What symptoms may occur due to a moderate increase in CO2 concentration in inspired air?

• A. Hyperventilation
• B. Hypoxia and cyanosis
• C. Dyspnea and headache
• D. Increased urination

Answer: (C)

A moderate increase in carbon dioxide (CO2) concentration in inspired air leads to several physiological responses, particularly affecting the respiratory and central nervous systems. Elevated CO2 levels can cause symptoms such as dyspnea, which is the sensation of breathlessness or difficulty in breathing. This occurs because the body senses increased CO2 (hypercapnia) and attempts to compensate by signaling for deeper and more frequent breaths.

Headache is another common symptom associated with rising CO2 levels. Increased CO2 leads to respiratory acidosis, resulting in vasodilation of cerebral blood vessels. This increased blood flow to the brain can often trigger headaches in individuals experiencing excessive CO2 concentration.

Understanding the relationship between CO2 levels and respiratory symptoms provides crucial insights into the effects of respiratory distress. For example, in scenarios where CO2 levels are abnormally high, individuals may also experience confusion or impaired cognitive function due to the sedative effects of hypercapnia on the brain.

In ventilatory issues or conditions that lead to respiratory insufficiency, awareness of these symptoms is vital, as they indicate the body's maladaptive responses to what may be an unsafe environment due to rising CO2. Thus, focusing on the correct symptoms—dyspnea and headache—helps in recognizing the body’s