Post on 15-Dec-2015
DIGESTIVE SYSTEM
Objectives
• Describe digestion• Identify and explain the function of each organ of the system
• Explain preventative measures for digestive disorders
• Describe problems associated with the system
Functions of Digestive System• Digestion-mechanical and chemical breakdown of foods by the body’s cells
• Absorption-passage of digested food from digestive tract to the circulatory system
• Elimination-expulsion of undigested food or body waste
Structure of SystemMESSLA
• Mouth• Esophagus• Stomach• Small Intestine• Large Intestine• Anus• Organs that help-liver , gall bladder, pancreas
Mouth
• Ingestion: Taking of
food into the body•Structures are:
•Teeth: Break down food•Mastication: Process of chewing
•Salivary Glands: Saliva breaks down food, makes it easier to swallow
•Tongue: Prepares food to swallow
Esophagus
•Muscular tube extending from mouth to the stomach
•Peristalsis: Series of involuntary muscular contractions
Stomach
• Hollow, saclike organ enclosed in a muscular wall (3 layers of muscles)
• Function of the stomach is: • Continue to breakdown food
• Store food until it’s ready to enter small intestine
Stomach
• Control rate at which food enters small intestine
• Mix food and gastric juices (contain pepsin and hydrochloric acid) • Chyme: creamy fluid mix of food and gastric juices
Small Intestine
• Major part of digestion and absorption occur here
• 20-23 feet in length, 1 inch in diameter• Chyme enters small intestine and peristalsis moves it at a slow rate (3-5 hours)
• Villi: Fingerlike projections (Increase surface area) • Absorb digested food particles • Undigested food leaves as liquid and fiber
Large Intestine (Colon)
•Absorbs water and
eliminates undigested
food•5-6 feet in length,
2 ½ inches in diameter•Bacteria changes undigested food into feces
• Pancreas – produces the hormone insulin that regulates blood sugar levels
• -- also help neutralize stomach acid
• Liver – produces bile, which breaks down fats in foods
• Gallbladder – pouch-like
organ that stores bile for
future use
Digestive System Crash Course
https://www.youtube.com/watch?v=s06XzaKqELk
Care and Problems with the System• http://videos.howstuffworks.com/discovery-health/14062-b
ody-invaders-digestive-problems-video.htm
Problems with SystemFunctional Problems
• Indigestion• Heartburn• Gas• Nausea• Diarrhea• Constipation
Problems with SystemStructural Digestive problems• Gallstones-crystals that form in gall bladder.• Appendicitis-inflammation of appendix• Gastritis-inflammation of mucous membranes that line stomach
• Lactose Intolerance-inability to digest lactose• Peptic Ulcer-sore in lining of tract• Colitis-inflammation of colon• Hemorrhoids-swollen veins in lower rectum/anus• Tooth Decay
Care of the System
• Eat a variety of foods.• Avoid too many fatty foods• Choose foods low in fat and high in fiber• Do not hurry through meals• Do not wash food down with liquid• Drink plenty of water
1) Digestive System Worksheet
2) Choose one of the following and find a current event article:
• Celiac Disease• Diabetes• Crohn’s Disease• Peptic Ulcer• Diverticulitis
Fiber• Do you get yours?
http://kidshealth.org/teen/food_fitness/nutrition/fiber.html