nipples

Nipples are small, raised projections located at the center of the areola on the chest or breast. They are a normal feature of human anatomy and are present in most people, although size, color, and degree of projection vary widely.

Anatomy: The nipple contains the openings of the milk ducts and underlying smooth muscle that can make the nipple erect. The surrounding areola is usually pigmented and may have small glands (Montgomery glands) that secrete lubricating material. Nerve endings provide sensitivity, and blood vessels supply the tissue.

Development and variation: Nipples develop before birth and persist in both sexes. In females, puberty and hormones cause breast growth and nipple changes. In males, nipples typically do not milk but remain as a structural feature. Variability is common; some people have prominent nipples or inverted nipples.

Function: In individuals who nurse, the nipple is the outlet for milk produced in the breast. Suckling stimulates the let-down reflex, releasing milk through the ducts. Nipples also contribute to sensation and can be sensitive or erogenous for many people.

Health considerations: Nipples can be affected by skin conditions such as dermatitis, and by nipple discharge or persistent inversion, which may warrant medical evaluation. Rarely, diseases such as Paget's disease or breast cancer can involve the nipple. Routine self-checks and medical consultation for persistent symptoms are advised.