Which hormone secreted from pituitary gland, that stimulates ovary to secrete estrogen in adolescence period?

RRB Nsg. Superintendent -29 April-2025 (shift-2nd)

Applied Physiology

Medium

Appeared in: RRB Nsg. Superintendent -29 April-2025 (shift-2nd)

Explanation

Luteinizing hormone (LH) is a gonadotropin released from the anterior pituitary gland that is essential for ovarian steroidogenesis (hormone production).
According to the 'Two-Cell, Two-Gonadotropin Theory,' LH specifically stimulates the theca cells of the ovarian follicle to produce androgens.
These androgens serve as the direct precursors for estrogen. They are converted to estrogen in the adjacent granulosa cells (a process stimulated by FSH).
The onset of puberty is marked by an increased pulsatile release of LH, particularly during sleep, which initiates this cascade leading to estrogen secretion and the development of secondary sexual characteristics.

Option A: Growth hormone (GH) is primarily responsible for somatic growth (bones, tissues) and metabolism. It does not directly stimulate the ovaries to produce estrogen.
Option B: Adrenocorticotropic hormone (ACTH) stimulates the adrenal cortex, not the ovaries. It leads to the production of cortisol and adrenal androgens, which contribute to pubarche (pubic hair growth) but not ovarian estrogen.
Option D: Prolactin's main function is to stimulate milk production after childbirth. In fact, high levels of prolactin (hyperprolactinemia) can suppress the release of LH and FSH, thereby inhibiting ovulation and reducing estrogen levels.

Visual 1: Diagram: The Two-Cell, Two-Gonadotropin Theory - An infographic showing a theca cell and a granulosa cell, illustrating how LH stimulates androgen production in the theca cell and FSH stimulates estrogen conversion in the granulosa cell.
Visual 2: Flowchart: The Hypothalamic-Pituitary-Ovarian (HPO) Axis - A chart showing the sequence from GnRH in the hypothalamus, to LH/FSH in the pituitary, to estrogen/progesterone in the ovaries, including feedback loops.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Hormonal regulation of female puberty and ovarian function as background academic context rather than a clinical decision trigger.
Measuring LH levels is a key component of infertility workups and the diagnosis of various endocrine disorders.
An elevated LH to FSH ratio (e.g., 2:1 or 3:1) is a classic, though not universal, finding in Polycystic Ovary Syndrome (PCOS), a common cause of anovulation and infertility.
LH measurement is used in ovulation predictor kits, which detect the mid-cycle LH surge that precedes ovulation by 24-36 hours, helping individuals time intercourse for conception.

How to Approach the Question

First, identify the key components of the question: the source (pituitary gland), the target (ovary), and the action (secrete estrogen).
This points to the Hypothalamic-Pituitary-Ovarian (HPO) axis, which governs female reproduction.
Recall the major hormones of the anterior pituitary and their primary functions.
Eliminate hormones with unrelated primary functions. Growth hormone is for growth, ACTH is for the adrenal gland, and Prolactin is for lactation.
This leaves Luteinizing hormone (LH). Recall that LH and FSH are the two gonadotropins that act on the gonads (ovaries).
Remember the 'Two-Cell Theory': LH stimulates theca cells to make androgen precursors, which are then converted to estrogen. This confirms LH as a direct stimulator of the estrogen production pathway.

Concept Tested & Keywords

Concept Tested: Hormonal regulation of female puberty and ovarian function.
Stem keywords: hormone, pituitary gland, stimulates ovary, secrete estrogen, adolescence
Lead-in keywords: Which
Negative lead-in flag: false

QZDJOnvLOsMeNruufWEHdM