Your digestive system
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The Function of the Digestive System
The human digestive system is responsible for taking in food (ingestion) and breaks it down into the nutrient molecules that sustain life (digestion). The nutrient molecules are then absorbed into the blood so they can be delivered to cells all over the body. Once a majority of the nutrients have been absorbed by the body it is removed from the body.
The Structure of the Digestive System
The human digestive system is responsible for taking in food (ingestion) and breaks it down into the nutrient molecules that sustain life (digestion). The nutrient molecules are then absorbed into the blood so they can be delivered to cells all over the body. Once a majority of the nutrients have been absorbed by the body it is removed from the body.
The Structure of the Digestive System
- Mouth
- tounge
- salivary glands
- parotid gland
- sublingual gland
- submandibular gland
- pharynx- the pharynx is subdivided into three sections the oropharynx, laryngopharynx and nasopharynx. The nasopharynx is also a part of the respiratory passageway. The oropharynx is located behind the oral cavity. the laryngopharynx continues down into the esophagus.
- esophagus
- smooth muscles- wave like muscle contractions in the esophagus that helps to move food through the esophagus
- The esophagus is also lined with cilia to help move food down to the stomach.
- stomach
- cardiac sphincter between the stomach and esophagus
- contains hydrochloric acid to help breakdown food. The HCl allows the proper environment for pepsin to breakdown proteins in the food that is being digested. Additionally HCl provides the body with a defense mechanism against bacteria that may be present in the food we ingest.
- pyloric sphincter- between the stomach and small intestine. The pyloric sphincter prevents the back flow of food between the stomach and small intestine. It also prevents HCl from entering the small intestine and causing damage.
- liver
- the liver has many regulatory and metabolic roles.
- adds bile which breaks down lipids. The bile produced by the liver is secreted through the common hepatic duct and enters the duodenum through bile ducts. Bile contains bile salts which are what break down food during the digestion process.
- gallbladder
- The gallbladder stores excess bile that is secreted from the liver to the gallbladder via the cystic duct.
- The gallbladder secretes a more concentrated bile, which is produced in the gallbladder by removing water, when fatty foods enter the duodenum
- pancreas
- produces trypsin, chymotrypsin, and carboxypeptidase
- help break down polypeptides (proteins)
- also helps break down fat with lipase
- spleen
- small intestine- villi in the small intestine absorb the nutrients from the chyme
- where chemical digestion occurs
- duodenum
- jejunum
- ileum
- large intestine
- there are no villi present in large intestine since many of the nutrients have been previously absorbed.
- transverse colon
- descending colon
- ascending colon
- cecum
- sigmoid colon
- rectum
- appendix
- anal canal
- anus