Self-Assessment Questions

6. Phenotypic sex differentiation

• How does the process of differentiation of the male external and internal genitalia differ from testicular descent in regards to stimulation of these two processes?

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  Correct answer:
  Differentiation of the external and internal genitalia relies on exogenous human chorionic gonadotropin (hCG) stimulation to produce testicular androgens (testosterone, dihydrotestosterone) while testicular descent relies on stimulation by fetal gonadatropins. If an abnormality occurs in the fetal hypothalamic–pituitary–testicular axis, the testes will not descend appropriately, resulting in cryptorchidism.