Alcohol Influence and Physiological Effects Flashcards

Under federal regulations, the per se BAC limit for operators of commercial motor vehicles (CMV) is:

Answer: 0.04%

Federal law (49 CFR Part 382) sets the BAC limit for CMV operators at 0.04%, half the standard adult limit, due to the increased public safety risk posed by large commercial vehicles.

Under most U.S. zero-tolerance laws, drivers under the age of 21 may be charged with DUI at a BAC of:

Answer: 0.02% or higher

Most states have adopted zero-tolerance laws setting the BAC limit for drivers under 21 at 0.02% (effectively zero), reflecting that any alcohol consumption by minors is illegal.

The forensic technique of 'retrograde extrapolation' refers to:

Answer: Calculating what a person's BAC was at an earlier time based on a later chemical test result

Retrograde extrapolation uses elimination rate formulas to work backward from a known BAC (measured at testing) to estimate what BAC was at the time of driving.

Carbonated mixers (such as tonic water or cola) typically have what effect on alcohol absorption?

Answer: They speed up alcohol absorption into the bloodstream

Carbonation increases gastric pressure and speeds gastric emptying, causing alcohol to enter the small intestine faster and resulting in more rapid absorption.

Alcohol is distributed throughout the body primarily via body water because:

Answer: Alcohol is water-soluble and distributes through total body water

Alcohol is highly water-soluble and distributes evenly throughout the body's total water content, which is why body composition (water vs. fat percentage) affects BAC.

In DUI investigations, the Widmark formula is used to:

Answer: Estimate a subject's BAC based on the amount of alcohol consumed, body weight, and elapsed time

The Widmark formula estimates theoretical BAC by factoring in the amount of alcohol consumed, the individual's body weight and gender factor (r), and time elapsed since drinking began.

Women typically achieve higher BAC levels than men after consuming the same amount of alcohol primarily because women:

Answer: Generally have a higher percentage of body fat and a lower percentage of total body water

Women typically have a higher body fat percentage and lower body water percentage than men of the same weight, so the same amount of alcohol is distributed in a smaller volume of water, resulting in a higher BAC.