Unit 6 Lesson 4 Digestive System Animation on diges tion for children John Levasseur Springfield Central High School Based on PowerPoint Presentation found at: http://sun.menloschool.org/~cfat/powerpoint/biology/index.html Questions to Ponder from Lesson 3
What are the parts of a human heart? Check your knowledge of the heart at this site: http://www.kscience.co.uk/animations/heart_labelling.htm What are the parts of human lungs? Check your knowledge of the Lungs at this site: http://www.kscience.co.uk/animations/lungs.swf What is the purpose of the circulatory system? What is the purpose of the circulatory system? What is the purpose of the respiratory system? What are the more scientific names for red and white blood cells? What blood vessel takes blood away from the heart? What blood vessel returns blood to the heart? What part of the heart receives blood and what part actually pumps blood? What part of blood is responsible for clotting? What is the function of capillaries? What is the function of alveoli? What is the function of the epiglottis? MA Framework for Digestive System 4.1 Digestive System Explain generally how the digestive system converts
macromolecules from food into smaller molecules that can be used by cells for energy and for repair and growth. Know the digestive systems key structures form and functions: mouth, pharynx, esophagus, stomach, small and large intestines, rectum. Digestive System The digestive system purpose is to breakdown the food that we eat into the molecules that can be absorbed by our bodies for nutrition. The digestive system consists of two sets of organs and body structures: The digestive tract (alimentary canal) and the accessory digestive structures.
The digestive tract is the passage way made of the digestive systems organs that passes through the body starting at the mouth and ending with the anus. Accessory digestive system structures would include: the teeth, tongue, epiglottis and the glands that produce the enzymes need for digestion. Introduce yourself to the structures of the digestive system: http://www.innerbody.com/anim/mouth.htm Digestive System (cont.) View this video at: http://health.howstuffworks.com/adam-200142.htm View this interactive animation of digestion:
http://kitses.com/animation/swfs/digestion.swf Digestive Juices, Enzymes and Acid Food is broken down for absorption by the body two ways: mechanically and chemically. Mechanical breakdown of food includes chewing in the mouth and segmentation during peristalsis. Chemical break down is done by enzymes and acids produced in glands along the digestive tract. The digestive glands that act first are in the mouththe salivary glands. The next set of digestive glands is in the stomach lining. These glands produce stomach acid (HCl) and an enzyme that digests protein. After the stomach empties the food and juice mixture into the small intestine, the juices of two other digestive organs mix with the food. One of these organs, the pancreas, produces a juice that contains a wide array of enzymes to break down the carbohydrate, fat, and protein in food. Other enzymes that are active in the process come from glands in the wall of the intestine.
The liver, produces yet another digestive juicebile. Bile is stored between meals in the gallbladder. At mealtime, it is squeezed out of the gallbladder, through the bile ducts, and into the intestine to mix with the fat in food. The bile acids dissolve fat into the watery contents of the intestine, much like detergents that dissolve grease from a frying pan. After fat is dissolved, it is digested by enzymes from the pancreas and the lining of the intestine. Text From: http://digestive.niddk.nih.gov/ddiseases/pubs/yrdd/ Animation on Food to Fuel The Mouth and Swallowing The breakdown of food into digestible molecules begins in the mouth. Food is ground by chewing and moistened by saliva. Saliva also begins the chemical breakdown of food with an enzyme for hydrolysis of complex sugars amylase. Chewing Mechanical breakdown by grinding and tearing of food.
Saliva A liquid secretion into the mouth that contains enzymes which start the chemical breakdown of food. Bolus After chewing, food is shaped into a ball (bolus) and forced into the pharynx by the tongue. The Mouth and Swallowing (Cont,) Epiglottis When we swallow a flap of skin called the epiglottis covers the trachea preventing food from going into the lungs.
Esophagus The canal from the pharynx to the stomach is called the esophagus. Food moves down the esophagus by peristalsis, the involuntary contraction of the smooth muscle Watch this animation on swallowing: http://health.howstuffworks.com/ adam-200089.htm Peristalsis Peristalsis is the rhythmic contraction of smooth muscles to propel contents through the digestive tract. After food is chewed into a bolus
and swallowed into the esophagus smooth muscles will contract behind the bolus to prevent it from being squeezed back onto the mouth. Rhythmic waves of contractions work to rapidly force the food into the stomach. This process works in one direction only and its sole purpose is to move food from the mouth into the stomach. A peristaltic wave pushes the bolus through the esophagus into the stomach. The wave travels down to the stomach even if the bolus of food descends at a greater rate than the wave itself, and will Text from: continue even if for some reason http://en.wikipedia.org/wiki/Peristalsis Stomach
The stomach is found under the diaphragm in the upper part of the abdominal cavity. Food enters the stomach after having been chewed, swallowed, and passed through the esophagus. The stomachs size can change dramatically with the amount of food being stored. The cardiac sphincter is a ring of muscle that prevents food from reentering the esophagus while the stomach is contracting to form a semisolid mixture known as chyme. The pyloric sphincter separates the small intestine from the stomach.
http://www.acm.uiuc.edu/sigbio/project/digestive/middle/ Stomach (cont.) http://www.acm.uiuc.edu/sigbio/project/digestive/middle/stomach.html The stomach functions as a pouch to receive the chyme where more mechanical and chemical breakdown can take place. In the stomach hydrochloric acid and protein digesting enzymes mix with the food to continue the process of preparing the food for absorption into the blood stream. There are three layers of smooth muscle that run lengthwise,
around making the stomach one of the strongest internal organs. The folds in the lining of the stomach are known as rugae secrete gastric juice and hydrochloric acid. Small Intestine The small intestine is the largest part of the digestive system and is the key organ of this system. The small intestine is composed of three sections: duodenum (1foot long) jejunum (5-8 feet long) ileum (16-20 feet long). In the small intestine nutrients from food are absorbed into the blood stream via osmosis.
To pass through the small intestines wall, food particles must be broken down to the level of molecules. Complex sugars to Monosaccharides Proteins into simple peptides or amino acids Fats into simple lipid compounds Duodenum and Bile The duodenum is the portion of the small intestine where different enzymes are added to the digesting food, (chyme). Remember enzymes control chemical reactions in living things. The names of enzymes end with the letters "ase". The small intestine secretes sucrase (breaks sucrose into glucose and fructose); maltase (breaks maltose into glucose); and lactase (breaks lactose into glucose and galactose, lactase is missing in a good percentage of people). Another enzyme
secreted into the duodenum is petidase used to split peptides (from proteins) into amino acids, and lipase to break down fat into glycerol and fatty acids. Text from: http://www.becomehealthynow.com/mira2_front/printpage.php?id=730 The duodenum receives bile from the liver and gallbladder. Bile decreases the surface tension between large fat globules and water, and break lipids into smaller globules that can be acted upon by lipase, amylase, trypsin, chymotrypsin and sodium bicarbonate are received from the pancreas upon hormonal signals from pancreozymin and other hormones (produced in the small intestine) and neural signals from the vagus nerve. Small Intestine Images
Large Intestine The Large Intestine is also known as the colon. There are four sections to the large intestines: Ascending colon Tarnsverse colon Descending colon Rectum The large intestine begins at the end of the small intestines and ends at the rectum The large intestine absorbs water from the chyme and feces
Digestive System Review A. B. C. D. E. F. G. H. I. J. K. L. See Animation Questions to Ponder from Lesson 4
What is the purpose of the digestive system? How is mechanical breakdown of food accomplished? How is chemical breakdown of food accomplished? What is peristalsis? Where in the digestive tract are nutrients absorbed into the blood stream? Where in the digestive tract is water reabsorbed into the body? What is the function of the liver? What is the function of the stomach? What is the function of the small intestine? What is the function of the colon? What is the function of the gall bladder? What is the function of bile? What is the function of enzymes? What is a bolus? What is the acid found in stomach?
Times New Roman Arial Times Tahoma Wingdings MS Pゴシック orange_10-08 Food Choices and Sensory Characteristics Questions to Ponder Factors Affecting Patterns of Eating Family and Social Cultural Religious Beliefs Nutrition and Health Economic and Marketplace Factors Technological Development Emotional and...
Outcome measures: Two quantitative outcome measures used pre and post group. Illness cognitions questionnaire (Evers & Kraaimat, 1998): 18 item questionnaire measuring hopelessness, acceptance and perceived benefits of illness Quality of Life measure Qualitative feedback is obtained pre and post...
The range of multicast addresses in IPv6 is larger than in IPv4. For the foreseeable future, allocation of multicast groups is not being limited. IPv6 also defines a new type of address called an anycast address. An anycast address identifies...
Vowels. During vowel productions, the articulators do not come very close together, so the airstream is relatively unobstructed. Are classified along two dimensions: Fronting/Backing. (front/center/back) - How far forwards or back is the tongue? Tongue Height. (high/mid/low) - How much...
La antigüedad: años 60 Ivan Sutherland, estudiante del MIT, realiza su tesis doctoral en la aplicación de los gráficos por computador al diseño en la ingeniería: el proyecto se llamó Sketchpad, y se considera el inicio de la industria del...
Las listas están divididas en 4 categorías, Las de más alta resistencia al viento, las de media-alta resistencia, las de media-baja y las de más baja resistencia para dicotiledoneas, coníferas, palmas y árboles frutales. Luego, se presentan fotografías para las...