reproductive system Flashcards
testes
male gonads that produce sperm
components of system of ducts
epididymis, ductus deferens, ejaculatory ducts, urethra
Accessory glands
seminal vesicles, prostate, and bulbourethral glands
the function of the scrotum
- scrotal location and muscle contraction regulate the temperature of testes
- normal sperm production occurs 2-3 degrees lower than normal body temp
- response to a cooler temperature
muscles contract to pull testes close to the body - in warmer temp - reverse
structure of the testes
- one teste in each sac of the scrotum
- tunica albuginea is located deep to tunica vaginalis which form lobules that contain seminiferous tubules (spermeogenesis)
structure of epididymis
Head, body and tail
Spermatogenic cells
begin sperm production at puberty
Sertoli cells
nourish spermatogenetic cells
Leydig cells
secrete testosterone
structure of spermatozoon
Head - nucleus - acrosome Mid-piece - mitochondria Flagellar Tail
How is spermatogenesis hormonally controlled?
- negative feedback loops control testosterone release and spermatogenesis
- GnRH = increased production at puberty and stimulates secretion of LH and FSH
- LH = secretes testosterone
- FSH = secret ABP
Testosterone
suppresses LH and GnRH secretion
DHT
stimulates the development of external genitals
ABP
binds to and keeps testosterone levels high
inhibin
inhibits FSH secretion
major effects of testosterone and DHT
- prenatal development
- development of male sexual characteristics and sexual function
- stimulation of anabolism
duct of testis
seminiferous tubules
epididymis
- site of sperm maturation and storage
- consists of ductus epididymis
ductus deferens
- terminal portion is the ampulla
- conveys sperm from epididymis towards the urethra
- storage and re-absorption of sperm
spermatic cord
- supporting structure ascends out of the scrotum
- contains duct deferens, blood vessels, nerves, lymphatic vessels, cremaster muscles
ejaculatory ducts
- formed by the duct of seminal vesicle and ampulla of ductus deferens
- eject sperm and seminal vesicle secretion from urethra to exterior
urethra
- shared by reproductive and urinary systems