What percentage of the circumference of the head is T5 from T3?

The correct answer is based on an understanding of electrode placement in electroencephalogram (EEG) monitoring and the associated percentages of head circumference used in the 10-20 system of electrode placement. In this system, T3 and T5 are referenced points on the head where T3 is located on the left side and T5 is positioned further back, more towards the occipital area.

The measurement from T3 to T5 is calculated based on the head's circumference, which is divided into specific percentages for accurate placement of electrodes. The distance from T3 to T5 represents approximately 10% of the total head circumference. This is a standardized method that helps ensure consistency in electrode positioning across various patients and studies, which is crucial for obtaining reliable EEG data.

Understanding these measurements assists sleep technicians in properly placing electrodes for sleep studies, ensuring quality data collection, and ultimately aiding in accurate diagnoses.