BIOL 2040 Study Guide - Quiz Guide: Estrous Cycle, Photoacoustic Imaging, Twin
14 Mar 2017
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Document Summary
Peptide hormones: water-soluble, amino acid chains, bind to membrane receptors, affect cell membrane properties and protein function. Steroid hormones: fat-soluble, derived from cholesterol, enter the cell, bind to intracellular receptors, enter nucleus, affect gene expression. Secreted primarily from the gonads and adrenal glands. Broad (reach all receptors to initiate tissues) response) Organizational effects: act on the formation of neural pathways responsible for certain behaviours (early in life, permanent). Activational effects: stimulate existing neural systems responsible for mediating specific patterns of behaviour (adulthood, transient). Rat sexual behaviour: males (mounting, intromission, ejaculation), females (solicitation, lordosis). Due to differences in the organization of neurons induced by actions of testosterone and estradiol. However, estradiol does not make it to the brain from the blood as it is bound by alpha-fetoprotein (does not bind testosterone). Intrauterine position: secretions of testosterone from male embryos can contaminate embryos directly beside them in the uterus.
