Final answer:
An erectile nipple becomes hard and protrudes upon stimulation, facilitating breastfeeding by allowing an easier latch-on for the infant. A non-erectile nipple remains flat and soft, potentially complicating the breastfeeding process, which may require special techniques for a better latch.
Step-by-step explanation:
The nipple type that becomes hard, erect, and protrudes upon stimulation, thereby facilitating latch-on, is known as an erectile nipple. This is the ideal type for breastfeeding as it makes it easier for the infant to latch on and receive milk. The process involves a neuroendocrine reflex triggered by the suckling of an infant. Sensory nerve fibers in the areola signal the mother's hypothalamus to release prolactin and the posterior pituitary to release oxytocin. Prolactin stimulates the mammary glands to produce milk, and oxytocin causes myoepithelial cells to contract, squeezing milk from the alveoli into the lactiferous ducts and out through the nipple.
On the other hand, a nipple that remains flat and soft and does not protrude when stimulated is known as a non-erectile nipple. This can complicate breastfeeding as it might be more challenging for the baby to achieve a good latch. There are special techniques and tools that can help with breastfeeding in these cases.