PSY 1 Chapter Notes - Chapter 11: Paramesonephric Duct, Sexually Dimorphic Nucleus, Vas Deferens
Document Summary
Sexual reproduction increases variation and thereby enables quick evolutionary adaptations to changes in the environment. The male"s y chromosome includes the sry (sex- determining region on the y chromosomes), which causes the gonads to become testes (sperm producing organs) Testes also produce mih (mullerian inhibiting hormone): mullerian ducts degenerate. Androgen and estrogen are steroid hormones, containing 4 carbon rings derived from cholesterol. Steroids: bind to membrane receptors, exerting rapid effects, enter cells and activate certain kinds of proteins in the cytoplasm, bind to receptors that bind to chromosomes, where they activate/ inactivate certain genes. Most widely known estrogen: estradiol and progesterone. Progesterone: prepares the uterus for the implantation of a fertilized ovum and promotes the maintenance of pregnancy. Organizing effects: producing long lasting structural effects, most prominent effects occur during early development (before birth) Sensitive period: when hormones determine whether an embryo develops male/female anatomy.
