Fast block to polyspermy 

Within 1–3 seconds after the binding of the first sperm, the membrane potential shifts from -70mV to about +20 mV

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#Unit 7. System Physiology – Animal

FSH stimulates aromatase in the granulosa cells

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#Unit 7. System Physiology – Animal

LH stimulates cholesterol desmolase in the theca cells

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#Unit 7. System Physiology – Animal

In the granulosa cells,

All the androgens and much of the progesterone are converted into estrogens by the enzyme aromatase

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#Unit 7. System Physiology – Animal

Theca cells synthesize and secrete progesterone.

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#Unit 7. System Physiology – Animal

Three estrogens are present in the plasma of the human female:

1. β-estradiol

2. Estrone

3. Estriol

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#Unit 7. System Physiology – Animal

The principal estrogen secreted by the ovaries is β-estradiol.