What physiological signs are commonly associated with night terrors?

Night terrors, often occurring during deep sleep, are characterized by a variety of physiological signs primarily due to the activation of the body's fight-or-flight response. The correct answer reflects commonly observed physiological reactions such as tachycardia, which is an increased heart rate, and sweating, both of which occur as the body reacts to perceived danger or fear during the episode.

During a night terror, an individual may appear to be awake but is actually in a state of deep non-REM sleep, often exhibiting distress without full awareness. The physiological responses, including tachycardia and sweating, can lead to a significant mismatch between the physical state and the apparent behavior, as the person may scream or thrash about, creating a scene of panic.

In contrast, stillness and quietness, drowsiness and calmness, or unresponsiveness and confusion do not capture the typical physiological activity associated with night terrors. While confusion may follow the episode as the individual regains full awareness, it is not a primary physiological sign associated with the actual occurrence of the night terror itself. The hallmark signs of night terrors are characterized more by the intense physical reactions that signify the arousal of the autonomic nervous system.