Milk ejection, also known as milk letdown or lactation reflex, is a physiological process that occurs in mammals, particularly in lactating females, to initiate the delivery of milk from the mammary glands. It is a crucial event required for the nourishment of the offspring or to express milk in humans for various purposes.
The process of milk ejection involves the release of the hormone oxytocin from the posterior pituitary gland in response to specific sensory stimuli such as sucking or stimulation of the nipples. Oxytocin acts on the smooth muscles of the milk ducts and milk-producing cells, causing them to contract and squeeze milk into the ducts.
These muscle contractions create a pressure within the mammary glands, resulting in the milk being forcibly ejected or let down into the nipples or teats. This allows the milk to be accessible for the nursing infant or to be collected for human consumption or other purposes.
Milk ejection is a highly coordinated reflexive response that can be influenced by various factors such as maternal emotional state, hormonal fluctuations, and environmental stimuli. It is necessary for the survival and nourishment of newborn mammals and plays a vital role in fostering the bond between the mother and her offspring.
Understanding the mechanisms and cues that trigger milk ejection has practical importance in facilitating breastfeeding, milking animals, or collecting milk for various milk-based products. Techniques such as manual stimulation, breast massage, or the use of breast pumps can be employed to initiate and enhance milk ejection in lactating individuals.
