A fundamental difference in the Hypothalamic-Pituitary-Gonadal (HPG) axis between sexes lies in the stability of its feedback. In males, testosterone and its metabolites (like estradiol) provide a steady, constant negative feedback on the hypothalamus and pituitary. This maintains relatively stable levels of GnRH, LH, and FSH, supporting continuous sperm production. In contrast, the female HPG axis is characterized by a dynamic cycle. In the follicular phase, rising estrogen from the developing follicle initially provides negative feedback. However, at a critical threshold, high estrogen switches to positive feedback on the pituitary, triggering the massive LH surge that is essential for ovulation. After ovulation, progesterone and estrogen from the corpus luteum reinstate negative feedback. This cyclical feedback is the basis of the menstrual cycle.

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Zambia

• Joseph Soko – 101 pts

• Visual Pathway Lesions
• Positive and Negative Symptoms
• Hallucinations and Delusions
• Antipsychotic Medications
• Emergency: Environmental Emergencies