(A) Diarrhea. (B) Stomach cramps. (C) Dehydration due to excess fluid loss. (D) A, B, and C are correct. (E) Only answer B is correct.

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1 Human Anatomy - Problem Drill 21: The Digestive System Question No. 1 of A 26-year-old male is treated in the emergency department for severe gastrointestinal disturbance. Which of the following symptoms are possible? Question #01 (A) Diarrhea. (B) Stomach cramps. (C) Dehydration due to excess fluid loss. (D) A, B, and C are correct. (E) Only answer B is correct. Diarrhea is possible due to inefficient water reabsorption. Stomach cramps are possible, but this is not the only correct answer. The loss of fluid from decreased reabsoprtion can lead to dehydration. D. Correct! Diarrhea, stomach cramps and dehydration are all possible with gastrointestinal disturbance. Answers A and B are also correct. The digestive system involves many specialized organs that have both distinct and overlapping functions. The digestive system, or alimentary canal, is responsible for the breakdown of materials, for the absorption of nutrients and water, as well as for the temporary storage and elimination of waste from the body. (D)A, B, and C are correct.

2 Question No. 2 of A biopsy sample of the stomach is prepared for histological study. Which of the following microscopic findings is correct: Question #02 (A) There is evidence of cell necrosis in the pyloric region at the junction between the esophagus and the stomach. (B) There is evidence of cell necrosis in the cardia region at the junction between the esophagus and the stomach. (C) All 6 muscle layers in the stomach look normal. (D) There is evidence of infiltrating immune cells in the duodenum. (E) The biopsy sample is normal, including the fact that there is no submucosa, which is to be expected in the stomach. The pyloric region of the stomach is near the junction of the stomach and the small intestine. B. Correct! The cardia region is at the junction of the esophagus and stomach. The stomach has 3 muscle layers. The duodenum is not part of the stomach; rather it is the first section of the small intestine. The histology of the stomach includes a submucosa, underneath the mucosal layer. The stomach can be divided into key regions: The cardia is where the esophagus contacts the stomach. The fundus is a storage area of the stomach; food can remain in this region for up to an hour prior to mixing with gastric juices. Food mixes with gastric juices in the pyloric region. The stomach has a unique arrangement of three muscular layers: an outer longitudinal layer, a circular layer underneath, and an oblique layer on the inside. This 3-layer setup allows the stomach to contract in a wide variety of directions to break up food into small particles. (B)There is evidence of cell necrosis in the cardia region at the junction between the esophagus and the stomach.

3 Question No. 3 of During a physical exam, the physician notes a key finding in the abdominal region. The physician records that the abnormality is on the right side of the patient and its source is intraperitoneal. Which of the following organs is likely involved: Question #03 (A) Pancreas. (B) Stomach. (C) Liver. (D) Pancreas or liver. (E) Sigmoid region of the large intestine. The pancreas is more midline, extending to the left side of the body, and has a portion that is secondarily retroperitoneal. The stomach is located from the left side of the body towards the midline. C. Correct! The liver is located on the right side of the body and is intraperitoneal. The pancreas is more midline, extending to the left side of the body, and has a portion that is secondarily retroperitoneal. The sigmoid colon is located on the left side of the body. The peritoneum is a serous membrane that lines the abdominal cavity. Within the peritoneal cavity, the organs are divided into 3 main regions: (1) Intraperitoneal e.g., the stomach and liver, (2) Retroperitoneal kidneys and ureters, and (3) Secondarily retroperitoneal pancreas. (C) Liver.

4 Question No. 4 of A 25-year-old man is referred to an Ear, Nose and Throat (ENT) doctor. During the examination, the ENT notes a problem in the location marked by the arrow on the diagram below. What part of the oral cavity is the mark identifying? Question #04 (A) Soft Palate. (B) Hard Palate. (C) Base of the tongue. (D) Oropharynx. (E) Epiglottis. A. Correct! The arrow is pointing to the soft palate in the oral cavity. The hard palate is located in front of the soft palate. The base or root of the tongue is more inferior, located in the bottom half of the mouth. The oropharynx is located inferiorly, near the epiglottis. The epiglottis is located inferior to the oropharynx. The soft and hard palate form the roof of the oral cavity, and the tongue forms the floor. The hard palate separates the oral and nasal cavities. The soft palate separates and closes off the nasopharynx during swallowing. (A)Soft Palate.

5 Question No. 5 of During a fluoroscopic swallow test, an abnormality is noted in one of the swallowing phases. Which of the following is correct? Question #05 (A) The food bolus moved irregularly during the oral phase as it passed through the lower esophageal sphincter. (B) During the pharyngeal phase, there was a problem with the closure of the epiglottis. (C) During the pharyngeal phase, there was a problem as the bolus moved up towards the hard palate. (D) The abnormality was detected in the esophageal phase as the bolus entered the pharynx. (E) All 5 phases of swallowing were normal; the lower esophageal sphincter action was abnormal. During the oral phase, the food bolus does not pass the epiglottis. B. Correct! The epiglottis does close off the airway for swallowing and it is during the pharyngeal phase. At the beginning of the pharyngeal phase, the food bolus has already left the oral cavity. The food bolus is in the esophagus during the esophageal phase of swallowing. Swallowing in humans is divided into 3 phases. Swallowing is a complex event that is coordinated by the swallowing center in the lower portion of the brainstem. During this process, food passes from the mouth to the pharynx and into the esophagus; this occurs in three phases: (a) oral phase (b) pharyngeal phase and (c) esophageal phase. (B)During the pharyngeal phase, there was a problem with the closure of the epiglottis.

6 Question No. 6 of A 33-year-old woman complaining of painful swallowing is found to have a lump on a physical exam. Her physician orders a barium swallow to visually assess the esophagus. Which of the following statements is correct? Question #06 (A) The esophagus is normal in appearance, including the fact that there is no submucosa in this region of the digestive tract. (B) The size of the esophagus is normal, approximately 25 cm in length and 2 cm in diameter. (C) The esophagus is in its normal location of the peritoneal cavity. (D) The size of the esophagus is normal, approximately 45 cm in length and 6 cm in diameter. (E) As expected, there are no esophageal folds made up of the mucosa and submucosa. The esophagus has both mucosa and submucosa. B. Correct! The size of the esophagus is approximately 25 cm in length and 2 cm in diameter. The esophagus passes through the diaphragm and enters the abdominal cavity. The size of the esophagus is approximately 25 cm in length and 2 cm in diameter. The esophagus does have esophageal folds made up of mucosa and submucosa. The esophagus is a hollow, muscular tube that delivers food from the oral cavity into the stomach through the lower esophageal sphincter. It is approximately 25cm (12 inches) in length and about 2cm in diameter. The wall of the esophagus has the following layers: (A) Mucosa includes an abrasion epithelium, (B) Esophageal folds made up of mucosa and submcosa, they allow for expansion, (C) Smooth muscle layer, (D) Esophageal glands produce mucous for lubrication, and (E) Muscularis externa contains circular and longitudinal involuntary muscle layers. (B)The size of the esophagus is normal, approximately 25 cm in length and 2 cm in diameter.

7 Question No. 7 of Which part of the oral cavity is marked by the arrow in the diagram below? Question #07 (A) Parotid gland. (B) Parotid duct. (C) Sublingual gland. (D) Submandibular gland. (E) Anterior parotid gland. The parotid gland is in front of and below the ear. The parotid duct extends in front of the parotid gland. C. Correct! The arrow is pointing to the sublingual gland. The submandibular gland is located towards the back of the tongue. There is only one parotid gland, located in front of and below the ear. Each of the three salivary glands produces slightly different saliva and secretes it into the oral cavity. Saliva is made up of water plus a small amount of ions, buffers, metabolites and enzymes. The parotid glands are the largest salivary glands and are located in an area posterior to the mandibular ramus, anterior and inferior to the ear. The sublingual glands are located underneath the mucous membrane of the floor of the mouth. The submandibular glands are located in the floor of the mouth, along the medial surfaces of the mandible. These glands contribute approximately 70% of the saliva in the mouth. (C)Sublingual gland.

8 Question No. 8 of A 51-year-old male is sent for pancreatic function testing because his physician suspects pancreatitis. Which of the following statements about the function of the pancreas is true? Question #08 (A) The pancreatic duct that delivers pancreatic enzymes runs from the gallbladder past the pancreas into the small intestine. (B) The glucagon and insulin produced by the pancreas are delivered into the small intestine during digestion. (C) Hydrochloric acid, trypsinogen, and amylase are produced by the pancreas and function during digestion. (D) The pancreas releases precursor enzymes, which are converted to their active forms in the intestine. (E) The pancreatic duct delivers pancreatic enzymes from the head of the pancreas towards the tail of the pancreas, which is nearest the small intestine. The pancreatic duct originates in the pancreas and joins the common bile duct from the gallbladder. Glucagon and insulin are part of the endocrine function of the pancreas and are, therefore, released directly into the bloodstream. The pancreas does not produce hydrochloric acid; this is produced in the stomach. D. Correct! The pancreas does release its enzymes in a precursor form, which are converted to their active forms in the intestine. The head of the pancreas is nearest the small intestine; the tail is at the opposite end of the organ. The pancreas is an elongated organ, adjacent to the stomach and in close association with the first segment of the small intestine, the duodenum. The pancreatic duct runs along the length of the pancreas and enters the duodenum, which delivers the pancreatic enzymes for digestion. The enzymes produced in the pancreas are released into the duodenum in their precursor form. Once they are in the small intestine, they are converted into their active forms. The pancreatic enzymes are released from the pancreas in response to the hormones, gastrin, secretin and CCK. (D)The pancreas releases precursor enzymes, which are converted to their active forms in the intestine.

9 Question No. 9 of If a patient was diagnosed as having problems with muscular function in their digestive system, which of the following statements about muscular control in the digestive system would be true? Question #09 (A) The digestive system is innervated by the enteric nervous system. (B) The central nervous system has no control or impact on the digestive system. (C) The enteric nervous system is made up of the myenteric plexus and the peripheral nervous system. (D) All of the innervation of the digestive system lies within the submucosa. (E) Only the longitudinal muscle layer is innervated. A. Correct! The digestive system is innervated by the enteric nervous system. The central nervous system inputs control on the digestive system, which can also be operated independently by the enteric nervous system. The enteric nervous system is made up of the myenteric plexus and the submucosal plexus. The innervation of the digestive system lies in two locations: (1) between the circular and longitudinal muscle layers, and (2) between the layer of the circular muscle and the submucosa. All muscle layers of the digestive system are innervated. The digestive system is innervated and controlled by the enteric nervous system. While the central nervous system inputs control on the enteric nervous system, the enteric nervous system can operate independently. The enteric nervous system is composed of two layers: (a) Myenteric plexus, which lies between the circular and longitudinal muscle layers, and (b) Submucosal plexus, which lies between the layer of circular muscle and the submucosa. (A)The digestive system is innervated by the enteric nervous system.

10 Question No. 10 of An 81-year-old woman goes to her doctorʹs office because of general digestive disturbance. The doctor informs the patient that the digestive system can change with age. Based on the effect of aging on the digestive system, which of the following statements is true? Question #10 (A) While muscular action can decline with age, digestion and absorption can remain normal. (B) One of the changes of the digestive system with aging can be an increase in the rate of stem cell division. (C) The striated muscle action of the intestinal wall can decrease. (D) The one organ in the digestive system that will not change based on the aging process is the liver. (E) Diverticulitis and hemorrhoids occur due to the fact that the rate of epithelial stem cell division decreases with age. A. Correct! Digestion and absorption can occur normally in elderly individuals, while other aspects of the digestive system can decline. With age, the rate of epithelial stem cell division decreases. The smooth muscle action of the intestinal wall can decrease with age. The liver is impacted by the exposure to drugs and chemicals over time as we age. Diverticulitis and hemorrhoids can occur because of a decrease in smooth muscle action in the digestive system. As we age, digestion and absorption occur similarly as in our youth. However, there are some physical changes that take place as we age: (1) The rate of epithelial stem cell division decreases. As a result of the slowdown of replacement cells, the risk of injury and ulceration increases, (2) Smooth muscle action decreases; there is a decrease in the motility and muscle tone. This can lead to diverticulitis, hemorrhoids, and esophageal reflux, and (3) Cumulative damage effects chronic exposure to toxins and viruses, for example, that are absorbed and processed in the liver can lead to liver disease and cirrhosis. Also, the rate of colon and stomach cancer increases with age. (A)While muscular action can decline with age, digestion and absorption can remain normal.