Presentation on theme: "The Digestive System Hey- chew on this! We’ve made it to the.."— Presentation transcript:
The Digestive System Hey- chew on this! We’ve made it to the..
Gastrointestinal System Function-physical and chemical breakdown of food Includes alimentary canal and accessory organs Accessory organs: Salivary glands, tongue, teeth, liver, gallbladder, and pancreas
Alimentary canal Mouth- physical and chemical breakdown. Mastication-the act of chewing Saliva contains enzyme amylase to break down carbohydrates
Pharynx- contains opening to trachea as well. Epiglottis covers opening of trachea. Esophagus-muscular tube dorsal to trachea Relies on a rhythmic wave-like motion called peristalsis
Sphincter-a circular muscle that constricts a passage or closes a natural orifice (opening) Cardiac sphincter Pyloric sphincter Food sits in stomach for 1-4 hours. Gastric juices contain hydrochloric acid- activates pepsin, kills bacteria.
Small intestine: not so small! 20ft x 1’’ Duodenum- 1 st 10 inches. Bile and pancreatic juice enter here Jejunum- next 8 ft. Ileum- final 12 ft. When food leaves small intestine, digestion is complete
Small intestine has lots of enzymes: peptidases maltase, sucrase, lactase, amylase. Lipase Bile Digested food is absorbed into the bloodstream.
Large intestine- 5 ft x 2’’. Separated from small intestine by ileocecal valve Final absorption of water, storage of indigestible material, absorption of vitamins B and K by bacteria. Colon connects to rectum- anal canal opens to the anus (final opening). Fecal material is expelled.
But Wait! What about the accessory organs: Liver, gall bladder and pancreas Liver- largest gland in your body Secretes bile- emulsifies fat, makes them water soluble. Stores glucose in the form of glycogen Makes clotting proteins Detoxifies blood
Gall bladder- stores and concentrates bile Pancreas- produces insulin, pancreatic juices amylase and lipase. Insulin regulates the uptake of glucose by the cells
Diseases Appendicitis Cholecystitis- gall bladder Cirrhosis- destruction of liver cells Diarrhea Diverticulitis Gasteroenteritis Hernia Pancreatitis Liver transplant Ulcer Colitis Bariatric surgery