Final answer:
Epidermal cells undergo several changes as they transition from the basal layer to the skin's surface: they become keratinized, flatten, lose nuclei and organelles leading to apoptosis, and finally form a dead, protective barrier in the stratum corneum.
Step-by-step explanation:
As epidermal cells migrate from the basal layer to the surface of the skin, there are several changes that occur:
- Cells become filled with keratin, a tough fibrous protein, which increases as they move outward. This process is known as keratinization.
- The cells progressively flatten as they move up through the layers of the epidermis.
- Cells begin to lose their nuclei and organelles in the upper layers, leading to cell death, a process called apoptosis.
- By the time they reach the stratum corneum, the outermost layer, the cells are completely dead and form a protective, waterproof barrier that is continually shed.