Nokea
Which of the following lymphocytes are involved in innate immunity?
- A. natural killer (NK) cells
- B. plasma cells
- C. CD8 T cells
- D. B memory cells
Correct Answer: A
Rationale: Natural killer (NK) cells are involved in innate immunity as they are able to directly kill virus-infected cells and tumor cells without prior sensitization. They are part of the body's first line of defense against infections. Plasma cells, CD8 T cells, and B memory cells are all part of adaptive immunity, which involves a specific response to pathogens and requires prior exposure. Therefore, they are not involved in innate immunity.
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O2 dissociation curve shift to R) by all of the following except
- A. Increase [H+]
- B. pCO2
- C. Increase temperature
- D. Carbon monoxide
Correct Answer: D
Rationale: The correct answer is D: Carbon monoxide. Carbon monoxide does not shift the O2 dissociation curve to the right (R) because it binds to hemoglobin with a higher affinity than oxygen, causing a leftward shift (L). Increased [H+], pCO2, and temperature all shift the curve to the right by decreasing hemoglobin's affinity for oxygen.
The covering of the lung is called
- A. Pericardium
- B. Perichondrium
- C. Pleural membrane/ pleura
- D. Peritoneum
Correct Answer: C
Rationale: The correct answer is C: Pleural membrane/pleura. The pleural membrane is a double-layered serous membrane that covers the lungs. The visceral pleura is attached to the lung surface, while the parietal pleura lines the chest cavity. This arrangement helps reduce friction and allows the lungs to expand during breathing.
A: Pericardium covers the heart, not the lungs.
B: Perichondrium covers cartilage, not the lungs.
D: Peritoneum covers abdominal organs, not the lungs.
Therefore, the correct choice is C because it specifically refers to the covering of the lungs.
A female adult client has a tracheostomy but doesn't require continuous mechanical ventilation. When weaning the client from the tracheostomy tube, the nurse initially should plug the opening in the tube for:
- A. 15 to 60 seconds.
- B. 5 to 20 minutes.
- C. 30 to 40 minutes.
- D. 45 to 60 minutes.
Correct Answer: B
Rationale: The correct answer is B: 5 to 20 minutes. Plugging the tracheostomy tube for this duration allows the client to gradually adapt to breathing without the assistance of the tube. Initially, the client may experience increased respiratory effort, which helps improve lung function. Plugging the tube for too short a time (A) may not provide enough challenge for the client, while plugging it for too long (C, D) may cause distress or potential complications due to lack of oxygen. Therefore, the optimal time frame of 5 to 20 minutes ensures a safe and effective weaning process for the client.
The nurse assesses wheezes in a patient with asthma and realizes that these breath sounds result from:
- A. Increased thickness of respiratory secretions.
- B. Use of accessory muscles of respiration.
- C. Tachypnea and tachycardia.
- D. Movement of air through narrowed airways.
Correct Answer: D
Rationale: The correct answer is D because wheezes in asthma are caused by the movement of air through narrowed airways due to bronchoconstriction and inflammation. This narrowing leads to turbulent airflow, resulting in the characteristic high-pitched musical sound of wheezes. Increased thickness of respiratory secretions (A) may cause crackles, not wheezes. Use of accessory muscles (B) indicates respiratory distress but does not directly cause wheezes. Tachypnea and tachycardia (C) are common in asthma but do not directly cause wheezes. Thus, D is the most directly related to the pathophysiology of wheezes in asthma.
What is the most effective treatment for cystic fibrosis?
- A. Heart-lung transplant
- B. Administration of prophylactic antibiotics
- C. Administration of nebulized bronchodilators
- D. Vigorous and consistent chest physiotherapy
Correct Answer: D
Rationale: The most effective treatment for cystic fibrosis is vigorous and consistent chest physiotherapy, as it helps in clearing the mucus and improving lung function.