Anatomy of the Male Reproductive System Flashcards
the genetic sex of an individual is determined at the time of
fertilization by the sex chromosome that is carried by the sperm
there is no morphological indication of sex until
week six or seven of embryonic development
embyro can be described as
sexually bipotential or potentially bisexual
the gonads develop from
embryonic tissue called mesoderm
each gonad is
enclosed by germinal epithelium which surrounds large outer cortex and smaller central medulla
approximately 43 days after fertilization,
Y chromosome begins to affect indifferent gonads
Y chromosome carries a
sex-determining gene that produces testis-determining factor (TDF)
TDF directs
development of indifferent gonads into testes
two pairs of genital ducts are present during
the indifferent stage
mesonephros consists of
mesonephric tubules and mesonephric ducts
production of testosterone causes
mesonephros to differentiate into male reproductive ducts
paramesonephros consists of
a pair of Muellerian ducts
presence of Muellerian-inhibiting factor causes
paramesonephros to degenerate in males
the scrotum hangs from
the lower abdomen behind the base of the penis
scrotum consists of
loose skin, superficial fascia, and muscle tissue located just beneath skin
dartos is
a sheath of smooth muscle fibers
cremaster muscles are
thin strands of skeletal muscle that suspends testes
walls of scrotum contain
numerous sweat glands
a medial septum divides
the scrotum into two compartments, each containing one testis
location of septum can
be seen externally as median raphe
the location of the scrotum outside of the body cavity permits
thermoregulation of the testes to enhance the production and survival of sperm
dartos and cremaster muscles will contract in response to
cold temperatures
-draws testes closer to body to raise temp
dartos and cremaster muscles will relax in response to
warm temperatures
-this moves testes farther away from body to lower their temperature
blood vessels that suppply testes with blood form
pampiniform plexus
pampiniform plexus acts as a
conutercurrent heat exchanger to keep scrotal temp at 35 C
ideal temp
35 C
the testes are the
male gonads
testes are
cytogenic because they produce sperm cells
testes function as
endocrine glands because they produce testosterone
there are two oval testes and each is about
4cm long and 2.5 cm in diameter with a mass of about 15 grams
each testis is covered by
a pair of membranes
tunica vaginalis
lines scrotum
tunica albuginea divides
its testis into 200 to 300 lobules
each lobule contains
several highly coiled seminiferous tubules
each seminiferous tubues is approx
80 cm long
walls of seminiferous tubules contain
Sertoli cells
Sertoli cells protect and nourish
developing sperm cells
Sertoli cells can destroy
defective or damaged sperm cells
Sertoli cells form a
blood-testis barrier
blood testis barrier prevents
sperm from entering blood stream where their membrane antigens could trigger immune response
interstitial cells (of Leydig)
fill the spaces between the seminiferous tubules
interstitial cells of Leydig produce and secrete
testosterone
primary sex cords
finger like strands of germinal epithelium , grow into an indifferent gonad and carry primordial germ cells inward