The nurse is caring for a patient admitted with an acute exacerbation of chronic obstructive pulmonary disease. During assessment, the nurse finds that the patient is experiencing increased dyspnea. What is the most accurate measurement of the concentration of oxygen in the patient's blood?

Correct Answer: C

Rationale: The correct answer is C: An arterial blood gas (ABG) study. This is the most accurate measurement of the concentration of oxygen in the patient's blood because ABG provides direct measurement of oxygen levels, including partial pressure of oxygen (PaO2). It also gives information on other important parameters like pH and carbon dioxide levels. Arterial blood is the best representation of oxygenation status. Choice A (A capillary blood sample) may provide some information on oxygen saturation but is not as accurate as an ABG for measuring oxygen levels in the blood. Choice B (Pulse oximetry) measures oxygen saturation in peripheral blood and can give a quick estimate of oxygen levels, but it is not as accurate as an ABG for determining the actual oxygen concentration in the blood. Choice D (A complete blood count) does not provide direct information on oxygen levels in the blood, as it mainly focuses on the cellular components of blood such as red blood cells, white blood cells, and

Correct Answer: A

Rationale: The 'Adams' Apple' is the prominent bulge in the front of the neck and corresponds to the thyroid cartilage. This cartilage forms the largest part of the larynx and is more prominent in males due to hormonal differences. The cricoid cartilage (Choice B) is located below the thyroid cartilage. Corniculate cartilage (Choice C) and cuneiform cartilage (Choice D) are smaller cartilages in the larynx and are not responsible for the 'Adams' Apple' prominence.

Correct Answer: A

Rationale: The correct answer is A: venous blood. In the body, carbon dioxide is carried in the blood, primarily in the form of bicarbonate ions. Venous blood, returning from tissues to the heart, has higher levels of carbon dioxide compared to arterial blood. This results in a higher partial pressure of carbon dioxide in venous blood. Alveolar air (B) has a lower partial pressure of carbon dioxide due to gas exchange in the lungs, while expired air (C) has even lower levels as carbon dioxide is exhaled. Inspired air (D) has the lowest partial pressure of carbon dioxide as it has not yet entered the body.

Correct Answer: B

Rationale: A 10% increase in CO2 levels triggers chemoreceptors to signal the brainstem, increasing the respiratory rate to eliminate excess CO2. This is known as hypercapnia-induced hyperventilation. Option A is incorrect because an increase in CO2 levels would not decrease the rate of breathing. Option C is incorrect because an increase in CO2 would actually stimulate an increase in pulmonary ventilation to remove the excess CO2. Option D is incorrect because alveolar ventilation (gas exchange in the lungs) would increase, not decrease, to maintain proper oxygen and CO2 levels in the body.

Correct Answer: B

Rationale: The correct answer is B: smooth muscle. Smooth muscle is the type of muscle that wraps around a respiratory bronchiole and can contract or relax to change the diameter of the airway. This allows for regulation of airflow in the respiratory system. Skeletal muscle (choice A) is attached to bones and is under voluntary control, not found in the bronchioles. Cardiac muscle (choice C) is specific to the heart and does not control airway diameter. Voluntary muscle (choice D) refers to skeletal muscle, which is not present in the bronchioles and does not regulate airway diameter involuntarily.