BIOL 2410 Lecture Notes - Lecture 19: Labioscrotal Swelling, Paramesonephric Duct, Labia Majora

• School: University of Manitoba
• Department: Biological Sciences
• Course: BIOL 2410
• Professor: Mc Lachlan Elizabeth

Document Summary

Gonads - contain germ cells and produce gametes and sex hormones: germ cells become the eggs or sperm, male gonads - testes - sperm, female gonads = ovaries - eggs (ova) Gametes are haploid 23 chromosomes: 22 autosomal chromosomes and 1 sex chromosome: males xy. Figure 26. 3 - the sry gene directs male development. Sex-determining region of y chromosome in embryonic germ cells (sry gene) produces testis- determining sry protein. Testis-determining sry protein initiates production of multiple proteins that cause gonad medulla to differentiate into a testis which has leydig cells and sertoli cells. Leydig cells secrete testosterone which controls: pushes it to male, development of wolffian duct into accessory structures, development of the male external genitalia - via dht. Sertoli cells secrete anti-mullerian hormone which causes regression of the mullerian duct: represses female. Bipotential stage - the external genitalia of a 6 week fetus cannot be visually identified as male or female: before this - they look identical.