Advanced Dental Admission Test (ADAT)

What is one key feature of flattened pyknotic cells in the stratum corneum?

1. They are loosely packed

2. They are composed of tightly packed tonofilaments

3. They aid in nutrient absorption

4. They are rich in blood supply

The correct answer is: They are composed of tightly packed tonofilaments

The correct answer highlights that flattened pyknotic cells in the stratum corneum are composed of tightly packed tonofilaments. This characteristic is significant because tonofilaments provide structural support and strength to the cells, which are in the outermost layer of the skin. This tightly packed arrangement contributes to the protective barrier function of the skin, helping to prevent water loss and protect against environmental damage. In the context of the other options, the packed structure of tonofilaments clearly sets these cells apart from the notion of being loosely packed, which would not provide the same level of protection. The stratum corneum does not facilitate nutrient absorption, as it primarily serves a protective function rather than participating in metabolic activities. Additionally, the stratum corneum is avascular, meaning it lacks a direct blood supply; thus, the presence of flattened pyknotic cells would not correlate with being rich in blood supply.