HLSC 2P50 Lecture Notes - Lecture 6: Pubic Hair, Menarche, Castrato
13 Oct 2016
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Document Summary
Hormones: chemical substances secreted into the bloodstream (so can go to different parts of the body and acts at different sites) Important sex hormones: testosterone (t) (androgens e. g. , dht), estrogens (e), progesterone. 2 effects: activating (temporary stimulating), organizing (permanent) Receptors: special parts of cell receives/sensitive to hormone. If a cell does not have the receptor: insensitive. 3 important structures: hypothalamus, pituitary, gonads (testes & ovaries) Other hormones: prolactin, oxytocin, pregnancy/birth-related from pituitary. Before any differentiation occurs, the fetus has undifferentiated features, the structure includes gonads, ducts (mullerian & wolffian), early genitals (genital tubercle) At 12-20 weeks: rudimentary (external) genitalia starts to form: outer vagina, clitoris, penis, testes descend, brain differentiation: hypothalamus either goes on the female or male side which affects cycling, gender identity, orientation, sex interests/personality. E. g. , sexually dimorphic nuclei of pre-optic area (sdn-poa) Ovaries & testes are homologous (share embryonic tissue), analogous (share similar features) and produce gametes and sex hormones.
