Final answer:
The digestive system consists of the mouth, esophagus, stomach, small intestine, and large intestine, as well as the rectum and anus. It also includes accessory organs like the salivary glands, liver, gallbladder, and pancreas. Together, these structures form a continuous alimentary canal from mouth to anus, which is responsible for digestion and waste elimination.
Step-by-step explanation:
The human digestive system, often referred to as the gastrointestinal (GI) tract, is a complex series of organs that facilitate the breakdown, digestion, absorption of nutrients, and expulsion of waste from the body. The main components of the digestive system include the mouth, where the digestion process begins, esophagus, stomach, small intestine, and large intestine. Additionally, the system includes the rectum and anus, which are involved in the expulsion of digestive waste. Accessory organs, such as the liver, gallbladder, and pancreas, produce essential digestive enzymes and substances. The alimentary canal, which includes the aforementioned organs, forms a contiguous passage way from the mouth to the anus, extending approximately 30 feet in adults.
The mouth contains the teeth, gums, and tongue, all of which assist in breaking down food. The esophagus transports chewed food to the stomach, where it is further broken down by gastric juices. The small intestine is the site of most nutrient absorption and is divided into three parts: the duodenum, jejunum, and ileum. The large intestine absorbs water and electrolytes, forming stool which is then passed through the rectum and expelled from the body via the anus. Digestive processes are also aided by accessory organs, including the salivary glands, liver, which produces bile, the gallbladder, which stores bile, and the pancreas, which secretes digestive enzymes.