The stratum basale’s proximity to the dermis means that:
The stratum basale has easy access to the bloodstream
The stratum basale is the most likely layer to experience shearing forces
The stratum basale is the most likely to get infected
The stratum basale is the least likely layer to make waterproofing keratin
The correct answer and explanation is :
Correct Answer:
The stratum basale has easy access to the bloodstream.
Explanation:
The stratum basale (also called the basal layer) is the deepest layer of the epidermis, sitting directly above the dermis. This layer consists of a single row of basal cells, which include keratinocytes (precursors of skin cells), melanocytes (responsible for pigment production), and Merkel cells (involved in sensation).
Proximity to the Dermis and Blood Supply
Unlike the upper layers of the epidermis, which are made of dead or dying keratinized cells, the stratum basale is alive and actively dividing. However, since the epidermis itself is avascular (lacks blood vessels), the cells in the stratum basale rely on diffusion of oxygen and nutrients from the underlying dermis, where capillaries provide a rich blood supply.
Why the Other Options Are Incorrect
- “The stratum basale is the most likely layer to experience shearing forces” → Incorrect
- The stratum corneum, the outermost layer of the epidermis, is more exposed to external forces like friction and shear. The stratum basale, being deeper, is relatively protected.
- “The stratum basale is the most likely to get infected” → Incorrect
- The stratum corneum is the most exposed to bacteria and environmental pathogens. While the stratum basale can get infected if a deep wound occurs, it is not the most vulnerable layer.
- “The stratum basale is the least likely layer to make waterproofing keratin” → Incorrect
- Although the stratum basale produces keratinocytes, keratinization mainly occurs in the upper layers, like the stratum granulosum and stratum corneum, where waterproofing proteins form a protective barrier.
Thus, due to its direct connection to the nutrient-rich dermis, the stratum basale has the easiest access to the bloodstream.