Where is the hair root located in the skin?

The hair root is located in the dermis, which is the second layer of the skin situated beneath the epidermis. The dermis contains the necessary structures that support hair follicles, including blood vessels, nerves, and connective tissue, which are essential for the growth and nourishment of hair. The hair root is part of the hair follicle, which extends down into the dermis, where it receives nutrients and oxygen to facilitate hair growth.

The epidermis, being the outermost layer of skin, does not have the structures required for hair root development. The hypodermis, or subcutaneous layer, is primarily composed of fat and connective tissue and is located below the dermis. While the hypodermis provides insulation and cushioning for the body, it does not house hair roots or follicles. Therefore, the dermis is the correct location for hair roots due to its supportive role in the hair growth process.