HDFS 240 Lecture Notes - Lecture 3: Congenital Adrenal Hyperplasia, Umbilical Cord, Sexual Differentiation
12 Feb 2018
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Document Summary
Most cells in human body have 46 chromosomes (23 each from father and mothers) One pair are sex chromosomes (determine whether the person is male or female) Physical sex is determined at moment of conception. Many things impact the process of sexual differentiation. Development of sexual characteristics occurs in utero. Internal sex organs: first few weeks of development (xy and xx embryos identical) During 5th/6th week: primitive gonads, become testes or ovaries. Once gonads develop: hormones control development of ducts. External sex organs: male and female genitalia develop from the same tissue (until the 8th week, a mound of skin underneath the umbilical cord) When the testes begin to secrete androgen, stimulates development of male gen. Hormones affect development of the brain (in utero, after birth) Female brains: signal monthly release of females. Male brains: signal continual release of hormones. Sexual diff. of the genitals: early in pregnancy. Sexual diff. of the brain: later in pregnancy.
