Sexual differentiation in humans any androgen can cause external masculinization. The most potent is dihydrotestosterone (DHT), generated from testosterone in skin and genital tissue by the action of 5α-reductase. A male fetus may be incompletely masculinized if this enzyme is deficient. In some diseases and circumstances, other androgens may be present in high enough concentrations to cause partial or (rarely) complete masculinization of the external genitalia of a genetically female fetus. The testes begin to secrete three hormones that influence the male internal and external genitalia. They secrete anti-müllerian hormone, testosterone, and Dihydrotestosterone. anti-Müllerian hormone (AMH) causes the paramesonephric ducts to regress. Testosterone, which
Trophic hormone causes hyperplasia of enterochromaffin cells which may transform into carcinoid tumors. Trophic hormone Trophic hormone is a hormone that has a growth effect, hyperplasia or hypertrophy, on the tissue it is stimulating. The term "trophic" is from Ancient Greek τροφικός ("trophikós") meaning "pertaining to food or nourishment", here used to mean "growth"; this is the same origin as "atrophy." This should not be confused with "tropic," as in the similar-sounding tropic hormone – the words and concepts are both unrelated. A key example of this is thyroid-stimulating hormone stimulating the thyroid; excess thyroid-stimulating hormone can create a goitre. Trophic hormones