HUMAN SYSTEMS Digestive System DIGESTIVE SYSTEM Digestion Absorption

HUMAN SYSTEMS: Digestive System

DIGESTIVE SYSTEM � Digestion � Absorption � Assimilation

DIGESTIVE SYSTEM � Made up of tube like organs called digestive tract � Mouth, pharynx, esophagus, stomach, small and large intestines, rectum and anus � Salivary gland, liver, pancreas, and gall bladder also contribute but food does not pass through them

DIGESTIVE SYSTEM � Breaking down food �Mechanical �Chemical � Carbohydrates, � Enzymes proteins, fats for digestion

DIGESTIVE SYSTEM � Digestion begins in mouth � � Teeth (enamel) Role of saliva

DIGESTIVE SYSTEM � Leaving the mouth �Esophagus �peristalsis �antiperistalsis

DIGESTIVE SYSTEM � Stomach � Muscular sac- like organ � Squeeze food � Acid and enzymes for digestion � Acid kills microbes as well � Leaving the stomach � Chyme (chyme is acidic) � Stomach releases chyme into small intestine

DIGESTIVE SYSTEM � Pancreas Produce secretions to reduce acidity (bicarbonate) � Produce digestive enzymes � Chyme does not enters the pancreas �

DIGESTIVE SYSTEM � Small intestine Muscular long tube � Villi increase surface area, facilitate absorption �

DIGESTIVE SYSTEM � Liver and gall bladder � Breaks down toxins, stores materials, produce bile � Bile is made by liver, stored in gall bladder, secreted in small intestine � Role in fat digestion

DIGESTIVE SYSTEM � Large intestine � Stores, compacts and eliminates undigested material � Absorption of water � Undigested waste – feces or stool � Stored in last part of intestine – rectum � Excreted through anus � Fiber and digestion

DIGESTIVE SYSTEM

DISORDERS � Ulcers � Liver disorders (infections and cancer) � Diarrhea and constipation � Appendicitis � Colon cancer