South Carolina Cosmetology Practice Exam

The subcutaneous tissue, or hypodermis, is primarily composed of a fatty layer. This layer acts as insulation and protects the body's organs and muscles. It also stores energy and helps regulate body temperature. The other options of sweat glands, hair pigment, and keratin and fats are incorrect because they do not make up the main composition of the subcutaneous tissue. Sweat glands are found in the dermis layer of skin, hair pigment is produced by specialized cells called melanocytes in the epidermis layer, and keratin and fats are found in the outermost layer of skin, also known as the stratum corneum. Therefore, while these components may be present in the skin, they are not the primary composition of the subcutaneous tissue.