The Digestive System
Major Function
The major function of the digestive system is to process food, extract nutrients from it, and eliminate excess waste. There are 4 stages to digestion: Ingestion, digestion, absorption, and defecation. Diseases
Dysphagia: Leads to difficulty swallowing, and can be caused by tumors, constrictions, or impaired peristalsis. Crohn's Disease: An inflammatory bowel disease that can affect the large and small intestines, and cause diarrhea and lower abdominal pain. Ulcerative Colitis: An inflammatory bowel disease that results in ulceration of the large intestine |
Fun Facts
-The small intestine is 19-23 ft long, and 1 inch wide -The large intestine is 5 ft long and 2.5 inches wide - The esophagus can pass food to the stomach, even if you are upside down -An average adult male will consume 50 tons of food in their lifetime -The average adult generates one point seven liters of saliva every day |
Major Organs
-Tongue: A muscle in the mouth that contains taste buds for tasting food
-Teeth: The teeth are a are located in the mouth in 2 distinct rows, and they help grind and tear food for ingestion
-Pharynx: Located between the mouth and the esophagus, helps push food from the mouth to the esophagus
-Esophagus: A muscular tube that transports food from the mouth to the stomach
-Stomach: A food storage organ that breaks up food particles and begins the chemical digestion process
-Liver: The body’s largest gland, it secretes bile,which contributes to digestion
-Pancreas: A gland that secretes insulin and glucagon, as well as pancreatic juice
-Gallbladder: Stores and concentrates bile
-Small Intestine: The largest part f the digestive tract, it handles almost all of the chemical digestion and nutrient absorption
-Duodenum: Receives the stomach nutrients, pancreatic juice, and bile. Neutralizes stomach acid, breaks up fats, inactivates pepsin.
-Jejunum: Where digestion and nutrient absorption occurs
-Ileum: The last segment of the small intestine until the large intestine
-Large Intestine: Receives indigestible food, converts it to feces, and eliminates it through defecation
-Ascending colon: The first segment of the colon
-Descending colon: The part of the colon that passes down the left side of the abdominal cavity -Transverse colon: Passes horizontally across the upper abdominal cavity
-Sigmoid colon: The s shaped part of the colon in the pelvic cavity.
-Appendix: A source of immune cells and lymphocytes, attached to the cecum.
-Tongue: A muscle in the mouth that contains taste buds for tasting food
-Teeth: The teeth are a are located in the mouth in 2 distinct rows, and they help grind and tear food for ingestion
-Pharynx: Located between the mouth and the esophagus, helps push food from the mouth to the esophagus
-Esophagus: A muscular tube that transports food from the mouth to the stomach
-Stomach: A food storage organ that breaks up food particles and begins the chemical digestion process
-Liver: The body’s largest gland, it secretes bile,which contributes to digestion
-Pancreas: A gland that secretes insulin and glucagon, as well as pancreatic juice
-Gallbladder: Stores and concentrates bile
-Small Intestine: The largest part f the digestive tract, it handles almost all of the chemical digestion and nutrient absorption
-Duodenum: Receives the stomach nutrients, pancreatic juice, and bile. Neutralizes stomach acid, breaks up fats, inactivates pepsin.
-Jejunum: Where digestion and nutrient absorption occurs
-Ileum: The last segment of the small intestine until the large intestine
-Large Intestine: Receives indigestible food, converts it to feces, and eliminates it through defecation
-Ascending colon: The first segment of the colon
-Descending colon: The part of the colon that passes down the left side of the abdominal cavity -Transverse colon: Passes horizontally across the upper abdominal cavity
-Sigmoid colon: The s shaped part of the colon in the pelvic cavity.
-Appendix: A source of immune cells and lymphocytes, attached to the cecum.