In which organ is carbonic anhydrase crucial for maintaining acid-base balance?

Correct Answer: B

Rationale: Carbonic anhydrase is crucial for acid-base balance by catalyzing the interconversion of carbon dioxide and bicarbonate ions in the blood. The kidneys regulate blood pH by reabsorbing bicarbonate and excreting hydrogen ions. Therefore, carbonic anhydrase in the kidneys plays a vital role in maintaining acid-base balance. The liver is not directly involved in this process but helps in detoxification and metabolism. The heart and pancreas do not have a primary role in acid-base balance regulation. Thus, the correct answer is B: Kidneys.

Correct Answer: D

Rationale: The correct answer is D because elastic fibers are more abundant in the bronchi and bronchioles than the upper respiratory tract. Elastic fibers provide elasticity and recoil to help with airway expansion and contraction during breathing. This is crucial in the bronchi and bronchioles to maintain airflow dynamics. Choice A is incorrect because regular bronchioles do not contain glands; they are found in the respiratory bronchioles. Choice B is incorrect because larynx contains a significant amount of cartilage, not smooth muscle. Choice C is incorrect because goblet cells are abundant in the larger bronchi, trachea, and bronchioles, not in the small bronchi and respiratory bronchioles.

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.

Correct Answer: B

Rationale: The correct answer is B: Arterial Blood. The lowercase "a" in ABG values denotes arterial blood, indicating that the values are specific to the blood obtained from an artery. ABG analysis provides information about the oxygen and carbon dioxide levels in the blood, as well as the pH and bicarbonate levels, which are crucial in assessing respiratory and metabolic functions. Choice A: Acid-base balance - This is incorrect because the lowercase "a" in ABG does not represent acid-base balance. Acid-base balance is determined by the pH level in the blood, which is one of the parameters measured in ABG analysis. Choice C: Arterial oxygen saturation - This is incorrect because oxygen saturation is typically measured using pulse oximetry, not through ABG analysis. ABG values focus on the partial pressure of oxygen in the arterial blood. Choice D: Alveoli - This is incorrect because ABG values do not directly represent the condition of the alveoli. ABG analysis

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.