Nokea
The primary chemical stimulus for breathing is the concentration of
- A. carbon monoxide in the blood
- B. carbon dioxide in the blood
- C. oxygen in the blood
- D. carbonic acid in the blood
Correct Answer: B
Rationale: The correct answer is B: carbon dioxide in the blood. In the body, carbon dioxide levels are monitored by chemoreceptors in the brainstem. When carbon dioxide levels rise, it triggers an increase in breathing rate to expel excess carbon dioxide and restore the balance of gases in the blood. This process is known as the respiratory drive. Carbon monoxide (A) is a toxic gas that interferes with oxygen transport but does not directly affect breathing stimulus. Oxygen (C) levels in the blood are important for maintaining tissue oxygenation but do not directly regulate breathing. Carbonic acid (D) is a product of carbon dioxide and water, and its levels do not directly stimulate breathing.
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The nurse is caring for a client who is one hour post cardiac catheterization. What task should the nurse delegate to a licensed practical/vocational nurse (LPN/VN)?
- A. Teach the patient about the post procedure plan of care.
- B. Perform the initial assessment of the catheter insertion site.
- C. Give the scheduled lipid-lowering medication.
- D. Titrate the diltiazem infusion according to the agency protocol.
Correct Answer: C
Rationale: The correct answer is C: Give the scheduled lipid-lowering medication. LPN/VNs can administer medications, including lipid-lowering drugs, under the supervision of a registered nurse. Teaching (choice A) requires a higher level of critical thinking and education, which is typically done by an RN. Performing an initial assessment (choice B) requires advanced assessment skills that an LPN/VN may not have. Titration of medications (choice D) involves adjusting dosages based on specific parameters, which is beyond the scope of practice for an LPN/VN.
The nurse is caring for a patient with a lower respiratory tract infection. When planning a focused respiratory assessment, the nurse should know that this type of infection most often causes what?
- A. Impaired gas exchange
- B. Collapsed bronchial structures
- C. Necrosis of the alveoli
- D. Closed bronchial tree
Correct Answer: A
Rationale: Step 1: Lower respiratory tract infection affects the lungs where gas exchange occurs.
Step 2: Infections can lead to inflammation and fluid buildup in the lungs.
Step 3: This impairs the exchange of oxygen and carbon dioxide.
Step 4: Impaired gas exchange can lead to hypoxemia and respiratory distress.
Step 5: Therefore, the correct answer is A: Impaired gas exchange. Other choices are incorrect because they do not directly relate to the physiological consequences of a lower respiratory tract infection.
Diaphragm present in mammals is
- A. Membrane between external and middle ear
- B. Membrane around the brain
- C. Partition between the thoracic and abdominal cavities
- D. Membrane around lungs
Correct Answer: C
Rationale: The diaphragm in mammals is a muscular structure that separates the thoracic and abdominal cavities. This is essential for breathing as it contracts and relaxes to facilitate the movement of air into and out of the lungs. Therefore, the correct answer is C.
Choice A is incorrect because the membrane between the external and middle ear is called the eardrum or tympanic membrane. Choice B is incorrect as the membrane around the brain is the meninges. Choice D is incorrect as the membrane around the lungs is the pleura.
Residual volume in lungs of an average human is
- A. 500 ml
- B. 3-4.5 ml
- C. 1000 ml
- D. 1500 ml
Correct Answer: D
Rationale: The correct answer is D (1500 ml) because residual volume refers to the amount of air left in the lungs after maximal exhalation, which is around 1200-1500 ml in an average human. This volume is necessary to keep the alveoli inflated and prevent lung collapse. Choices A (500 ml), B (3-4.5 ml), and C (1000 ml) are incorrect because they do not accurately represent the typical residual volume in the lungs of an average human. Choice A is too low, choices B and C are significantly below the actual range of residual volume.
Hemoglobin
- A. tends to release oxygen under warmer temperatures
- B. picks up more oxygen the higher its partial pressure.
- C. picks up more oxygen when it is saturated
- D. will give up oxygen when the partial pressure of oxygen is higher than it is in the lungs.
Correct Answer: B
Rationale: The correct answer is B because hemoglobin follows the principle of partial pressure, which states that gases move from areas of higher partial pressure to lower partial pressure. Therefore, hemoglobin will pick up more oxygen when the partial pressure of oxygen is higher, such as in the lungs. Choice A is incorrect because hemoglobin actually releases oxygen at higher temperatures. Choice C is incorrect because hemoglobin picks up oxygen when it is not fully saturated. Choice D is incorrect because hemoglobin releases oxygen when the partial pressure of oxygen is higher, not when it is lower.