According to the two-cell, two-gonadotrophin theory of ovarian steroidogenesis, which pairing of cell type and product is correct?

• A Theca cells produce estradiol directly under FSH stimulation
• B Granulosa cells produce androstenedione under LH stimulation
• C Granulosa cells produce testosterone which diffuses to theca cells for aromatisation
• D Theca cells produce androstenedione under LH stimulation, which granulosa cells aromatise to estradiol under FSH stimulation ✓

Explanation

LH acts on theca cells, which lack aromatase, so they convert cholesterol to androstenedione and testosterone. These androgens diffuse across the basement membrane to granulosa cells, where FSH induces aromatase activity converting them to estradiol. The direction of androgen flow matters: granulosa cells cannot make the androgen substrate themselves, which is why option C reverses the physiology.

Reference: Williams Gynecology, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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