Nokea
In human, the cardiac sphincter surrounds the cardiac orifice in the digestive tract. The failure of this sphincter's normal function will result in
- A. regurgation of the food into the oesophagus
- B. loss of control of defecation
- C. movement of the bolus into the trachea rather than the oesophagus
- D. rapid emptying from the stomach to the small intestine
Correct Answer: A
Rationale: The correct answer is A: regurgitation of the food into the oesophagus. The cardiac sphincter is located at the junction between the esophagus and the stomach. Its main function is to prevent the backflow of stomach contents into the esophagus. If the cardiac sphincter fails to function properly, it can lead to regurgitation, where stomach contents flow back into the esophagus, causing discomfort and potential damage to the esophageal lining.
Summary:
B: Loss of control of defecation is not related to the cardiac sphincter, as it primarily functions in the upper digestive tract.
C: Movement of the bolus into the trachea is related to swallowing reflex and epiglottis function, not the cardiac sphincter.
D: Rapid emptying from the stomach to the small intestine is controlled by the pyloric sphincter, not the cardiac sphincter.
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The nurse is educating a patient who is starting treatment with warfarin. Which instruction is most important to include in the teaching plan?
- A. "You can continue taking your aspirin as prescribed."
- B. "Be sure to have regular blood tests to monitor your INR."
- C. "You should increase your intake of vitamin K-rich foods."
- D. "If you miss a dose, double the dose the next day."
Correct Answer: B
Rationale: The correct answer is B: "Be sure to have regular blood tests to monitor your INR." Warfarin is a medication that requires close monitoring of the International Normalized Ratio (INR) to ensure it is within the therapeutic range. Regular blood tests are crucial to prevent complications such as bleeding or blood clots.
Choice A is incorrect because aspirin increases the risk of bleeding when taken with warfarin. Choice C is incorrect because increasing vitamin K-rich foods can interfere with the effectiveness of warfarin. Choice D is incorrect because doubling the dose can lead to an increased risk of bleeding. Regular monitoring of INR levels is essential for safe and effective warfarin therapy.
Chemical digestion of starch foods begins in the:
- A. mouth
- B. stomach
- C. small intestine
- D. large intestine
Correct Answer: A
Rationale: The correct answer is A: mouth. Salivary amylase, an enzyme in saliva, initiates the breakdown of starch into maltose in the mouth. This process marks the beginning of chemical digestion of starch foods. In contrast, the stomach primarily digests proteins, the small intestine further breaks down carbohydrates, proteins, and fats, while the large intestine absorbs water and minerals. Therefore, options B, C, and D are incorrect as they do not represent the initial site of starch digestion.
These contractions occur 3 to 4 times a day and involve large parts of the transverse and descending colon. These contractions are called
- A. mass movements.
- B. haustral churning.
- C. the defecation reflex.
- D. teniae coli waves.
Correct Answer: A
Rationale: The correct answer is A: mass movements. Mass movements are strong contractions that occur 3 to 4 times a day, moving large amounts of fecal material through the colon. This process involves the transverse and descending colon, which aligns with the description provided in the question. Mass movements help propel waste towards the rectum for elimination.
Choice B, haustral churning, refers to the mixing and propelling actions that occur in the haustra of the colon, not involving large parts of the transverse and descending colon. Choice C, the defecation reflex, is the process that triggers the urge to defecate, not specific contractions involving the colon. Choice D, teniae coli waves, are contractions of the longitudinal muscles of the colon that create the haustra, not the strong propulsive contractions described in the question.
Which single statement about fat digestion and absorption is correct?
- A. Absorption of fatty acids in the intestine occurs mainly through FABP and FAT/CD36 transport proteins in the enterocytes of the distal duodenum
- B. After absorption, medium chain triglycerides (MCT) enter the lymphatic system, whereas long chain triglycerides enter the portal blood system.
- C. The products of partial digestion of triglycerides (triacylglycerols) can form mixed micelles with pancreatic cholesterol and phospholipids and this increases absorption
- D. Triglycerides (triacylglycerols) must be emulsified and digested before the fatty acids can be transported
Correct Answer: D
Rationale: Rationale for Correct Answer D (Triglycerides must be emulsified and digested before fatty acids can be transported):
1. Triglycerides are large molecules that cannot be directly absorbed by the intestinal cells.
2. Emulsification breaks down triglycerides into smaller droplets, increasing the surface area for enzyme action.
3. Enzymatic digestion of triglycerides by lipases results in the release of fatty acids and monoglycerides.
4. These breakdown products are then absorbed by enterocytes in the small intestine.
Summary of Why Other Choices are Incorrect:
A: FABP and FAT/CD36 proteins are involved in fatty acid transport, not triglyceride digestion.
B: Both medium and long-chain triglycerides are absorbed into the lymphatic system via chylomicrons.
C: While mixed micelles aid in lipid absorption, they are not essential for the initial digestion of triglycerides.
Where does chemical digestion of carbohydrates begin?
- A. Mouth
- B. Stomach
- C. Small intestine
- D. Large intestine
Correct Answer: A
Rationale: The correct answer is A: Mouth. In the mouth, salivary amylase is secreted, which starts breaking down carbohydrates into simpler sugars like maltose. This initial breakdown of carbohydrates through the enzyme amylase marks the beginning of chemical digestion. The stomach primarily digests proteins, not carbohydrates (eliminating option B). The small intestine is where most of the carbohydrate digestion and absorption occurs, but the process begins in the mouth (eliminating option C). The large intestine is responsible for absorbing water and electrolytes, not carbohydrate digestion (eliminating option D).