The epidermis (outer layer of the skin) needs to be tough and resistant to
The correct answer and explanation is:
The epidermis needs to be tough and resistant to abrasion, pathogens, and dehydration.
The epidermis is the outermost layer of the skin, serving as a crucial barrier between the body and the external environment. Its primary role is to protect the body from various threats, including mechanical damage, harmful microorganisms, and excessive water loss. Let’s break this down:
- Resistance to Abrasion: The epidermis is subjected to constant friction and pressure due to movement, contact with surfaces, and general wear. To withstand this, the outermost layer of the epidermis, called the stratum corneum, is made up of dead skin cells filled with keratin, a tough protein. These cells form a tough, protective layer that shields the underlying tissues from abrasions. As old skin cells are shed, new cells from the deeper layers rise to take their place, ensuring the skin maintains its strength and integrity.
- Resistance to Pathogens: The epidermis also serves as a physical barrier to bacteria, viruses, fungi, and other pathogens that could potentially enter the body. The skin’s acidic pH, along with antimicrobial peptides produced by the cells, adds another layer of defense. The epidermis is also supported by the immune cells that reside within it, such as Langerhans cells, which play a role in detecting and fighting off pathogens before they penetrate deeper layers of the skin.
- Resistance to Dehydration: Another important function of the epidermis is to prevent excessive water loss from the body. The stratum corneum, composed of tightly packed keratinocytes, forms a waterproof barrier. Lipid-rich layers in the skin also help to reduce water evaporation. This barrier is essential to maintain proper hydration levels and prevent dehydration, particularly in dry or hot environments.
In conclusion, the epidermis is specialized to be tough and resistant, ensuring it performs its protective roles effectively. Without these attributes, the body would be vulnerable to physical damage, infections, and dehydration.