Certified in Public Health (CPH) Practice Exam

Within the body, lipophilic substances:

1. Are poorly absorbed in the digestive tract

2. Are excreted rapidly in the urine

3. Accumulate in bones and teeth

4. Accumulate in body fat

The correct answer is: Accumulate in body fat

Lipophilic substances, also known as fat-soluble substances, possess a natural tendency to dissolve in fats and lipids. This characteristic enables them to accumulate in body fat rather than being rapidly excreted or poorly absorbed. When lipophilic substances are ingested, they are often absorbed more efficiently in the digestive tract, since they can easily pass through cell membranes that are composed of lipid layers. As these substances enter the bloodstream, they are transported and can be stored in adipose tissue (body fat). This accumulation is significant as it can affect how these substances are metabolized and the duration they remain in the body, potentially impacting overall health. In contrast, the other options reflect mechanisms inconsistent with the behavior of lipophilic substances. For instance, lipophilic substances are not typically poorly absorbed in the digestive tract; they tend to be well absorbed. They are also not rapidly excreted in urine, as water-soluble substances are. Lastly, while certain substances can accumulate in bones and teeth, this is not a characteristic feature of lipophilic substances as a general principle. Instead, they primarily have a predilection for storage in body fat, which is why the correct answer highlights this aspect.