Portage Learning BIOD 151 A P1 Review Questions Module 3 Digestive System Overview

Portage Learning BIOD 151 A P1 Review Questions Module 3 Digestive System Overview Portage Learning BIOD 151 A P1 Review Questions Module 3 Digestive System Overview 1. Name the two main divisions of the digestive system organs.  Alimentary canal  Accessory digestive organs 2. Name the seven parts of the gastrointestinal tract. Oral cavity, pharynx, esophagus, stomach, small intestine, large intestine, anus 3. Name the six digestive system accessory organs. Teeth, tongues, salivary glands, liver, gallbladder, pancreas 4. Review all the figures and diagrams, including the GI tract and accessory organs. Anatomy of the mouth, pharynx & esophagus 5. What structures respectively form these parts of the mouth? a. Opening - lips b. Floor - tongues c. Walls - cheeks d. Roof - hard and soft palate *posterior border - uvula 6. List the two bones and the membrane to which the tongue is attached. Hyoid bone, mandible, lingual frenulum 7. How many teeth are there in an adult human and what do they do?32 chew food and prepares it for swallowing (tear, crush, and grind food to mechanically digest it) 8. What are the four types of teeth, how many of each type are there and what does each type do? Each jaw half has two incisors for biting, one canine for tearing, two pre molars for grinding, and three molars for crushing 9. What is the specific function of the salivary gland in the process of digestion? Release enzymes amylase which breaks down starches, therefore starts the process of chemical digestion 10. Where are taste buds located? Tongue, wall of pharynx, and surface of the mouth 11. Describe the function of the tongue in the digestive process. The tongue grips food and repositions it between the teeth to form the bolus. It also pushes the bolus back to the pharynx for swallowing. 12. What is a bolus? Food turned into a compact mass - it is formed by the combination of chewing by the teeth and repositioning by the tongue 13. List the 3 parts of the pharynx. nasopharynx, oropharynx, laryngopharynx 14. Through what sections of the pharynx does air travel? Through what sections of the pharynx does food travel? Air travels through all three sections, food travels through the oropharynx and laryngopharynx 15. What prevents food from entering the lungs and why is this necessary? Epiglottis, to prevent aspiration which could cause infection 16. Describe how the muscular layers in the pharynx assist with food passage. There is the circumferential outer layer and the longitudinal inner layer (both skeletal muscle)which contract alternatively causing peristalsis which squeezes food into the esophagus 17. List and describe the tissue layers of the esophagus. Mucosa - secretes mucus into the interior of the GI tractSubmucosa - contains blood and lymph vessels, lymph nodes, nerves and mucous glands Muscularis externa - is made up of two layers of muscle: outer longitudinal fibers and inner circumferential fibers Serosa - made up of cells that make serous fluid 18. Explain peristalsis. Involuntary contractions that move food along the GI tract. Alternating contractions of the sets of longitudinal and circumferential muscles. 19. What are the three main divisions of a tooth? Crown, neck, and root 20. What are the three types of papillae on the tongue? Which ones contain taste buds? Circumvallate, fungiform, and filiform. Circumvallate and fungiform contain taste buds. 21. Review all diagrams and figures in the module, including the teeth, tongue, taste buds, parts of the pharynx and esophagus. Anatomy of the stomach, intestines and accessory organs 22. Describe the shape of the stomach and its location relative to the abdomen and diaphragm. It is a backward C-shaped organ that is located along the left side of the abdomen below the diaphragm. 23. Describe the passage of food into and out of the stomach. Food enters the stomach from the esophagus via the cardiac sphincter and exits via the pyloric sphincter into the small intestine. 24. Describe the lesser curvature and the greater curvature. The stomach has two curvatures: the concave lesser curvature which extends inward on the shorter side of the stomach and the convex greater curvature which extends outward on the longer side of the stomach. 25. Describe the lesser omentum and the greater omentum. The lesser omentum attaches the lesser curvature of the stomach to the liver. The greater omentum hangs down and attaches the greater curvature of the stomach to the posterior wall of the abdomen, covering the transverse colon and anterior surface of the small intestines. They are a serous membrane called peritoneum. 26. List and describe the two functions of the stomach. 1. It is a temporary storage for food2. It does mechanical food breakdown by contracting vigorously and mixing food with juices 27. The pH of stomach is 1.3 - 3.5. What is this due to and what is its source and function? It is due to the secretion of HCl (secreted by parietal cells) which is essential for killing bacteria in food, deactivating amylase, and activating pepsin. 28. What is the source of the stomach enzyme pepsin and what is its function? The source of pepsin is pepsinogen, a pre-enzyme secreted by chief cells. The function of pepsin is the breakdown of proteins. 29. What is a stomach ulcer? It is an open sore in the wall caused by gradual disintegration of tissues 30. Explain in detail how the stomach contents enter the small intestine. At the base of the stomach is a narrow opening controlled by a valve called the pyloric sphincter. Relaxation of the sphincter causes a small quantity of chyme to pass through the opening into the duodenum, the first part of the small intestine. 31. List the 3 sections of the small intestine. Which section is the shortest? Duodenum (shortest), jejunum, ileum 32. What are the names of the valves which are located at the beginning and end of the small intestine? Pyloric sphincter and ileocecal valve 33. List the names of the 3 specialized structures in the wall of the small intestine. Circular folds, villi, and microvilli 34. Where is bile formed and stored? Formed in liver, stored in gallbladder. 35. Describe in detail the 2 major functions of pancreatic juice.  Contains sodium bicarbonate, which neutralizes chyme and makes the pH of the small intestine slightly basic.  Also contains digestive enzymes that act on the breakdown of food. 36. Describe how fats, sugars and amino acids are absorbed by the small intestine. Sugars and amino acids enter villi cells, and then are absorbed through the capillary beds present inside the villi. The nutrients are carried into the hepatic portal circulation beforeentering general blood circulation. Molecules that are too large to enter blood capillaries, such as glycerol and fatty acids, are transported into lacteals. 37. What are the 3 functions of the liver that are important in digestion? 1. Produces bile, which emulsifies fat 2. Stores glucose as glycogen and breaks down glycogen to glucose between meals to maintain a constant glucose concentration (homeostasis) 3. Produces urea from amino groups that are removed from excess amino acids 38. List the 8 regions of the large intestine. Cecum, appendix, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, anal canal 39. What are the two sphincters of the anal canal? Internal (involuntary smooth muscle) and external (voluntary skeletal muscle). 40. List 4 functions of the large intestine.  Propel wastes from the body  Reabsorb water  Reabsorbs electrolytes  Absorption of vitamin K and B produced from intestinal bacteria 41. What are the 2 major physiological problems caused by diarrhea? Dehydration, electrolyte loss 42. List the content of feces. 75% water, 25% solid matter. The solid matter is made up of intestinal bacteria, undigested plant materials, fats, waste products (bile pigments), inorganic material, mucus, and dead cells from intestinal lining. 43. Review all figures and diagrams, including all regions of the stomach, intestines, and accessory organs. Physiology of the GI Tract 44. Name the 4 main functions performed by the digestive system.Ingestion, digestion, absorption, defecation 45. What digestive system functions are carried out by the mouth? Ingestion and digestion starts at the mouth 46. Explain which digestive system functions are carried out by the stomach. Digestion (little to no absorption). The stomach’s main function is for mechanical and chemical breakdown of food. 47. Explain which digestive system functions are carried out by the small intestine. Digestion continues and absorption begins In the small intestine chemical digestion continues as enzymes from the pancreatic juices break down starches and proteins, and begin digestion of fat. Mechanical digestion continues as bile breaks down fat into smaller pieces. Absorption begins as digested food molecules, water and fat are absorbed into the bloodstream. 48. Explain the two main hormones that are responsible for hunger and satiety. Ghrelin and leptin. Leptin is produced by adipose tissue (fat cells). The role of leptin is to alert the brain to turn off the hunger center in the brain and activate the satiety center when consuming a meal. Ghrelin is produced by the stomach and has the opposite role. Ghrelin travels to the brain and stimulates the hunger center as it deactivates the satiety center. Ideally, leptin and ghrelin work together to balance hunger and satiety. 49. List the 5 biochemical materials needed by the body that are found in food. Carbohydrates, proteins, lipids, vitamins, and minerals 50. What are the 2 classes of carbohydrates and in what foods can each be found? Starches and sugars. Sugars - can be found in milk and fruits (ex. Apples, peaches). Starches - grains (ex. Wheat), vegetables (ex. Potatoes) 51. What are the 3 classes of lipids? Saturated fats, unsaturated fats, and cholesterol 52. What are the 2 classes of proteins and in what foods can each be found? Complete proteins - meats, eggs, poultry, dairy products, and soybeans Incomplete proteins - grains, legumes, seeds, and nuts 53. What is the definition of an essential amino acid, how many essential amino acids are there for adults and where can they be found?Amino acids required in an adult human diet. There are nine and can be found in complete proteins. 54. What are the 2 classes of vitamins? How is a vitamin different than a carbohydrate, lipid or protein? Why can ingestion of excessive amounts of one type of vitamin be dangerous? Water soluble and fat soluble. Vitamins are organic compounds that are not consumed in metabolic reaction but help enzymes carry out the metabolic reactions, which convert nutrients to materials needed by the body. Fat-soluble vitamins are stored in body fat, therefore if consumed in excessive amounts it can be problematic. 55. List 2 ways in which minerals are different than carbohydrates, lipids and proteins. List the seven minerals needed in the human diet and four foods which are good sources of these.  Minerals are inorganic compounds that, like vitamins, are not used as fuel in metabolic reactions but are combined with other nutrients to form necessary body substances.  No one food contains all the minerals that are needed by the human body.  Humans need the following 7 minerals: calcium, chloride, magnesium, phosphorous, potassium, sodium, and sulfur Physiology of the GI Tract Part II: Cellular Metabolism 56. Define anabolism. Anabolism is the set of reactions in which smaller molecules are combined to make larger, more complex molecules. 57. How is the energy released from the breakdown of glucose used by the body? It is used for the production of ATP (by adding a phosphate to an adenosine diphosphate (ADP) molecule) 58. Describe cellular respiration. Cellular respiration is defined as the process by which cells generate ATP. Glucose combines with oxygen to form carbon dioxide, water, and ATP. 59. Describe glycolysis. It is the breakdown of a single molecule of glucose into two pyruvate molecules, and two ATP molecules are formed. 60. Describe the citric acid cycle (TCA cycle).It is the central pathway of respiration and the pyruvic acid formed from glycolysis is converted into carbon dioxide forming ATP. It is a series of metabolic reactions that break down pyruvic acid to carbon dioxide and produces two more ATP and electron carriers called NADH and FADH2. 61. Describe the electron transport chain. Electrons are passed down a chain of electron acceptors causing protons to be bumped out of the membrane of the mitochondria. This causes a strong differential across the inner mitochondrial membrane, which forms a proton motive force. This force drives the protons back through the ATP synthase complex, resulting in the production of 34 ATP. In the electron transport chain hydrogen atoms formed during glycolysis and the TCA cycle are converted to water releasing energy which is used to add a phosphate to ADP to form ATP. 62. How is the energy released in the breakdown of glucose converted to a form usable by the cells? By forming 38 ATPs. The energy released in the breakdown of glucose allows the body to add a phosphate to an adenosine diphosphate (ADP) molecule and make adenosine triphosphate (ATP) which is the used by cells as a source of energy to perform cellular activities. 63. How does the energy formed in fat catabolism compare to that formed in carbohydrate metabolism? It forms twice as much ATP 64. Name, tell the location of and explain in detail the first stage of lipid breakdown. Occurs in the liver through a process called beta-oxidation. A fat molecule is broken down in the mitochondria to form acetic acid, which is further catabolized in the TCA cycle to carbon dioxide forming some ATP. 65. Why are proteins not usually used as a body energy source and when are they used? Proteins are the building blocks for cells and are saved as last resort (when carbohydrates and fats are unavailable to the body). 66. What is the first step in the oxidation of an amino acid formed from a protein? An amino group is removed from the protein to form ammonia when proteins must be used to form ATP. 67. Explain in detail how ammonia is removed from the body.It is combined with carbon dioxide in the liver to make urea, which is then excreted in urine. 68. Review all diagrams and figures.