Final answer:
Mammary glands are modified sweat glands responsible for producing breast milk. Lactation involves the secretion of milk within alveoli, its movement through lactiferous ducts, and its release via the nipple when a baby suckles. The process is regulated by hormones like prolactin and oxytocin.
Step-by-step explanation:
Glands that pinch off their tips to release their products, such as the milk-producing mammary glands, are an important aspect of human anatomy and reproduction. The mammary glands, which are modified sweat glands, function in the production of breast milk for the nourishment of infants. During lactation, the milk is produced within alveoli, which are clusters of milk-secreting cells that expand and contract depending on the volume of milk present. Surrounding these alveoli are myoepithelial cells that, when stimulated, contract to push the milk through the lactiferous ducts and into lactiferous sinuses, eventually reaching the nipple. From here, the baby can draw out the milk by suckling.
The structure of the lactating breast is detailed, with milk-transporting lactiferous ducts that expand during pregnancy due to various hormones such as estrogen, growth hormone, cortisol, and prolactin. Clusters of alveoli that make up lobules produce the milk in response to hormones, particularly prolactin and oxytocin, which also helps with the milk's release during breastfeeding. Supporting this complex structure are suspensory ligaments and fat tissue, which contribute to breast size but not to milk production capacity.