Spermatogenesis and male infertility* Flashcards
What does the y chromosome have
the sex determining region which assess development of testis from biopotential gonad
what does fetal testes secrete
testosterone
what are the two primitive genital tracts
wolffian and mullein ducts
what causes the development of the male internal genital tract
testosterone and mullerian inhibiting factor
wolffian ducts leads to what in males and what happens to mullerian ducts
repro tract
degenerate
what happens to wolffian ducts and mullerian ducts in females
degenerate
repro tract
when can male/female fetus be differentiated
around 16 weeks
what is androgen insensitivity syndrome link karyotype whats happens in it presentation
testicular feminisation
congenital insensitivity to androgens
x linked
male karyotype 46XY
testis develop but do not descend - androgen induction of wolffian duct does not occur but mullerian inhibition does occur
external genitilia female, absence of uterus and ovaries with short vagina
present at puberty with primary amenorrhoea and lack of pubic hair
where do the testis develop and drop to
why is it important that they descend
how is the testes raises/lowered
abdominal cavity and drop into scrotal sac before birth (androgen dependant)
lower temp outside to facilitate spermatogenesis
nervous reflexes trigger dartos muscle contraction i scrotal sac to lower/raise according to external temperature
what is cryptorchidism
what does it do to the sperm count
does it affect fertility
what operation should be done
individual has reached adulthood and testes have not descended
reduced sperm count
if unilateral then usually fetile
if under 14 then orchideopexy to reduce the risk for testicular germ cell cancer
if adult then orchidectomy
where does spermatogenesis occur
where is testosterone produced from
seminiferous tubules
leydig cells
what are the roles of the sertoli cells
form a blood testes barrier - protects sperm form AB attack, provides suitable fluid composition which allows later stages of sperm development
provides nutrients for developing cells
phagocytosis - removes surplus cytoplasm from packaging process and destroy defective cells
secrete seminiferous tubule fluid - used to carry cells to epididymis
secrete androgen binding globulin - binds testosterone so concentration remains high in lumen - essential for sperm production
secrete inhibit and action hormones - regulates FSH secretion and controls spermatogenesis
FSH and testosterone does what inhibin does what what do sertoli secrete LH does what testosterone leads to what dihydrotestosterone does what
stimulates spermatogenesis decreases secretion of FSH ABG and inhibin stimulus testosterone secretion decreases release of GnRH and LH enlargement of male sex organs and secondary sexual characteristics and anabolism
GnRH is a what type of peptide
where is it released form and how often
leads to what
what inhibits it
decapeptide
hypo in bursts every 2-3 hours begins age 8-12
Ant pit to produce FSH and LH
testosterone
what are FSH and LH LH does what FSH does what stimulated by what inhibited by what what is their production like
glycoproteins
acts on leading cells - regulates testosterone secretion
acts on sertoli cells to enhance spermatogenesis and regulate negative feedback from inhibin
GnRH
testosterone
non-cyclical unlike females
