Nokea
In the small intestine, movement of chyme is regulated primarily by
- A. secretin and cholecystokinin.
- B. the parasympathetic nervous system via the vagus nerve.
- C. local and mechanical stimulation.
- D. the enterogastric reflex caused by pressure of irritating substances in the colon.
Correct Answer: C
Rationale: The correct answer is C: local and mechanical stimulation. In the small intestine, movement of chyme is primarily regulated by local and mechanical stimulation, which triggers peristalsis and segmentation. This allows for the mixing and propulsion of chyme along the digestive tract.
A: Secretin and cholecystokinin are hormones involved in regulating pancreatic and gallbladder secretions, not movement of chyme in the small intestine.
B: The parasympathetic nervous system via the vagus nerve plays a role in stimulating digestive processes but is not the primary regulator of movement of chyme.
D: The enterogastric reflex is related to regulating stomach emptying in response to irritating substances, not movement of chyme in the small intestine.
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During a routine screening colonoscopy on a 56-year-old patient, a rectosigmoidal polyp was identified and remove The patient asks the nurse if his risk for colon cancer is increased because of the polyp. What is the best response by the nurse?
- A. It is very rare for polyps to become malignant but you should continue to have routine colonoscopies.'
- B. Individuals with polyps have a 100% lifetime risk of developing colorectal cancer and at an earlier age than those without polyps.'
- C. All polyps are abnormal and should be removed but the risk for cancer depends on the type and if malignant changes are present.'
- D. All polyps are premalignant and a source of most colon cancer. You will need to have a colonoscopy every 6 months to check for new polyps.'
Correct Answer: C
Rationale: Rationale:
1. Choice C is correct because it acknowledges that all polyps are abnormal and should be removed, but the risk for cancer depends on the type and presence of malignant changes.
2. This response is accurate as not all polyps become cancerous, and the risk varies depending on the specific characteristics of the polyp.
3. It also emphasizes the importance of removing polyps and monitoring for any signs of malignancy, aligning with best practice guidelines for colon cancer prevention.
4. In contrast, choices A, B, and D provide misleading information by either downplaying or exaggerating the risk associated with polyps, which can lead to unnecessary anxiety or complacency in the patient.
Which part of a tooth most closely resembles bone tissue?
- A. enamel
- B. cementum
- C. dentin
- D. gingiva
Correct Answer: C
Rationale: The correct answer is C: dentin. Dentin is the part of the tooth that closely resembles bone tissue because it is a hard, dense tissue similar to bone in composition and structure, providing support and protection to the tooth. Dentin is located beneath the enamel and cementum, forming the bulk of the tooth structure. Enamel (choice A) is the hardest tissue in the body but is not similar to bone tissue in composition. Cementum (choice B) is a hard tissue covering the roots of teeth but is not as similar to bone tissue as dentin. Gingiva (choice D) is the soft tissue that surrounds the teeth and is not similar to bone tissue.
A nurse is caring for a client who is receiving total parenteral nutrition (TPN). The nurse notices that the solution bag is almost empty and there is not another bag of TPN to administer. Which of the following IV solutions should the nurse administer until the next bag of TPN solution is available?
- A. 10% dextrose in water (D10W)
- B. 0.45% sodium chloride (0.45% NaCl)
- C. Lactated Ringer's solution
- D. 5% dextrose in lactated Ringer's solution (D5LR)
Correct Answer: A
Rationale: The correct answer is A: 10% dextrose in water (D10W). When a TPN bag is almost empty, abruptly stopping it can lead to hypoglycemia. Administering D10W provides a temporary source of glucose to prevent this. D10W is a hypertonic solution that delivers a high concentration of dextrose for energy. Option B (0.45% NaCl) is hypotonic and lacks the necessary glucose content. Option C (Lactated Ringer's solution) does not contain glucose, and option D (D5LR) contains lactate, which may not be suitable for all patients. Administering D10W is the most appropriate choice to prevent hypoglycemia until the next bag of TPN is available.
The pacemaker signal generated by the SA node spreads to the ventricles by passing through the AV node. What would happen to the contraction of the ventricles if there was a complete block at the AV node?
- A. the ventricles would cease beating
- B. the ventricles would beat very fast and uncontrollably
- C. the ventricles would contract rhythmically, but more slowly
- D. the ventricles would contract at the same rate as the atria
Correct Answer: C
Rationale: Rationale: A complete block at the AV node would prevent the transmission of the pacemaker signal from the SA node to the ventricles. As a result, the ventricles would not receive the signal to contract at their normal rate. Instead, they would rely on their inherent ability to generate impulses, resulting in a slower, but still rhythmic contraction. This scenario is known as an escape rhythm, where a lower pacemaker takes over in the absence of the SA node signal.
Summary:
A: the ventricles would cease beating - Incorrect, as the ventricles have their own intrinsic pacemaker.
B: the ventricles would beat very fast and uncontrollably - Incorrect, as a complete AV block would lead to a slower rhythm.
D: the ventricles would contract at the same rate as the atria - Incorrect, as the ventricles and atria have different intrinsic rates.
Surface area of the stomach is increased by
- A. gastric pits.
- B. plicae circulares.
- C. villi.
- D. microvilli.
Correct Answer: A
Rationale: The correct answer is A: gastric pits. Gastric pits are invaginations in the stomach lining that contain specialized cells for secretion of gastric juices. These pits increase the surface area of the stomach by providing a larger area for nutrient absorption and digestion. Plicae circulares are folds in the small intestine, not the stomach. Villi and microvilli are found in the small intestine and further increase surface area for absorption, not in the stomach.