The breast contains blood vessels, milk ducts, fatty tissue, lymph nodes, and sensory nerves. Beneath the breast lies the pectoral muscle, and its internal structure resembles an upside-down tree. The nipple, which protrudes 0.2 to 0.5 inches, is located at the center of the breast, surrounded by the pigmented area known as the areola. The mammary gland is typically composed of 15 to 20 lobes, each containing milk ducts. These lobes are further divided into smaller lobules, each of which contains 10 to 100 follicles. These follicles are tightly packed around the lobules, with each follicle having its own small milk duct. During pregnancy, the secretion of progesterone and prolactin leads to the secondary development of the breast. Upon entering the lactation period, prolactin is secreted in large quantities, resulting in milk production. The breast is an organ with a rich blood supply. Within the female breast tissue, there is an extensive network of lymphatic vessels that interconnect, forming a dense and intricate lymphatic network that surrounds the entire gland and its lobes.