Final answer:
Breastfeeding benefits nursing infants by providing essential nutrients and immunoglobulins for protection against infections, fostering proper development, aiding digestion, and supporting the mother's postpartum recovery. It also offers a natural contraceptive effect.
Step-by-step explanation:
Breastfeeding offers numerous benefits to a nursing infant. Nutrients found in breast milk are essential for the baby's development and growth. Moreover, breast milk contains immunoglobulins, which play a significant role in protecting the child from bacterial and viral infections. This protection is especially important with the initial secretion known as colostrum, which is rich in antibodies and boosts the infant's immune system shortly after birth.
The act of suckling triggers the release of the hormone oxytocin, which stimulates myoepithelial cells to express milk from the alveoli, moving the breast milk toward the nipple pores for the infant to consume. This positive feedback loop not only ensures that milk production is adequate to meet the infant's demand but also supports numerous developmental processes. Colostrum and subsequent forms of breast milk are perfectly tailored to the infant's needs throughout growth, with breast milk also facilitating digestion and assisting in the excretion of meconium as well as the clearance of bilirubin, reducing the risk of jaundice.
Additionally, breastfeeding prompts mild uterine contractions promoting the return of the uterus to its pre-pregnancy size, and increases metabolic activity in the lactating mother, helping her to consume fat reserves accumulated during pregnancy. Finally, breastfeeding has an amenorrhaeic effect, acting as a natural form of contraception by suppressing the menstrual cycle.