A client who is human immunodeficiency virus-positive has had a Mantoux skin test. The nurse notes a 7-mm area of induration at the site of the skin test. The nurse interprets the results as:

Correct Answer: A

Rationale: The correct answer is A: Positive. In individuals with HIV, a positive Mantoux test is considered when the induration is 5 mm or greater. A 7-mm area of induration indicates a positive result, suggesting an immune response to the tuberculin antigen, potentially due to latent tuberculosis infection. The other choices are incorrect because a 7-mm induration in an HIV-positive client is not considered negative, inconclusive, or indicative of the need for repeat testing based on current guidelines.

Correct Answer: B

Rationale: The correct answer is B: nasal cavities. The term "septum" refers to a partition or dividing wall that separates two cavities. In the context of the respiratory system, the nasal septum divides the nasal cavities into left and right sides. This separation helps to regulate airflow and also provides structural support for the nasal passages. Other choices are incorrect because: A: The larynx is not typically associated with a septum. It is primarily responsible for vocalization and protecting the airway. C: The pharynx is a passageway for air and food, but it does not contain a septum dividing it into distinct sections. D: The glottis is the space between the vocal cords in the larynx and does not have a septum separating it into parts.

Correct Answer: A

Rationale: The correct answer is A: carbon dioxide concentrations are high. When carbon dioxide levels are high, it leads to a decrease in blood pH, triggering hemoglobin to release oxygen more readily through the Bohr effect. This is a physiological response to maintain homeostasis. The other choices (B, C, D) do not directly affect the release of oxygen from hemoglobin.

Correct Answer: C

Rationale: The correct answer is C: diffusion. During internal and external respiration, gases move from areas of high concentration to low concentration through passive diffusion. This process is driven by the concentration gradient, allowing gases like oxygen and carbon dioxide to exchange in the lungs and tissues. Osmosis (A) is the movement of water across a semipermeable membrane, not gases. Active transport (B) requires energy and moves substances against their concentration gradient, which is not how gases move during respiration. Endocytosis (D) is a process where cells engulf substances by forming vesicles, not how gases are exchanged in respiration.

Correct Answer: A

Rationale: The vital capacity of lungs is the maximum amount of air a person can exhale after a maximum inhalation. The average vital capacity for an adult human is typically between 3000-4500 ml. This range allows for efficient gas exchange in the lungs. Choice B (1500-1800 ml) and Choice C (2000-2500 ml) fall below the average vital capacity, indicating limited lung capacity. Choice D (500-1000 ml) is significantly low and would not support normal respiratory function. Therefore, Choice A (3000-4500 ml) is the correct answer as it aligns with the average vital capacity range for an average human.