lecture 35 - male reproduction Flashcards
why does the scrotum house the testes away from the body
to maintain a temperature of 34 degrees
what muscle lines the scrotum and what does it do
Dartos muscle
allows the scrotum to wrinkle the skin, pulls it tight to reduce surface tension
what does the cremaster muscle do to the scrotum
contract for heat conservation
what are the spermatic cords
two cords that run between abdomen and testes
what does the venous plexus allow for
thermal exchange between arteries and veins
what are the two corpora cavernosa in the penis and what location are they in anatomical position
main erectile tissue / dorsal aspect
what is the corpus spongiosum and what location is it in anatomical position
contains urethra / ventral aspect
what type of erectile tissue has less erectile tissue
spongiosum
where are the seminal vesicles located
posterior to the bladder
anterior to the ampulla
what percentage of semen is fluid from the seminal vesicles
~60%
where is the prostate gland located
inferior to the bladder
wraps around the prostatic urethra
what % of semen comes from secretion from the prostate
~30%
what are the bulbourethral glands
two glands located in the urogenital diaphragm
what % of semen comes from the bulbourethral glands
5%
what is the last 5% of semen come from
spermatozoa
what is a vasectomy
where the ductus deferens are cut so spermatozoa can not be transported from testes and epididymis up through ductus deferens
what is gametogenesis
formation of gametes
spermatogenesis = males
oogenesis = females
what is spermatogenesis
the process by which spermatogonia are transformed to mature spermatozoa in the seminiferous tubules,
occurs from puberty onwards
explain spermatogenesis I
spermatogonia divide by mitosis into 2 daughter cells
- one spermatogonium (type A) stays at the basement membrane of the seminiferous tubule
explain spermatogenesis II
the second spermatogonia (type B) differeniates into a primary spermatocyte (diploid) which undergoes meiosis I
to form 2 secondary spermocytes (hapliod)
explain spermatogenesis III
these undergo meiosis II to form spermatids
- spermatids differentiate into spermatozoa via spermatogenesis
- spermatozoa released into the lumen
what is gonadotropin
hormone that acts on the gonads
what is the GnRH hormone and where is it produced
gonadotropin releasing hormone produced by the hypothalamus
what is the LH hormone and where is it produced
luteinizing hormone (a gonadotropin) produced by the anterior pituitary
what is FSH hormone and where is it produced
follicle stimulating hormone (a gonadotropin) produced by the anterior pituitary
what is inhibin produced by
from nurse cells
what is testosterone produced by
interstitial endocrine cells
what is testosterone responsible for
male characteristics (maturation of sex organs, spermatogenesis secondary sex characteristics and libido)
what does LH stimulate
the production of testosterone
what do FSH and testosterone control
spermatogenesis
what does FSH stimulate
inhibin production
what does inhibin surpress
FSH
what does testosterone surpress
LH and GnRH
