The term "corneum" refers to the outermost layer of the epidermis, which is the outermost layer of the skin in vertebrates. It is a vital part of the skin's barrier function, playing a crucial role in protecting the underlying tissues and organs from external factors such as water loss, harmful pathogens, and physical damage.
The corneum is composed of dead, flattened skin cells called corneocytes, which are embedded in a lipid matrix. These corneocytes are formed from living skin cells called keratinocytes that differentiate as they migrate upwards from the deeper layers of the epidermis.
The primary function of the corneum is to prevent excessive water evaporation from the body, maintaining proper hydration levels. It also acts as a shield against the entry of harmful agents like bacteria, fungi, and viruses. Additionally, the corneum provides mechanical strength, flexibility, and toughness to the skin, ensuring its integrity.
The corneum plays a vital role in the natural process of desquamation, which refers to the shedding of dead skin cells from the surface of the skin. This shedding process is essential to maintain a healthy skin appearance and function, allowing for the renewal of skin cells and the removal of damaged or aged cells.
In summary, the corneum is the outermost layer of the skin that acts as a protective barrier, preventing water loss and the entry of harmful agents. It also facilitates the shedding of dead skin cells, leading to the renewal and maintenance of healthy skin.
