What is an opening in the dermis through which perspiration reaches skin?

The opening in the dermis through which perspiration reaches the skin is called a pore. Pores are small openings in the skin that allow sweat to escape from the body. Sweat is produced by sweat glands, which are located in the dermis. When the body is hot, the sweat glands produce sweat, which travels up through the pores and evaporates from the skin. This evaporation process helps to cool the body down.

Pores are also responsible for releasing sebum, which is an oily substance that helps to keep the skin moist and protected. Sebum is produced by sebaceous glands, which are also located in the dermis. Sebum travels up through the pores and onto the skin's surface, where it helps to create a protective barrier against the elements.