ANT211H5 Chapter Notes - Chapter 3: Paramesonephric Duct, Fallopian Tube, Y Chromosome
Document Summary
Our sex is ultimately laid down by our genes. What do chromosomes do: x chromosomes specify traits unrelated to sex such as the ability to distinguish red and green, y chromosome contains genes specifying the development of testes. If y (cid:272)hro(cid:373)oso(cid:373)e is prese(cid:374)t, (cid:862)(cid:271)ipote(cid:374)tial(cid:863) go(cid:374)ad starts (cid:271)e(cid:272)o(cid:373)i(cid:374)g testis i(cid:374) 7th week. No y chromosome, gonad waits until 13th week to develop as ovary. 8th week, testes make testosterone some of which is converted into dihydrotestosterone (dht) Androgens convert all-purpose embryonic structures into glans penis, penis shaft, and scrotum: the same structures would otherwise develop into clitoris, labia minora, and labia majora. Embryos start out with 2 sets of ducts mullerian ducts and wolffian ducts. I(cid:374) the a(cid:271)se(cid:374)(cid:272)e of testes, wolffia(cid:374) du(cid:272)ts atroph(cid:455) (cid:449)hile mulleria(cid:374) du(cid:272)ts gro(cid:449) i(cid:374)to a fe(cid:373)ale fetus"s uterus, fallopian tubes, and interior vagina. With testes prese(cid:374)t, a(cid:374)droge(cid:374)s sti(cid:373)ulate the wolffia(cid:374) du(cid:272)ts to gro(cid:449) i(cid:374)to a (cid:373)ale fetus"s se(cid:373)i(cid:374)al vesicles, vas deferens, and epididymis.
