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Sexual Differentiation - Anatomy & Physiology (view source)
Revision as of 09:57, 3 July 2008
, 09:57, 3 July 2008→Internal Genetalia
== Internal Genetalia ==
== Internal Genetalia ==
* Early development of gonads proceeds similarly in both sexes. The gonads are derived from two distinct tissues:
** '''Somatic mesenchymal tissue''' forms the matrix of the gonad
** '''Primordial germ cells''' form the gametes
* '''Genital ridge''' forms from somatic mesenchyme.
* Primordial germ cells migrate to the genital ridge.
* At this stage it is not possible to discriminate between male and female gonads.
* Y chromosomal determination of gonadal sex is only visible when primordial germ cell colonisation is complete.
'''MALE'''
* Sex cord cells proliferate to form the testes cord. During this period '''SRY''' is expressed for the first time within '''Sertoli cells''' (SRY is NOT expressed in primordial germ cells).
* Sex cords with a basement membrane become '''Semniferous Cords''' which give rise to '''Semniferous Tubules'''.
* Within the semniferous cords are two cell populations:
** '''Primordial germ cells''' - Prospermatogonia which give rise to '''Spermatozoa'''
** '''Mesodermal cord cells''' which give rise to '''Sertoli cells'''
== External Genetalia ==
== External Genetalia ==