Final answer:
There is no precise percentage of body fluid depletion at which the heart rate exceeds 100 bpm as it varies among individuals. However, significant body fluid loss can lead to an increased heart rate as a compensatory mechanism to maintain blood circulation.
Step-by-step explanation:
The question refers to the relationship between body fluid depletion and heart rate (HR). It asks at what percentage of body fluid depletion does the HR exceed 100 beats per minute (bpm). Although the question does not specify an exact percentage when this occurs, in the context of physiological responses to fluid loss, a significant fluid deficit can result in an elevated HR to compensate for decreased blood volume and maintain adequate circulation. This can happen during conditions like dehydration or extreme physical activity, such as a marathon, where blood flow can increase up to 10 times the resting rate, and fluid reserves are rapidly depleted.
Water constitutes 50-70% of the adult body weight, crucial for maintaining blood volume and pressure. For example, intracellular fluid represents about 50% of the body weight in lean individuals, and any substantial decline in total body water can stress the cardiovascular system, potentially causing the HR to rise above 100 bpm. The exact percentage at which HR exceeds 100 bpm due to dehydration cannot be precisely stated as it varies among individuals, but it's clear that losing a significant amount of body fluid can lead to a compensatory increase in heart rate.