Here's a breakdown:
* Epidermis: The outermost layer of skin.
* Stratum corneum: The topmost layer of the epidermis, composed of dead, flattened cells filled with keratin.
* Keratin: A tough protein that provides protection and structure to the skin.
Why are these cells dead?
As new skin cells are produced in the deeper layers of the epidermis, they migrate upwards towards the surface. During this journey, they undergo a process called keratinization. Keratinization involves the cells accumulating keratin, becoming flattened, and eventually losing their nucleus and other organelles. This results in the formation of the tough, dead cells that make up the stratum corneum.
The function of dead skin cells:
These dead cells serve as a barrier against the environment, protecting the body from:
* Physical damage: Abrasions, cuts, and other injuries.
* Infection: Preventing pathogens from entering the body.
* Water loss: The stratum corneum helps to keep the body hydrated.
* UV radiation: Keratin helps absorb and scatter UV rays from the sun.
Shedding and renewal:
The dead cells of the stratum corneum are constantly shed and replaced with new cells from the deeper layers of the epidermis. This process of shedding and renewal ensures that the skin remains healthy and functional.
