check points chap 23 Wiley

Checkpoint Chapter 23
1. Give the name and function of each of the four layers if the GI tract. A. mucosa; inner surface for the secretion of digestive end products. B. submucosa: site of glands, blood vessels, lymph vessels and nerve plexuses. C. muscularis: circular and longitudinal muscles for propulsion and mixing. D. serosa: serous membrane to reduce friction with movement.
2. Where along the GI tract is the muscularis composed of skeletal tissue? Is control of this skeletal muscle, voluntary? A. mouth, pharynx, super4ior and middle parts if the esophagus and external anal sphincter. B. voluntary.
3. What are the attachment sites of the mesentery, mesocolon, falciform ligament, lesser omentum, and greater omentum? Mesentery – binds large intestine to posterior abdominal wall; falciform ligament – attaches liver to anterior abdominal wall and diaphragm; lesser omentum – suspends stomach and duodenum from the liver; greater omentum – from stomach and colon to transverse colon.
4. What are the functions of the myenteric and submucosal plexuses? A. myenteric plexus: innervates smooth muscle of muscularis. B. submucosal plexus: enervates secretory cells of mucosal epithelium to control the secretions of the organs of the GI tract.
5. Which structures form the mouth? Cheeks, hard and soft palate, tongue
6. What is the name of the cone shaped process that hangs down from the roof of the mouth? What is its function? Superior birder: a. uvula b. closes off nasopharynx during swallowing.
7. How are the major salivary glands distinguished on the basis of location? Parotid glands: located inferior and anterior to the ears, between the skin and masseter muscle; submandibular glands: located beneath the base of the tongue in the posterior part of the floor of the mouth; sublingual glands: superior to submandibular glands.
8. How is the secretion of saliva regulated? A. Via ANS: parasympathetic fibers increase salivation; sympathetic fibers decrease salivation. B. Feel and taste of food: smell, sight, sound, or thought of food.
9. Which functions to incisors, cuspids, premolars and molars perform? Incisors: grasping and tearing of food, cuspids: Tear and shredding of food; premolars: crushing and grinding; molars: crush and grind food in preparation for swallowing.
10. Define mastication using the term bolus. Chewing food until it is formed into a soft ball called a bolus for swallowing.
11. To which two organ systems does the pharynx belong? Respiratory and digestive
12. What does deglutition mean? Swallowing
13. What are the functions of the upper and lower esophageal sphincters? Upper esophageal sphincters: regulates movement of food from the pharynx into the esophagus; lower esophageal sphincters: regulates movement of food from the esophagus to the stomach.
14. What occurs during the oral, pharyngeal, and esophageal stages of swallowing? A. oral: voluntary passages of bolus into the oropharynx; b. pharyngeal: involuntary passage of bolus into the esophagus; c. esophageal: involuntary passage of bolus through the esophagus into the stomach.
15. Is swallowing voluntary or involuntary? Both; oral phase is voluntary, pharyngeal and esophageal phases are involuntary.
16. Does peristalsis “push” or “pull” food along the GI tract? Push
17. Which stomach layer is in contact with swallowed food? Mucosa
18. Which part of the stomach primarily serves as a food reservoir? Fundus
19. Which molecule is the source of the hydrogen ions that are secreted into gastric juice? Carbonic acid.
20. Which branch of the autonomic nervous system promotes digestion? Parasympathetic division.
21. What is the role of pepsin? Why is it secreted in an inactive form? A. break peptide bonds between amino acids. B. in the inactive form, form pepsinogen, it cannot digest the proteins in the chief cells that produce it.
22. Which substances are absorbed in the stomach? Water, ions, short-chain fatty acids, certain drugs.
23. What are the structures through which pancreatic juice might travel on its way to the duodenum? Exocrine cells to small ducts to large ducts to pancreatic duct and accessory duct: pancreatic duct joins common bile duct to form hepatopancreatic ampulla to sphincter of Oddi to duodenum.
24. What are the functions of the components of pancreatic juice? Digest carbohydrates, proteins, lipids and nucleic acids and to buffer acidity (bicarbonate ions).
25. How are protein-digesting enzymes in pancreatic juice activated? The brush border enzyme, enterokinase activates inactive typsinogen to the active protein trypsin; trypsin activates the other pancreatic proteases.
26. Which type of fluid is found in the pancreatic duct? The common bile duct? The hepatopancreatic ampulla? A. enzymes and bicarbonate ions. B. bile. C. pancreatic juices and bile.
27. What is the function of bile? Energy released from catabolic reactions is transferred to molecules of ATP and then used to power anabolic reactions.
28. The first few hours after a meal, how does the chemical composition of blood change as it flows through the livers sinuses? Oxygen, most nutrients and certain toxic substances are taken up by hepatocytes.
29. What are the regions of the small intestine in order from stomach to large intestine? What region is the longest? A. duodenum, jejunum, ileum. B. ileum
30. What purpose do the circular folds of the small intestine serve? Enhance absorption by increasing surface area and causing chime to spiral as it moves through the small intestine.
31. What are the functions of paneth cells? A. regulate microbial population in the intestines via lysozyme and phagocytosis. B. help neutralize gastric acids in chime.
32. What are the functions of segmentation and peristalsis in the small intestine? Of the fluid secreted by duodenal glands? Segmentation: mix chime with the digestive juices and bring food particles into contact with the mucosa for absorption; peristalsis: push chime forward done the small intestine.
33. Explain the function of pancreatic amylase, brush border enzymes, pancreatic lipase and deoxyribonuclease. Pancreatic amylase: chemically break down gylycogen and starches; brush border enzymes: chemically break down disaccharides into monosaccharides; pancreatic lipase: break down triglycerides into fatty acids and monoglycerides: deoxyribonuclease: digest DNA.
34. Why are bile salts needed for lipid digestion? To emulsify fats.
35. How are the end products of carbohydrates protein, and lipid digestion absorbed? A. Carbohydrate end products: by facilitated diffusion or secondary active transport into blood; b. protein end products: by active transport process into blood; lipids: by simple diffusion into lacteals (lymph system).
36. Why are triglycerides circulated through the body in chylomicrons? The hydrophilic protein that surrounds each chylomicron keeps it suspended in blood and prevents them from sticking to each other.
37. By which route do absorbed nutrients reach the liver? Via the hepatic portal system, (all absorbed nutrients except triglycerides) or via the lymphatic vessels to the blood vascular system and then to the liver (triglycerides).
38. What are the major regions of the large intestine? Cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, anal canal, and anus.
39. What is the function of the goblet cells in the large intestine? Secrete mucous that lubricates the passage of colonic contents.
40. How does mechanical digestion occur in the large intestine? Through haustral churning, peristalsis, and mass peristalsis.
41. Which primary activity occurs in the large intestine to change contents to feces? Water absorption.
42. What is the result and purpose of the cephalic phase of digestion? Result: activation of neural centers in the cerebral cortex; Purpose: To prepare the mouth and stomach for food that is about to be eaten.
43. Why does food initially cause the pH of gastric juice to rise? It buffers the stomach acid.
44. Why is stomach activity inhibited during the intestinal phase of digestion? It prevents the duodenum from being over loaded with more chime than it can handle.
45. Explain the role of cholecystokinin and secretin in the intestinal phase of digestion. Cholecystokinin stimulates secretion of pancreatic juice rich indigestive enzymes, causes ejection of bile from the gall bladder, causes opening of the sphincter of the hepatopancreratic ampulla, induces satiety, and inhibits gastric emptying; secretin stimulates secretion of pancreatic juice and bile that are rich in bicarbonate ions and inhibits secretion of gastric juice.
46. What is metabolism? What is the difference between anabolism and catabolism? A. All the chemical reactions of the body. B. anabolism: chemical reactions that combine simple substances into more complex molecules. C. Catabolism: chemical reactions that break down complex organic molecules into simpler ones.
47. How does ATP link anabolism and catabolism? When complex molecules and polymers are split apart, some of the energy is transferred to form ATP and the rest gives off heat; when simple molecules and monomers are combined, to form complex m molecules, ATP provides the energy for the synthesis and again, some energy is given off as heat.
48. Which components of cellular respiration produce ATP during the complete catabolism of a molecule of glucose? How many molecules of ATP are produced? A. glycolysis, Krebs cycle, electron transport chain; b. 36 or 38.
49. What happens during glycolysis? In the electron transport chain? A. Glucose is catabolized into 2 pyruvic acid and results in the production of two ATP molecules and 2 NADH+H2 molecules, b. 32-34 ATO molecules are formed from the energy contained in the NADH+H2 and FADH molecules.
50. What is gluconeogenesis and why is it important? Glucose is formed from noncarbohydrate sources which helps maintain normal blood glucose levels between meals.
51. What are the functions of proteins in lipoproteins? Which lipoprotein particles contain “good” and “bad” cholesterol, and what are the meanings of these terms? A. transport lipids in blood by making them temporarily water soluble. B. “good” cholesterol: HDL c. Bad cholesterol: VLDL and LDL d. HDL: high-density lipoprotein (higher percentage of protein, lower percentage of lipids); LDL Low density lipoprotein, (low percentage of protein and higher percentage of lipids); VLDL: very low density lipoprotein: lowest of protein and highest percentage of lipids.
52. What does the MyPlate icon tell you about a healthy diet? Each meal should be half fruits and vegetables with a bigger serving of vegetables, half grains and proteins with a bigger serving of grains and include dairy.
53. Briefly describe the functions of the following minerals: calcium, iron, magnesium, manganese, sodium, and phosphorous. Calcium, iron, magnesium, and manganese are important in enzyme reactions. Sodium and phosphorous are important as components in buffer systems; sodium is important in water regulation and neural functions.
54. What us a vitamin? What is the general function of vitamins? How do we obtain vitamins? A. organic nutrients required in small amounts to maintain growth and normal metabolism. B. function as enzymes. C. ingested in food except for vitamins K and B complex vitamins which are synthesized by bacteria in the large intestines.
55. How are fat soluble and water soluble vitamins different? Fat soluble along with other dietary lipids in the small intestines and packaged into chylomicrons; Water soluble are dissolved in body fluids.
56. Which functions are served by antioxidant vitamins? They inactivate oxygen free radicals, possibly protect against some cancers, reduce the buildup of plaque and delay some effects of aging.