Digestive System

Digestive System The functions of the digestive system are to take in food, break down food and absorb nutrients, and get rid of undigested material The digestive system includes: Mouth Pharynx Esophagus Stomach Small intestine Large intestine Rectum

Starting digestion Teeth break food into smaller pieces Saliva contains amylases that breakdown carbohydrates Passing of food through pharynx triggers a swallowing reflex

Getting food to the stomach Esophagus – connects mouth to stomach Uses smooth muscle contractions to push food down Peristaltic contractions

Digestion Takes Place in Stomach Food entering the stomach is regulated by the sphincter Prevents acid soaked food from re-entering the esophagus Gastric juices are secreted by cells that line the stomach Pepsin – breaks down proteins 2-6 hours for digestion Mucus protests the lining of the stomach

Small Intestine Duodenum receives secretions from the pancreas, liver , and gall bladder. Further digestion Bile secreted by the gall bladder breaks up fat Villi and microvilli increase surface area for absorption

The Large Intestine Food not absorbed (wastes) moves into the large intestive Contains dead cells mucus, digestive enzymes, bacteria, and yeast Bacteria synthesize some vitamins Aid in breaking down undigested materials Wastes are eliminated through the rectum

Liver Bile production Converts extra sugar to glycogen for storage Detoxifies the poisons in the blood

Disorders of the liver Peptic ulcer Appendicitis Gallstones Jaundice Cirrhosis of the liver