Question

Consider the synchronization of birth and milk production. Babies can be born several months prematurely, and milk production is needed immediately after birth. How has the human body evolved to coordinate this delicate timing of events?
A)The ovaries signal the rest of the body tissues by varying the level of estrogen.
B)Conscious awareness of the arrival of a baby triggers the mother's hypothalamus to secrete prolactin.
C)The hypothalamus and pituitary that triggered the female reproductive cycle also schedule milk production on a nine-month clock basis
D)Oxytocin both causes the uterus to contract in labor and stimulates the release of milk from mammary glands, which is reinforced by prolactin from the pituitary.

Answer 1

It is a hormone and a neurotransmitter that is involved in childbirth and breast-feeding. Empathy, trust, sexual activity all are associated with this hormone. The injection is used to begin or improve contractions during labor.

Complete answer:
-Prolactin and oxytocin are the two hormones that directly affect breastfeeding by the mother to the child. Many other hormones are also used that are involved indirectly in lactation like estrogen.
-Sensory impulse passes from the nipple to the brain when the breast is sucked by a baby for the milk. So in response to the sensory impulse, prolactin is secreted by the anterior lobe of the pituitary gland, and oxytocin secreted by the posterior lobe.
-Due to the stimulation by fetal ejection reflex release of oxytocin takes place which causes the contraction in the uterus wall and also stimulates secretion of prolactin for the production of milk in the mammary gland.

Additional Information: Prolactin (PRL) - it is also called luteotropic hormone or luteotropin. It is a protein that enables mammals to produce milk, especially females. In response to eating, mating, estrogen treatment, ovulation, and nursing it is secreted from the anterior pituitary gland. So it is secreted in pulses between these events. It also performs a major role in metabolism, regulation of the immune system, and pancreatic development.
Oxytocin - is used as a medicine and also as a hormone. It is used to cause contraction of the uterus when used as a medication that causes an increase in the speed of labor, used to start labor, and also used to stop bleeding following the delivery of the baby.
-This hormone is produced by the paraventricular nucleus of the hypothalamus and released by the posterior pituitary.
-It performs a specific role in social bonding, sexual reproduction in both sexes, and during and after childbirth.
-In response to stretching of the cervix and uterus during labor, it is released into the bloodstream as a hormone. It is also released with the stimulation of the nipples from breastfeeding.
-Oxytocin helps in the birth of the baby, and also in the production of the milk.
-The hypothalamus and pituitary that triggered the female reproductive cycle only regulate the menstrual cycle.

So, the correct answer is,” Oxytocin both causes the uterus to contract in labor and stimulates the release of milk from mammary glands, which is reinforced by prolactin from the pituitary.”

Note: -For the secretion of milk by the cells of the alveoli, prolactin is very important. In the blood, the level of prolactin is increased during pregnancy which stimulates the growth and development of the mammary tissue so that it can prepare the production of milk.
-Around the alveoli, the myoepithelial cells made by the oxytocin for the making of the milk which has collected in the alveoli which flow along and fill the ducts.