Posted by CB on September 08, 2011 at 19:47:53:
In Reply to: Development of the Reproductive System T/F posted by TA Sarah on September 07, 2011 at 09:08:22:
: The Leydig cells produce testosterone which induces the paramesonephric ducts to regress in males. False- Sertoli cells (the other cells within teh seminferious tubules) make MIS (Mullerian inhibiting substance- as this is another name for paramesonephric ducts. Wolffian ducts are the male equivalent (mesonephric ducts).
: The urogenital sinus gives rise to the superior vagina and glans of the clitoris. False- this forms the inferior vagina! The superior vagina comes from the fusion of the paramesonephros. The phallic portion of the UG sinus does give rise to the glans of clitoris though.
: The gonadal ridge is derived from intermediate mesoderm, mesenchyme, and primordial germ cells and forms lateral to the developing mesonephros during the third week of development. False- gonadal ridges form during week five when the mesenchyme and intermediate mesoderm epithelium of the dorsal wall make a gonadal ridge (which is medial to the mesonephros). This does form lateral to the mesonephros, but the germ cells don't make the great trek along the dorsal mesentery until week 6.
: The seminiferous cords become the seminiferous tubules, tubuli recti, and rete testis in males. True. The seminiferous cords come from gonadal (not cortical cords).
: The urogenital folds in females remain unfused forming the labia majora in females. False- the labia majora are unfused labioscrotal swellings. They unite anteriorly and posteriorly as commissures
: The mesonephric ducts form the ductus deferens in males. True- the mesonephric tubules form the efferent ductules.
: Primordial germ cells become mature sperm in males and mature oocytes in females. True- eventually.
: The uterovaginal primordium is unfused cranially forming the uterine tubes and fuse caudally to form the superior vagina and uterus in females. The paramesonephric ducts remain unfused and form the uterine tubes. The uterovaginal primordium is the fustion of the caudal portion of the ducts.
: Sertoli cells in the male testis are responsible for the production of testosterone which is necessary for the development of the mesonephric ducts and external genitalia. False. Leydig cells (which are mesenchyme)
: The primordial germ cells migrate during the 4th week from the cloaca to reach the gonadal ridge. 6th week! And they use the dorsal mesentery... imagine the journey.