Buerger waves (alpha waves) of EEG have the rhythm per sec of –
**Core Concept**
Buerger waves, also known as alpha waves, are slow-wave oscillations observed in the EEG during relaxed wakefulness with closed eyes. These waves are primarily associated with the idling state of the brain and are a key feature of normal brain activity in the absence of cognitive engagement.
**Why the Correct Answer is Right**
Alpha waves (13β30 Hz) are most prominent in the occipital lobes when a person is relaxed and eyes are closed. They are typically seen in the range of 10β16 Hz in adults, with the classic "alpha rhythm" falling between 13 and 30 Hz. This frequency range is distinct from other EEG waves like delta (0β4 Hz), theta (4β7 Hz), and beta (13β30 Hz), though beta overlaps with the upper end of alpha. The term "Buerger waves" refers to this alpha wave pattern, and their frequency is firmly established in neurophysiological literature.
**Why Each Wrong Option is Incorrect**
Option A: 0β4 Hz is the delta wave range, associated with deep sleep or unconsciousness, not alpha waves.
Option B: 7β4 Hz is not a valid range (4β7 Hz is theta), which occurs during drowsiness or light sleep, not relaxed wakefulness.
Option D: 13β30 Hz includes both alpha and beta waves, but the *classic* alpha wave range is specifically 10β13 Hz, not extending to 30 Hz. However, the broader range 13β30 Hz is accepted in many textbooks as the alpha wave band, especially when including beta activity. Still, option C is more precisely aligned with standard definitions.
**Clinical Pearl / High-Yield Fact**
Alpha waves disappear when a person opens their eyes or engages in mental activity. Their presence indicates a relaxed, alert state and is used clinically to assess brain function in EEG studies.
β Correct Answer: C. 13-Aug