Anatomy MCQs: Male genital tract

The questions

1. Where do sperm become able to swim?

   1. In the seminiferous tubules
   2. In the epididymis
   3. In the seminal vesicle
   4. In the prostate
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   Answer: In the epididymis

   They leave the testis immotile and acquire motility over about two weeks in the epididymis — six metres of duct coiled against the back of the testis.

2. Why does an enlarged prostate obstruct the urinary stream?

   1. It presses on the bladder from above
   2. The urethra runs through the gland
   3. It compresses both ureters
   4. It pulls the bladder neck open
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   Answer: The urethra runs through the gland

   The gland grows from buds off the urethra and surrounds it, so the channel is inside the tissue that enlarges.

3. Why do the testes sit outside the abdomen?

   1. To keep them clear of the bowel
   2. To shorten the route to the urethra
   3. Sperm production fails at core temperature
   4. To let the cord rotate freely
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   Answer: Sperm production fails at core temperature

   Two degrees matter: the scrotum, the dartos and cremaster muscles and the countercurrent venous plexus all exist to hold the testis below core temperature.