Digestive System Questions Lecture 6 PDF

Questions lecture 6 Pt1 1. What is the main function of the digestive system? -The main function of the digestive system is to break down complex organic nutrient molecules into simple organic and inorganic molecules that can be absorbed into the blood or lymph to be tran...

Questions lecture 6 Pt1 1. What is the main function of the digestive system? -The main function of the digestive system is to break down complex organic nutrient molecules into simple organic and inorganic molecules that can be absorbed into the blood or lymph to be transported to cells. 2. What are the stages of digestion? -The stages of digestion are: 1. Ingestion or introduction of food and liquid into the oral cavity. 2. Mastication or chewing, which divides solid food into digestible pieces. 3. Motility includes muscular movements of materials through the tract. 4. Secretion of lubricating and protective mucus, digestive enzymes, acidic and alkaline fluids, and bile. 5. Hormone release for local control of motility and secretion. 6. Chemical digestion or enzymatic degradation of large macromolecules in food to smaller molecules and their subunits. 7. Absorption of the small molecules and water into the blood and lymph. 8. Elimination of indigestible, unabsorbed components of food. 3. What are the two main parts of the digestive system? The two main parts of the digestive system are: 1. The alimentary canal (gastrointestinal tract, GIT): It extends from the mouth to the anus. It consists of oral cavity, pharynx, esophagus, stomach, small intestine, and large intestine. 2. The accessory organs of digestion: include salivary glands, liver, gallbladder, and pancreas. 4. What are the two parts of the oral cavity? The two parts of the oral cavity are: 1. The vestibule of the mouth: the space lies outside the teeth and gums. 2. The mouth cavity proper: the space surrounded by the teeth and gums, hard and soft palates, and tonsils. 5. What are the three main parts of a tooth? The three main parts of a tooth are: 1. The crown: the visible part of the tooth. 2. The neck: present between the crown and root. 3. The root: extends into the bone and holds the tooth in place. 6. How many deciduous teeth does an individual develop? An individual develops a set of 20 deciduous teeth that begin to erupt at around 6 months of age and are usually complete by the age of 2 years. 7. How many permanent teeth does an individual develop? An individual develops a set of 32 permanent teeth, which includes 8 incisors, 4 canines, 8 premolars, and 12 molars. 8. What are the functions of the tongue? The functions of the tongue include chewing, speech, taste, and swallowing. 9. What are the two surfaces of the tongue? The two surfaces of the tongue are: 1. The lower (ventral) surface, which is smooth. 2. The dorsal surface, which is irregular and has hundreds of small protruding papillae and the massed lingual tonsils. 10. How much saliva is produced each day? The salivary glands collectively produce 1-1.5 liters of saliva each day. 11. What is the composition of saliva? Saliva is composed of 99.4% water, plus ions and enzymes. 12. What are the two types of salivary glands? The two types of salivary glands are: 1. The minor salivary glands, which are located in the oral mucosa and secrete about 10% of the total saliva volume. 2. The major salivary glands, which include the parotid, submandibular, and sublingual glands. 13. What are the three major salivary glands and where are they located? The three major salivary glands are: 1. The parotid glands, located just below and in front of the ears. 2. The submandibular (submaxillary) glands, located at the posterior corners of the mandible. 3. The sublingual glands, located below the floor of the mouth. 14. What percentage of saliva originates from each of the major salivary glands? Approximately 70% of saliva originates from the submandibular salivary glands, 25% from the parotid salivary glands, and 5% from the sublingual salivary glands. 15. What are the four main layers of the gastrointestinal tract wall? The four main layers of the gastrointestinal tract wall are: 1. Mucosa 2. Submucosa 3. Muscularis externa 4. Serosa 16. What are the three components of the mucosa layer? The three components of the mucosa layer are: 1_ Epithelial layer 2_ Lamina propria 3_ Muscularis mucosae 17. What is the function of the muscularis externa layer? The muscularis externa layer is responsible for the contractions that mix and propel the luminal contents forward. It is composed of an inner circular layer and an outer longitudinal layer of smooth muscle cells. 18. What is the role of the enteric nervous system in the digestive tract? The enteric nervous system, which comprises the plexus of nerves in the muscularis externa and submucosa, is responsible for generating and coordinating the contractions of the muscularis layer. 19. What is the purpose of the serosa layer? The serosa layer is a thin sheet of loose connective tissue that is rich in blood vessels, lymphatics, and adipose tissue. It covers the outer surface of the digestive tract within the abdominal cavity. 20. How long is the pharynx? The pharynx is a muscular tube that is approximately 5 inches in length. 21. How is the pharynx divided? The pharynx is divided into three parts: the nasopharynx, oropharynx, and laryngopharynx. 22. What is the function of the pharynx? The pharynx does not have a digestive function; its role is to allow the passage of air and food. 23. What is the purpose of the enamel layer of a tooth? The enamel is the hardest, white outer part of the tooth and serves to protect the underlying layers. 24. What is the function of the dentin layer of a tooth? The dentin is a layer of hard tissue that underlies the enamel and provides additional structural support and protection for the tooth. 25. What is the role of the pulp in a tooth? The pulp is the softer, living inner structure of the tooth that contains blood vessels and nerves. 26. What is the function of the cementum layer of a tooth? The cementum is a layer of connective tissue that binds the roots of the teeth firmly to the gums and jawbone. 27. What is the primary function of the teeth? The primary function of the teeth is chewing or mastication, which divides solid food into digestible pieces. 28. What is the purpose of the sulcus terminalis on the tongue? The sulcus terminalis is a V-shaped groove that separates the papillary and tonsillar areas on the dorsal surface of the tongue. 29. How many major salivary gland ducts are there? Each of the major salivary glands (parotid, submandibular, and sublingual) has at least one duct that takes saliva to the oral cavity. 30. What is the purpose of saliva production? Saliva has digestive, lubricating, and protective functions in the mouth.  Pt2 1. What is the main function of the stomach? Answer: The main functions of the stomach are temporary storage of ingested food, mechanical digestion with muscular contractions, and chemical digestion of food with acid and enzymes. 2. What is the average size of the stomach when empty? Answer: The size of the stomach is about 50 ml in its empty state. 3. What are the folds called in the stomach lining when the stomach is empty? Answer: The folds in the stomach lining when the stomach is empty are called rugae. 4. What is the semi-digested food in the stomach called? Answer: The semi-digested food in the stomach is called chyme. 5. What are the four major regions of the stomach? Answer: The four major regions of the stomach are the cardia, fundus, body, and pylorus. 6. Where is the cardiac sphincter located? Answer: The cardiac sphincter, or lower esophageal sphincter, is located at the bottom of the esophagus where it meets the stomach. 7. What is the function of the pyloric sphincter? Answer: The pyloric sphincter opens to allow partially digested food (chyme) to pass from the stomach into the duodenum. 8. What types of cells are found in the stomach mucosa? Answer: The types of cells found in the stomach mucosa are mucous cells, chief cells, parietal cells, and enteroendocrine G cells. 9. What is the function of the parietal cells? Answer: The parietal cells produce hydrochloric acid (HCl) and intrinsic factor, which is necessary for the absorption of vitamin B12. 10. What is the length of the small intestine? Answer: The small intestine is about 6 m in length. 11. What are the three segments of the small intestine? Answer: The three segments of the small intestine are the duodenum, jejunum, and ileum. 12. What is the function of the duodenum? Answer: The duodenum is involved in breaking down food and plays an important role in the absorption of nutrients. It also allows food to pass from the stomach into the small intestine. 13. What is the function of the jejunum? Answer: The jejunum is responsible for the absorption of important nutrients such as sugars, fatty acids, and amino acids. 14. What is the function of the ileum? Answer: The ileum is specifically responsible for the absorption of vitamin B12 and the reabsorption of conjugated bile salts. 15. What is the diameter and length of the large intestine? Answer: The large intestine is about 6.3 cm in diameter and 1.5 m in length. 16. What are the four parts of the large intestine? Answer: The four parts of the large intestine are the colon, cecum, rectum, and anus. 17. What is the function of the cecum? Answer: The cecum behaves as a receptacle for the liquids passed into the large intestine, is responsible for the absorption of salts and electrolytes, and is involved in lubrication and cellulose digestion. 18. What is the function of the appendix? Answer: The function of the appendix is unknown, but one hypothesis suggests that it acts as a storage area for beneficial bacteria. 19. What is the length and diameter of the rectum? Answer: The rectum is about 8 inches (20 cm) in length and 2.5 inches in diameter. 20. What is the weight and location of the liver? Answer: The liver is the largest internal organ, measuring about 1.5 kg or 2% of the body weight, and is located in the upper right and center of the abdominal cavity, just below the diaphragm. 21. How many lobes does the liver have? Answer: The liver consists of two large lobes, the right and left lobes. 22. What are the structural units of the liver called? Answer: The structural units of the liver are called liver lobules. 23. What do the sinusoids in the liver lobules receive blood from? Answer: The sinusoids in the liver lobules receive blood from both the hepatic artery and portal vein. 24. Where do the central veins of the liver lobules unite to form? Answer: The central veins of all the liver lobules unite to form the hepatic veins, which take blood out of the liver to the inferior vena cava. 25. What are the major histological components of the liver? Answer: The major histological components of the liver are the stroma (consisting of the capsule of Glisson) and the parenchyma (consisting of the hepatocytes). 26. What is the function of the cardiac sphincter? Answer: The cardiac sphincter (lower esophageal sphincter) allows food to pass from the esophagus into the stomach and prevents stomach acid from washing back up into the esophagus. 27. How does the size of the stomach change after a meal? Answer: After a meal, the size of the stomach can enlarge up to 1.5 L. 28. What is the function of the rugae in the stomach lining? Answer: The rugae in the stomach lining flatten out as the stomach is filled, allowing the lining to expand without tearing. 29. What is the pH of the gastric juice in the stomach? Answer: The gastric juice in the stomach has a pH of 1 to 2 due to the hydrochloric acid secreted by the parietal cells. 30. What is the function of the G cells in the stomach? Answer: The G cells in the stomach secrete the hormone gastrin, which stimulates the secretion of greater amounts of gastric juice. 31. Where does the small intestine begin and end? Answer: The small intestine extends from the stomach to the cecum of the large intestine. 32. What is the function of the ileocecal valve? Answer: The ileocecal valve prevents reflux of large intestine contents into the ileum during peristalsis. 33. What is the function of the haustra in the colon? Answer: The haustra, or sacs, in the colon wall give the colon its segmented appearance and are produced by the three separate longitudinal ribbons of smooth muscle called the teniae coli. 34. What is the function of the appendix? Answer: The function of the appendix is unknown, but one hypothesis suggests that it acts as a storage area for beneficial bacteria. 35. How many parts is the colon divided into? Answer: The colon is divided into four parts: the ascending colon, transverse colon, descending colon, and sigmoid colon. 36. What is the function of the liver in relation to the hepatic artery and portal vein? Answer: The sinusoids in the liver lobules receive blood from both the hepatic artery and portal vein. 37. What is the function of the capsule of Glisson in the liver? Answer: The capsule of Glisson, which is part of the liver's stroma, consists of connective tissue and contains the blood vessels. 38. What is the function of the hepatocytes in the liver? Answer: The hepatocytes, which make up the parenchyma of the liver, are the functional units responsible for the liver's many metabolic processes. 39. Where does the hepatic vein take blood from the liver to? Answer: The hepatic veins take blood out of the liver to the inferior vena cava. 40. What is the layer that covers the capsule of Glisson in the liver? Answer: The capsule of Glisson is covered by a layer of mesothelium.