male reproductive system Flashcards
mesonephric duct
future male ducts
what do the gonads develop as?
intermediate mesoderm called gonadal ridges
the mesonephric duct becomes…
epididymis, ductus deferens, ejactulatory duct
urogenital sinus
future urethra and bladder lying deep to tubercle
urethral groove
external opening of urogenital sinus running between genital tubercle and anus, laterally flanked by urethral folds and labioscrotal swellings
what does the enlarged genital tubercle form?
penis and urethral folds which fuse to the midline to form penile urethra
what becomes the scrotum?
labioscrotal swellings join the midline
testes
move toward scrotum taking blood supply and innervation with it, pulls layers of the abdominal wall with it
gubernacuium
fibrous cord that attaches to the inferior portion of the testis and floor of developing scrotal sac
processus vaginalis
outpouching of peritoneal lining in the abdomen, pokes through layers of abdominal wall into developing scrotum
what layer of the abdominal wall is not in the testes?
transversus abdominis, layers are not inferior enough
what changes happen to the seminiferous tubules during puberty?
they are closed and then become tube like and are linked to the tubule system
what fuels the growth of the testes?
testosterone and production of sperm
scrotum
sac of skin that extends external to the abdominopelvic cavity, 3 degrees cooler (essential for sperm production)
two muscles of the scrotum
dartos and cremaster
dartos muscle
wrinkle skin of scrotum (external oblique)
cremaster muscle
raise teste closer to body wall in response to cold temperature or sexual arousal (internal oblique)
where is sperm manufactured?
testes, seminiferous tubules (site of sperm production)
epididymis
on organ where sperm is mature, more cord-like, thicker tube, sperm are stored here
pathway for production & ejaculation of sperm
seminiferous tubules –> epididymis –> ductus/vas deferens –> joins ducts of seminal vesicles –> ejaculatory duct –> empties into urethra in prostate –> urethra (inside prostate)
what attaches to the ejaculatory duct in addition to vas deferens?
seminal vesicles, providing fructose that nourishes sperm
accessory sex glands
seminal vesicles, prostate gland, bulbourethral glands
seminal glands
ejaculatory duct, lies between fundus of bladder & rectum, secretes a thick fluid that mixes with sperm as it passes into the ejaculatory duct & urethra
secretions of seminal glands contain
fructose & other nutrients that nourish sperm, other substances to enhance fertilization
ejaculatory ducts
slender tubes that arise by the union of the duct of a seminal gland with the ductus deferens near neck of bladder
prostate gland
encircles the prostatic urethra
prostatic secretions
1/3 of semen volume and contain enzymes that enhance sperm mobility
bulbourethral glands
inferior to the prostate, secrete mucus (pre-ejaculation fluid)
penis
3 columns of erectile tissue, corpus spongiosum, corpora cavernosa
corpus spongiosum
unpaired, urethra running through
corpora cavernosa
paired erectile tissue
glas penis
expanded tip of the penis surrounding the urethral opening, continuous with corpus spongiosum
prepuce (foreskin)
loose fold of skin surrounding the glans to a variable extent
what anchors the penis to the body wall?
bulb and crus
crura
angled portions off to side (ischiocavernosus)
bulb
bulbosponginosus surrounds it
single corpus spongiosum
surrounds urethra, enlarged proximally (root covered by bulbospongiosus muscle) and distally (glans)
paired corpora cavernosa
covered by the ischiocavernosus muscles
what is the function of the muscles corpus spongiosum and corpora cavernose?
maintaining erection and emptying the urethra
fundiform ligament
condensation of abdominal wall fascia (superior attachment of penis to body wall)
erection
sympathetic system- anit erection
parasympathetic system- pro erection (relaxation of smooth muscle allowing blood to flow into erectile tissue)
what happens at the same time during erection?
the expanding erectile tissue puts pressure on the veins adn the bulbospongiosus and ischiocavernosus muscles compress erectile tissue compressing veins decreasing outflow of blood
what are the three parts of erection in males and females?
reflexogenic (stimulation), psychogenic (thought induced), nocturnal (REM sleep)
two phases of ejaculation
emission and expulsion
emission (sympathetic nervous system)
causes semen to be released into ducts, closes neck of bladder so semen components can’t enter allowing them to be released in the ducts
expulsion (somatic nervous system)
mostly from pudendal nerve, peristalsis contractions of muscle, parasympathetic encourages bulbourethral glands to secrete mucus
hypospadias
fusion of urethral folds is incomplete, usually requires surgery to stitch it back up
