Digestive system

Digestive system
 Enzymes: break-downs food substances
 Commands from the brain stem activates the production of saliva. Saliva contains enzymes that breakdown starches.
 Esophagus pushes food to the stomach using peristalsis.
 Stomach uses gastric juices and churning to further breakdown food.
 Peristalsis moves food from the stomach to the duodenum (small intestine)
 Acid food mixture becomes chemically alkaline from secretions of the pancreas, gallbladder, and small intestine wall.
 Additional enzymes and bile continue the food breakdown.
 Absorption occurs.
 Large intestine (mainly colon) continues absorption of water and passes the remaining waste to the rectum for excretion.
Disorders of the Digestive System
 Peptic ulcers – open sores in the stomach or duodenum. Causes by excessive gastric juices and bacterial infection.
 Hepatitis – liver becomes inflamed.
 Cirrhosis – liver cells die and are replaced by scar tissue. Caused by hepatitis and heavy alcohol consumption.
Disorders of these Systems - Diabetes
 Type I – insulin-dependent diabetes where person has to take exogenous insulin to make up for the lack of insulin produced by the pancreas.
 Type II – non-insulin dependent diabetes where body is not sufficiently responsive to insulin
 Leading cause of blindness in adults and 50% of dialysis patients (kidney failure) have diabetes.