In the two-cell, two-gonadotropin model of ovarian steroidogenesis, LH acts on theca cells and FSH acts on granulosa cells. Which sequence correctly describes the flow of steroid precursors?

• A Theca cells convert estradiol to testosterone; granulosa cells convert testosterone to cholesterol
• B Granulosa cells produce androgens from cholesterol under FSH; theca cells aromatize androgens to estradiol under LH
• C Theca cells produce androgens from cholesterol under LH; granulosa cells aromatize androgens to estradiol under FSH ✓
• D Both cell types produce estradiol independently from cholesterol, regulated equally by LH and FSH

Explanation

In the two-cell model, LH stimulates theca interna cells to convert cholesterol to androgens (androstenedione). These androgens diffuse to granulosa cells where FSH induces aromatase, converting androgens to estradiol. Option B reverses the cell types. This concept is fundamental to understanding estrogen synthesis and is consistently tested in reproductive physiology.

Reference: Ganong's Review of Medical Physiology, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.