Question

_______ is released from the stimulated ___________ to initiate milk ejection reflex.

• A. Adrenaline, adrenal gland
• B. Oxytocin, hypothalamus
• C. Prolactin, anterior pituitary
• D. Oxytocin, anterior pituitary

Answer 1

The correct option is B Oxytocin, hypothalamus

There are several hormones that regulate the formation and ejection of milk from the human breast as well as from the breast of other female mammals after giving birth. Among these, there are two primary hormones that are needed for lactation - prolactin and oxytocin.

Oxytocin is produced in the hypothalamus and is secreted into the bloodstream by the posterior pituitary gland. Secretion depends on the neurological activity of the nerve cells in the hypothalamus. Oxytocin is released into the bloodstream when these nerve cells are stimulated. Oxytocin is produced more quickly than prolactin. Oxytocin causes the tiny myoepithelial cells that surround the alveoli to contract and squeeze the milk via small tubes called mammary ducts. These ducts progressively enlarge to end in the nipple and eject the milk from the nipple.

Prolactin secreted by the anterior pituitary gland in the brain is responsible for milk biosynthesis within alveolar cells. Prolactin is essential for the initiation and maintenance of lactation.

An endocrine that is located on top of the kidney and are responsible in secreting hormones like the corticoids and catecholamines is called adrenal gland.