What is the normal range for partial pressure of carbon dioxide (PCO2) in arterial blood?

The normal range for the partial pressure of carbon dioxide (PCO2) in arterial blood is indeed between 35-45 mm Hg. This range is important because it reflects the balance of carbon dioxide in the blood and is crucial for maintaining proper acid-base homeostasis. PCO2 levels are influenced by respiratory function; they increase when ventilation is inadequate, leading to respiratory acidosis, and decrease with hyperventilation, resulting in respiratory alkalosis. Thus, maintaining PCO2 within this range is vital for optimal physiological functioning.

The other options provided either fall below or above the established normal physiological limits. Values outside the normal range can indicate various pathophysiological conditions, hence an understanding of the correct range aids clinical assessments concerning respiratory and metabolic health.