Lecture 38: Reproductive System Development Flashcards
Explain what is meant by the gonads being a “bipotential system”.
The gonads are indifferent at the beginning of reproductive development and retain potential to develop ovary or testis
What is the “default” condition during reproductive development?
Female
What causes the gonad to develop into testis rather than continuing onto the default pathway?
Sry gene on the Y chromosome
What forms from the medulla of the indifferent gonad?
Sex cords, which may give rise to seminiferous tubules
What forms from the cortex of the indifferent gonad?
Ovary
What is the fate of the tunica albugnea in the adult gonad (male and female)?
Male: lies on external surface of testis
Female: internalized in ovary
How are the mesonephric tubules related to the developing gonads?
Males: retained and become efferent ductules
Females: usually degenerate
What is the fate of the Mullerian ducts after gonad is differentiated into testes?
Testis secrete Mullerian inhibiting substance and Mullerian ducts regress
What is the fate of Wolffian ducts after gonad is differentiated into testes?
Testosterone acts on Wolffian (mesonephric) ducts which develop into the ductus deferens
What is the fate of the Mullerian ducts after gonad is differentiated into ovary?
Mullerian ducts “passively” develop as this is the default pathway
What is the fate of the Wolffian (mesonephric) ducts after gonad is differentiated into ovary?
Mesonephric/Wolffian ducts regress
Name the 3 primordia of the external genitalia
Genital tubercle, Genital folds, Genital swellings
What does the genital tubercle give rise to in males and females?
Males: plans penis; Females: clitoris
What do the genital folds give rise to in males and females?
Males: fuse and form shaft of penis; Females: remain unfused and form labia minora
What do the genital swellings give rise to in males and females?
Males: fuse and form scrotum; Females: remain unfused and form labia majora
