It also plays a role in storing food temporarily. The pyloric sphincter at the lower end of the stomach controls the passage of partially digested food, known as chyme, into the small intestine, which is considered part of the lower digestive tract. Therefore, the yläruuansulatuskanava comprises the mouth, pharynx, esophagus, and stomach. These organs are crucial for preparing food for further digestion and absorption in the lower digestive system.