Digestive System

Purpose: –To break down food into useable molecules to be carried to the cells via our blood A.Mouth B.Esophagus C.Stomach D.Small Intestines E.Large Intestines Digestive Pathway (Path the food travels)

3 types of nutrients: Carbohydrates: -provide quick energy -must be digested into their simplest form/simple sugar molecule -bun Fats/lipids: -long term energy -must be digested -cheese and in red meat Protein: -build and maintain our cells and tissues -must be digested down into individual amino acids -cheese and red meat

1)Mouth-teeth physical digestion of all food types. 2) Salivary glands Produce saliva Empties into mouth Under the direction of your brain -how commercials workhow commercials work Produces the enzyme amylase Responsible for the chemical digestion of carbohydrates Digestive Pathway…..where food travels through. 3 ) Pharynx Back of throat area Common passage for -food and air No digestion occurs

Digestive System 4) Esophagus –Passageway for food from mouth to stomach –No digestion –peristalsis: Wave-like motion that pushes food to stomach animationanimation 5) Cardiac Sphincter –End of esophagus, beginning of stomach –Ring of muscle –Keeps food moving in 1 direction –What is “heart burn”? if food moves back into esophagus from sphincter. Contains acid from stomach

Digestive System 6) Stomach –Muscular sac which digests proteins –Physical digestion in form of churning –Chemical digestion in form of HCl, gastrin + pepsin to break down proteins –Special lining to protect from acid; “sore” in this lining can lead to an ulcer –Chyme- undigested food+enzyme+acid mixture.

Digestive System 7) Pyloric Sphincter –Ring of muscle which keeps food moving from stomach to sm. intestine 8) Small Intestine –~20-21 ft. long –3 sections –Duodenum: 1 st 10 inches, carries chyme to jejunum, is were all enzymes from pancreas and gall bladder empty into –Jejunum: 8 feet, carbs, proteins, lipids digestion; were food molecules are absorbed into blood –Ileum: 13 feet, takes undigested material to large intestine – Has villi

Villi in Small Intestine -Villi increases surface area of small intestines so more food can be absorbed into the blood faster.

Digestive System 9. Large Intestine/colon –larger in diameter –3 ft. long - removes excess water for undigested matter –too much water absorbed=constipation –too little water absorbed=diarrhea 10. Rectum & Anus –holds solid waste until expelled (rectum) –exit (anus)

animation

Organs part of the digestive system BUT not part of the digestive pathway.

1. Appendix Appendix- –No apparent function in humans –In other mammals, it helps to digest plant materials/cellulose –animationanimation

2. Liver: –Largest internal organ –Filters ammonia out of blood and converts it into urea –Makes bile 3. Gall bladder –Stores bile: for the digestion of lipids, empties into sm. Intestines via common bile duct. 4. Pancreas- makes and delivers the following to small intestines: –pancreatic amylase- carbs –lipase-lipids –trypsin- proteins –sends these enzymes to small intestine through the pancretic duct. –Sodium bicarbonate -is a base, neutralizes HCl so it does not damage small intestines.

To Digest… 1.Ingest 2.Chew 10 to 30 times 3.Swallow 4 to 8 seconds 4.Churn 2 to 4 hours 5.Absorb 3 to 5 hours 6.Compact 10 hours to several days! 7.Eliminate

The end………….

Digestive Problems Acid reflux Ulcer

Gall stones Made up of bile salts and cholesterol Appendicitis

Diverticulitis: Hemorrhoids