What is the function of oxytocin?

What is the function of oxytocin?

• A. Regulates Circadian Rhythm
• B. Regulates Blood Pressure
• C. Contraction of the Uterus and Ejection of Milk
• D. Stimulates Thyroid Hormone Release

Answer: (C)

Oxytocin’s main role is to act on smooth muscle to drive two essential processes: uterine contractions during childbirth and milk ejection from the mammary glands. It’s made in the hypothalamus and released from the posterior pituitary in response to signals like cervical stretch during labor or suckling. In the uterus, oxytocin binds to receptors on smooth muscle, triggering signaling that raises intracellular calcium and produces contractions; the cycle is reinforced by a positive feedback loop as stronger contractions cause more cervical stretching, leading to more oxytocin release and labor progression. In the breast, oxytocin prompts the myoepithelial cells surrounding milk-producing glands to contract, pushing milk toward the nipple for ejection during breastfeeding. Other options don’t capture these primary actions: circadian rhythms are governed mainly by other signals like melatonin and clock genes, not oxytocin; blood pressure is regulated by multiple systems with factors like vasopressin and autonomic tone playing major roles; thyroid hormone release is controlled by hypothalamic TRH and pituitary TSH, not oxytocin.

Oxytocin’s main role is to act on smooth muscle to drive two essential processes: uterine contractions during childbirth and milk ejection from the mammary glands. It’s made in the hypothalamus and released from the posterior pituitary in response to signals like cervical stretch during labor or suckling. In the uterus, oxytocin binds to receptors on smooth muscle, triggering signaling that raises intracellular calcium and produces contractions; the cycle is reinforced by a positive feedback loop as stronger contractions cause more cervical stretching, leading to more oxytocin release and labor progression. In the breast, oxytocin prompts the myoepithelial cells surrounding milk-producing glands to contract, pushing milk toward the nipple for ejection during breastfeeding.

Other options don’t capture these primary actions: circadian rhythms are governed mainly by other signals like melatonin and clock genes, not oxytocin; blood pressure is regulated by multiple systems with factors like vasopressin and autonomic tone playing major roles; thyroid hormone release is controlled by hypothalamic TRH and pituitary TSH, not oxytocin.