Pore is the tiny opening of a skin gland. The glands are like little sacks set deep in the skin. The cells inside the sacks produce sweat if the gland is a sweat gland, and oil if it is a sebaceous gland. The face has many sebaceous glands. The oil that these glands produce is normally a liquid. Blackheads form if the oil cakes (becomes solid) within the pores. If the skin around the blackheads becomes inflamed, acne pimples result. If certain kinds of bacteria get into the pores, they cause boils. A skin rash known as prickly heat develops when sweat glands are blocked up. See also Acne; Perspiration; Prickly heat; Skin.
