PS263 Lecture Notes - Lecture 5: Sexually Dimorphic Nucleus, Paramesonephric Duct, Ventromedial Nucleus Of The Hypothalamus
Document Summary
Male and female start w the same anatomy: mullerian ducts female internal structure, wolffian ducts male internal structure. As well as undifferentiated gonads: testes and ovaries: testes sperm producing. Androgens hormones that increase growth of testes. Sry gene sex determining region on y chromosome: ovaries females egg producing organs. Steroid hormones hormones that contain four carbon rings: bind to membrane receptors, enter cells and activate certain proteins, bind to receptors that bind to chromosomes. Progesterone prepares uterus for implantation of a fertilized ovum and maintains pregnancy. Genes on the x and y chromosomes also produce sex differences. Same unisex structure: internal same, external different. Organizing effects produce long lasting structural effects. Sensitive period sex hormones determine female/male genitals. Activating effects temporary; while hormone is present. Sexually dimorphic nucleus larger in males and contributes to control of male sexual behaviour. Parts of a females hypothalamus generate a cyclic pattern of hormone release.
