Nokea
Regarding control of ventilation
- A. The apneustic centre lies in the medulla
- B. The central chemoreceptors respond to changes in oxygen concentrations
- C. The chemoreceptors in the aortic bodies respond to a fall in arterial pH
- D. Peripheral chemoreceptors respond to decreases in arterial pO2
Correct Answer: D
Rationale: The correct answer is D: Peripheral chemoreceptors respond to decreases in arterial pO2. These chemoreceptors located in the carotid bodies and aortic bodies detect changes in arterial pO2 levels, triggering an increase in ventilation to compensate for low oxygen levels. The apneustic center (A) is located in the pons, not the medulla. Central chemoreceptors (B) primarily respond to changes in arterial CO2 levels, not oxygen concentrations. The chemoreceptors in the aortic bodies (C) primarily respond to changes in arterial pCO2, not pH. Overall, choice D is correct due to the specific role of peripheral chemoreceptors in detecting decreases in arterial pO2 levels and regulating ventilation accordingly.
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A nurse is suctioning fluids from a male client via a tracheostomy tube. When suctioning, the nurse must limit the suctioning time to a maximum of:
- A. 1 minute
- B. 5 seconds
- C. 10 seconds
- D. 30 second
Correct Answer: C
Rationale: The correct answer is C: 10 seconds. Suctioning time for a tracheostomy tube should be limited to 10 seconds to prevent hypoxia and tissue damage. Prolonged suctioning can lead to decreased oxygenation and potential trauma to the airway. Choice A (1 minute) is too long and can cause harm. Choice B (5 seconds) is too short to effectively clear secretions. Choice D (30 seconds) exceeds the recommended time limit and can lead to complications. Therefore, limiting suctioning time to 10 seconds is the safest and most effective approach.
The atmospheric pressure at sea level is
- A. 1,000mm Hg.
- B. 760mm Hg.
- C. 540mm Hg.
- D. 400mm Hg.
Correct Answer: B
Rationale: The atmospheric pressure at sea level is typically around 760mm Hg, which is equivalent to 101.3 kilopascals. This is the standard atmospheric pressure used in various scientific calculations. This value represents the pressure exerted by the weight of air above a given area at sea level. Choice B is correct because it accurately reflects the standard atmospheric pressure at sea level. Choices A, C, and D are incorrect as they do not match the accepted value for atmospheric pressure at sea level.
Which of the following signs may be revealed in a client with tonsillar infection by a visual examination if group A streptococci is the cause?
- A. White patches on the tonsils
- B. Hemorrhage in the tonsils
- C. Hypertrophied tonsils
- D. Bleeding in the tonsils
Correct Answer: A
Rationale: The correct answer is A. White patches on the tonsils are characteristic of streptococcal infections, such as strep throat. B (hemorrhage) and D (bleeding) are not typical findings in streptococcal infections. C (hypertrophied tonsils) may occur but is not specific to group A streptococci.
A patient who has successfully been treated for a pulmonary embolism is about to be discharged. How can he lower the risk of experiencing another pulmonary embolism?
- A. Avoid sitting and standing for too long and do not cross legs.
- B. Take vitamin K with heparin.
- C. Avoid confined spaces.
- D. Jog 5 miles each day.
Correct Answer: A
Rationale: The correct answer is A. Avoiding prolonged immobility and crossing legs reduces the risk of venous thrombosis. B is incorrect because vitamin K antagonizes heparin. C (avoiding confined spaces) is unrelated. D (jogging) is beneficial but not directly preventive.
The patient has just had an MRI ordered because a routine chest x-ray showed suspicious areas in the right lung. The physician suspects bronchogenic carcinoma. An MRI would most likely be ordered to assess for what in this patient?
- A. Alveolar dysfunction
- B. Forced vital capacity
- C. Tidal volume
- D. Chest wall invasion
Correct Answer: D
Rationale: The correct answer is D: Chest wall invasion. An MRI would be ordered to assess for any potential invasion of the chest wall by the suspected bronchogenic carcinoma. MRI provides detailed imaging of soft tissues and can help determine the extent of tumor invasion beyond the lungs.
Explanation:
A: Alveolar dysfunction - Alveolar dysfunction is typically assessed using pulmonary function tests or imaging techniques like CT scans, not MRI.
B: Forced vital capacity - Forced vital capacity is a measure of lung function and is not typically assessed using MRI.
C: Tidal volume - Tidal volume is a measure of the volume of air moved in and out of the lungs during normal breathing and is not assessed using MRI in this context.