Chapter 6 Forensic Toxicology

The Role of Forensic Toxicology What does a forensic toxicologist do? detect and identify drugs and poisons in body fluids, tissues, and organs What types of cases are investigated by forensic toxicologists? drug-related deaths Accidental poisonings Suicidal poisonings Homicidal poisonings

Toxicology of Alcohol knowing how the body metabolizes alcohol allows one to understand its effects and detect its presence Metabolism-the transformation of substances in the body in order to facilitate elimination from the body.

Metabolism of Alcohol 3 Basic Steps: Absorption-alcohol is absorbed into the blood stream from the walls of the stomach and small intestine Distribution- alcohol becomes distributed uniformly throughout the body’s fluids. Elimination- occurs by oxidation and excretion

Factors that Affect Absorption Alcohol content of beverage Amount consumed Rate of consumption Quantity and type of food in the stomach

Elimination Alcohol is eliminated from the body by: Oxidation- alcohol is converted to carbon dioxide and water; process starts in the liver; 95-98 % of alcohol is oxidized Excretion- The remaining alcohol is released in breath, urine, and perspiration

Blood Alcohol Concentration Amount of alcohol exhaled is directly proportional to the amount of alcohol in the blood Blood alcohol concentration is directly proportional to the alcohol content in the brain

Circulation Definitions Artery—a blood vessel that carries blood away from the heart Vein—a blood vessel that transports blood toward the heart Capillary—a tiny blood vessel—walls exchange materials between blood and tissues Alveoli—small sacs in lungs—exchange vapors between breath and blood

Circulation

Circulation