Which gland is responsible for initiating the menstrual cycle?
A. Hypothalamus
B. Anterior Pituitary Gland (APG)
C. Posterior Pituitary Gland (PPG)
D. Ovaries
Correct Answer: A. Hypothalamus
Explanation:-
The gland responsible for initiating the menstrual cycle is the Hypothalamus.
Explanation:-
• The hypothalamus releases Gonadotropin-Releasing Hormone (GnRH).
• GnRH stimulates the Anterior Pituitary Gland to release two important hormones:
• FSH (Follicle-Stimulating Hormone)
• LH (Luteinizing Hormone)
These hormones act on the ovaries, leading to follicle growth, release of estrogen, and eventually ovulation, which together regulate the menstrual cycle.
Summary
Organ / Gland Role
Hypothalamus Initiates menstrual cycle by secreting GnRH
Anterior Pituitary Releases FSH & LH
Ovaries Produce estrogen & progesterone
👉 Therefore, the menstrual cycle begins with hormone signals from the Hypothalamus.
Other Options Details
Here is the description of all options:
A. Hypothalamus
• The hypothalamus is a part of the brain located below the thalamus.
• It plays a major role in maintaining homeostasis and regulating hormonal functions.
• It produces releasing and inhibiting hormones such as GnRH (Gonadotropin Releasing Hormone), TRH, CRH, GHRH, and somatostatin.
• It controls the pituitary gland and regulates body temperature, hunger, thirst, sleep, and reproduction.
B. Anterior Pituitary Gland (APG)
• Also called the adenohypophysis.
• It is controlled by hormones from the hypothalamus.
• It produces and releases important hormones, such as:
• FSH (Follicle Stimulating Hormone) – stimulates follicle growth and sperm production
• LH (Luteinizing Hormone) – causes ovulation and testosterone production
• TSH (Thyroid Stimulating Hormone) – stimulates thyroid gland
• ACTH (Adrenocorticotropic Hormone) – stimulates adrenal cortex hormones
• GH (Growth Hormone) – promotes body growth
• Prolactin – stimulates milk production
C. Posterior Pituitary Gland (PPG)
• Also called the neurohypophysis.
• It does not synthesize hormones but stores and releases hormones produced by the hypothalamus.
• Hormones released:
• ADH (Antidiuretic Hormone) – controls water balance and prevents excessive urine loss
• Oxytocin – stimulates uterine contractions during labor and milk ejection during breastfeeding
D. Ovaries
• Female reproductive organs located on each side of the uterus.
• They produce female sex hormones and ova (eggs).
Hormones secreted:
• Estrogen – responsible for development of secondary sexual characteristics and growth of endometrium
• Progesterone – maintains pregnancy and prepares uterus for implantation
• Inhibin – inhibits FSH production
They play a key role in the menstrual cycle and fertility.
I hope that you liked this article.
Thanks!! 🙏 😊
Writer: Vandita Singh, Lucknow (GS India Nursing Group)