What is the primary substance that composes a layer of the epidermis and plays a role in hardening nails and hair?

What is the primary substance that composes a layer of the epidermis and plays a role in hardening nails and hair?

• A. Collagen
• B. Keratin
• C. Elastin
• D. Melanin

Answer: (B)

The primary substance that composes a layer of the epidermis, specifically involved in the hardening of nails and hair, is keratin. Keratin is a fibrous protein that provides structural strength and resilience to these parts of the body. In the epidermis, keratinocytes produce keratin, which contributes to the protective barrier of the skin and helps to prevent water loss, while also providing a tough, protective layer for hair and nails. Collagen is primarily found in the dermis layer of the skin and provides structural support and strength, but it is not the main component of the outer epidermis. Elastin also resides in the dermis and is responsible for the elasticity of the skin, helping it return to its original shape after stretching. Melanin, on the other hand, is the pigment responsible for skin and hair color, contributing to protection against ultraviolet light but does not play a role in the hardening process of nails and hair.

The primary substance that composes a layer of the epidermis, specifically involved in the hardening of nails and hair, is keratin. Keratin is a fibrous protein that provides structural strength and resilience to these parts of the body. In the epidermis, keratinocytes produce keratin, which contributes to the protective barrier of the skin and helps to prevent water loss, while also providing a tough, protective layer for hair and nails.

Collagen is primarily found in the dermis layer of the skin and provides structural support and strength, but it is not the main component of the outer epidermis. Elastin also resides in the dermis and is responsible for the elasticity of the skin, helping it return to its original shape after stretching. Melanin, on the other hand, is the pigment responsible for skin and hair color, contributing to protection against ultraviolet light but does not play a role in the hardening process of nails and hair.