Certified Transport Registered Nurse Certification Practice Exam

At elevations of 20,000 - 30,000 ft, what physiological effects can humans experience?

1. Severe dehydration

2. Confusion and seizures

3. Hyperactivity

4. Drowsiness

The correct answer is: Confusion and seizures

At elevations of 20,000 to 30,000 feet, humans experience significant changes in atmospheric pressure and oxygen availability. These conditions can lead to hypoxia, a state in which the body or a region of the body is deprived of adequate oxygen supply. As the altitude increases, the partial pressure of oxygen decreases, which can cause adverse effects on cognitive function and overall mental status. This can manifest as confusion, disorientation, and in severe cases, seizures. The brain is particularly sensitive to changes in oxygen availability, which explains why cognitive symptoms are prominent at high altitudes. Other options, while they might seem plausible, do not directly correlate as common physiological responses at such high elevations. For instance, severe dehydration typically isn't a direct result of altitude alone but rather associated with environmental conditions and fluid intake. Similarly, hyperactivity is not typical at high altitudes, as the body is under stress, which usually leads to fatigue rather than increased activity. Drowsiness can occur, but it is more often linked to fatigue from the exertion of compensating for lower oxygen rather than a primary effect like confusion or seizures, which are more directly related to hypoxia. Thus, confusion and seizures are clear indicators of the severe impact that high