Nokea
The term gastrointestinal (GI) tract refers to the
- A. oral cavity, pharynx, esophagus, stomach, small intestine and large intestine.
- B. pharynx, esophagus, stomach, small intestine and large intestine.
- C. esophagus, stomach, small intestine and large intestine.
- D. stomach, small intestine and large intestine.
Correct Answer: A
Rationale: Step 1: The GI tract starts from the oral cavity where digestion begins.
Step 2: It then moves to the pharynx, esophagus for food transport.
Step 3: Next, the food enters the stomach for further digestion.
Step 4: The small intestine is where most digestion and absorption occur.
Step 5: Lastly, the large intestine absorbs water and prepares waste for elimination.
Step 6: Thus, answer A includes all the structures involved in the entire digestive process, making it the correct choice.
Summary:
Choice B is incorrect as it omits the oral cavity. Choice C excludes the pharynx. Choice D is incorrect as it misses the oral cavity, pharynx, and esophagus.
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The exocrine pancreas secretes the following enzymes except:
- A. Chymotrypsinogen
- B. Prolestase
- C. Lactase
- D. Alph
Correct Answer: C
Rationale: The correct answer is C: Lactase. Lactase is an enzyme produced in the small intestine, not in the pancreas. The exocrine pancreas secretes digestive enzymes like chymotrypsinogen, proelastase, and lipase to aid in the digestion of proteins, fats, and carbohydrates. Lactase is responsible for breaking down lactose, a sugar found in dairy products, and is produced in the small intestine. Therefore, C is the correct answer. Choices A, B, and D are incorrect because chymotrypsinogen, proelastase, and alph are all enzymes produced by the pancreas to aid in digestion.
Which cells secrete hydrochloric acid in the stomach?
- A. Parietal cells
- B. Chief cells
- C. Mucous neck cells
- D. Enteroendocrine cells
Correct Answer: A
Rationale: The correct answer is A: Parietal cells. Parietal cells secrete hydrochloric acid in the stomach to create the acidic environment necessary for digestion. They also secrete intrinsic factor for vitamin B12 absorption. Chief cells produce pepsinogen, not hydrochloric acid. Mucous neck cells secrete mucus to protect the stomach lining. Enteroendocrine cells secrete hormones like gastrin, not hydrochloric acid. Therefore, the correct choice is A as it directly produces hydrochloric acid in the stomach.
What is the function of bile in digestion?
- A. Emulsify fats
- B. Break down proteins
- C. Break down carbohydrates
- D. None of the above
Correct Answer: A
Rationale: The correct answer is A: Emulsify fats. Bile emulsifies fats by breaking them down into smaller droplets, increasing the surface area for enzymes to work on, aiding in the digestion and absorption of fats. Choices B and C are incorrect as bile specifically targets fats, not proteins or carbohydrates. Choice D is incorrect as bile plays a crucial role in fat digestion.
Regarding deglutition (swallowing):
- A. Pharyngeal phase is voluntary.
- B. Is controlled by a center in the medulla oblongata.
- C. Readily occurs with an open mouth.
- D. Buccal phase is accompanied by apnea.
Correct Answer: B
Rationale: The correct answer is B because swallowing is controlled by the swallowing center in the medulla oblongata. This center coordinates the complex sequence of muscle contractions involved in swallowing, ensuring food moves from the mouth to the esophagus without entering the airway. The pharyngeal phase is actually involuntary, not voluntary (Choice A). Swallowing usually occurs with a closed mouth, not an open one (Choice C). Additionally, the buccal phase is not accompanied by apnea; breathing typically continues during this phase (Choice D). Therefore, the correct answer is B due to the central control of swallowing in the medulla oblongata.
Bacteria and other foreign material absorbed by the small intestine are destroyed by ______ cells found lining the hepatic sinusoids.
- A. Kupffer
- B. hepatic
- C. endothelial
- D. acinar
Correct Answer: A
Rationale: The correct answer is A: Kupffer cells. Kupffer cells are specialized macrophages found in the liver that play a crucial role in immune defense. They are responsible for destroying bacteria and foreign material absorbed by the small intestine as they pass through the hepatic sinusoids. Kupffer cells phagocytize these pathogens, preventing their entry into the bloodstream. The other choices, B: hepatic, C: endothelial, and D: acinar, do not have the specific function of destroying bacteria in the hepatic sinusoids. Hepatic cells are liver cells, endothelial cells line blood vessels, and acinar cells are found in exocrine glands.