Digestive System

Processing Food 4 Phases 1.Ingestion = food enters the mouth

Processing Food 4 Phases 2._________ = process that breaks food down into small molecules

Processing Food 4 Phases 2.Digestion = process that breaks food down into small molecules

Processing Food 4 Phases 2.Digestion = process that breaks food down into small molecules 2 types: Mechanical digestion = food is chewed and mixed in the mouth, churned in stomach and acted on by bile

Processing Food 4 Phases 2.Digestion = process that breaks food down into small molecules 2 types: Chemical digestion = breaks down large food molecules into smaller molecules that can be absorbed by cells; happens in mouth, stomach & small intestine

Processing Food 4 Phases 3.Absorption = small molecules of food are taken into the body cells

Processing Food 4 Phases 4.Elimination = wastes made of unabsorbed food molecules pass out of the body

Major Organs of Digestive Tract (food passes through) Mouth = digestion starts here

Major Organs of Digestive Tract (food passes through) Mouth = digestion starts here 1.Tongue & teeth mechanically break food up

Major Organs of Digestive Tract (food passes through) Mouth = digestion starts here 1.Tongue & teeth mechanically break food up 2.Saliva chemically digests food Saliva = mostly made of water, also contains mucus & ptyalin (an enzyme)

Major Organs of Digestive Tract (food passes through) Mouth = digestion starts here 3.Food is now a soft mass & is moved to the back of tongue and is swallowed When swallowing, a small flap of tissue called the epiglottis automatically closes over the trachea (windpipe)

Major Organs of Digestive Tract (food passes through) Mouth = digestion starts here 3.Food is now a soft mass & is moved to the back of tongue and is swallowed When swallowing, a small flap of tissue called the epiglottis automatically closes over the trachea (windpipe) 4.Food enters the food tube (esophagus)

Major Organs of Digestive Tract (food passes through) Esophagus

Major Organs of Digestive Tract (food passes through) Esophagus 1.Smooth muscles force food into the mucus-lined esophagus

Major Organs of Digestive Tract (food passes through) Esophagus 1.Smooth muscles force food into the mucus-lined esophagus 2.Rhythmic muscular contractions (peristalsis) push food downward

Major Organs of Digestive Tract (food passes through) Stomach

Major Organs of Digestive Tract (food passes through) Stomach 1.Food enters stomach 2.Cells in stomach release gastric juice that contains pepsin, hydrochloric acid (HCl) and mucus

Major Organs of Digestive Tract (food passes through) Stomach 3.Food undergoes mechanical digestion when stomach muscles churn the food

Major Organs of Digestive Tract (food passes through) Stomach 3.Food undergoes mechanical digestion when stomach muscles churn the food 4.Chemical digestion happens when hydrochloric acid (HCl) and pepsin break down the complex proteins

Major Organs of Digestive Tract (food passes through) Stomach 3.Food undergoes mechanical digestion when stomach muscles churn the food 4.Chemical digestion happens when hydrochloric acid (HCl) and pepsin break down the complex proteins 3.Peristalsis pushes the food toward stomach’s exit

Major Organs of Digestive Tract (food passes through) Small Intestine (6 meters long) 1.Most digestion happens here

Major Organs of Digestive Tract (food passes through) Small Intestine (6 meters long) 1.Most digestion happens here 1.Intestinal juice (full of enzymes) breaks down food

Major Organs of Digestive Tract (food passes through) Small Intestine (6 meters long) 3.Digestive Helpers a)Liver = bile is produced here b)Gall bladder = bile is stored here, then is released through the bile duct into the small intestine Bile breaks up fats (like dish detergent breaks up grease) c)Pancreas = produces pancreatic juices that are released into the small intestine to break down proteins, starches, & fats

Major Organs of Digestive Tract (food passes through) Small Intestine (6 meters long) 4.Digested food is absorbed through the villi into a network of blood vessels that carry the nutrients to all parts of the body

Major Organs of Digestive Tract (food passes through) Small Intestine (6 meters long) 4.Digested food is absorbed through the villi into a network of blood vessels that carry the nutrients to all parts of the body 5.By the time food leaves the small intestine, it is empty of all nutrients except water

Major Organs of Digestive Tract (food passes through) Large Intestine (1.5 meters long)

Major Organs of Digestive Tract (food passes through) Large Intestine (1.5 meters long) 1.Undigested food spends hours here & most of the water is absorbed

Major Organs of Digestive Tract (food passes through) Large Intestine (1.5 meters long) 1.Undigested food spends hours here & most of the water is absorbed 2.Helpful bacteria living in large intestine make vitamins K & B

Major Organs of Digestive Tract (food passes through) Large Intestine (1.5 meters long) 3.Materials not absorbed form into solid waste

Major Organs of Digestive Tract (food passes through) Large Intestine (1.5 meters long) 3.Materials not absorbed form into solid waste Solid waste = made of dead bacteria, some fat & protein, undigested food, dried out parts of digestive juices & old intestinal cells

Major Organs of Digestive Tract (food passes through) Large Intestine (1.5 meters long) 3.Materials not absorbed form into solid waste Solid waste = made of dead bacteria, some fat & protein, undigested food, dried out parts of digestive juices & old intestinal cells 4.Solid waste passes into the rectum and is stored until it is eliminated from the body through the anus

Digestive System Salivary Glands (yellow)Salivary Glands (yellow) Esophagus (pink) Stomach (purple) Liver (red) Small Intestine (green) Large Intestine (blue)