Question

In the illustration shown in class about the milk let-down reflex, number 1 corresponds to:

Option 1: Oxytocin release from the pituitary gland.
Option 2: Contraction of mammary gland smooth muscles.
Option 3: Sensory stimulation of the nipple.
Option 4: Milk ejection from the lactiferous ducts.

Answer 1

The milk let-down reflex involves oxytocin release from the pituitary gland, contraction of mammary gland smooth muscles, sensory stimulation of the nipple, and milk ejection from the lactiferous ducts.

Step-by-step explanation:

The milk let-down reflex is a neuroendocrine reflex that occurs when the baby suckles at the breast. This reflex involves several steps:

1. Oxytocin release from the pituitary gland: The sensory nerve fibers in the areola trigger a neuroendocrine reflex that stimulates the posterior pituitary to release oxytocin.
2. Contraction of mammary gland smooth muscles: Oxytocin stimulates the myoepithelial cells to contract, which squeezes milk from the alveoli into the lactiferous ducts.
3. Sensory stimulation of the nipple: The sensory nerve fibers in the areola provide the sensory stimulation that triggers the release of oxytocin.
4. Milk ejection from the lactiferous ducts: The contraction of the mammary gland smooth muscles results in milk being forced from the secretory alveoli into the milk ducts and ejected from the nipples.