Internal Organs
The presence of keratin-containing epithelial cells is not limited to the skin; they exist throughout the entire body and are found in various glands. In addition to lining the skin, these cells also form the inner lining of the intestines and the ducts that carry secretions from organs like the liver and pancreas. Their role extends beyond providing a physical barrier, as they are involved in separating different tissues and components within the body. For example, epithelial cells contribute to the formation of the blood-urine barrier and play a crucial role in regulating the exchange of molecules, including the absorption of nutrients from the intestines into the bloodstream.
Pathogens: A Closer Look
When it comes to the body’s defense mechanism, keratins play a crucial role in safeguarding against pathogens. These microscopic invaders, including bacteria, fungi, parasites, and viruses, are effectively blocked from entering the body by keratin. Acting as a protective barrier, keratin prevents the majority of pathogens from infiltrating the skin’s outermost layers.
However, in the event that pathogens manage to breach the first line of defense and invade the epidermis, keratinocytes spring into action. These specialized skin cells have the ability to produce chemokines, substances that serve as a distress signal. Chemokines attract leukocyte immune cells to the site of invasion, effectively mobilizing the body’s defense system to destroy the pathogens and halt their progress into deeper layers of the skin.