Male Reproductive Endocrinology Flashcards
what are the two primitive duct systems all embryos have?
Wolffian
MUllerian ducts
In males what occurs in the primitive ducts
Wolffian duct -> repro tract
Mullerian duct degenerate
In females what occurs in the primitive ducts
Wolffian degenerates
Mullerian ducts -> reproductive tract
development into male or female depends upon hormones secreted by foetal testes
what is testosterone stimulated by
human chorionic gonadotropin (hCG) from placenta
what does Mullerian inhibiting factor do
induces regression of mullerian ducts
without stimulus of male testicular hormones, Wolffian ducts do what
and mullerian ducts do what
wolffian ducts regress
mullerian ducts develop and foetus will develop female characteristics
Before week 6 utero, what does testosterone secrete
testosterone and Mullerian-inhibiting factor
What stimulus decreases as the penis is being formed
DHT stimulus
what term is used for the production of sperm
spermatogenesis
what is the route of sperm
testes - epididymis - vas deferens-ejaculatory duct - urethra
T - to
E - eat
V- vagina
E - everyone
U - understand
what is the dual function of the testes
producing sperm and secreting testosterone
Where do leydig cells lie
in connective tissue between seminiferous tubules
what cells lie in connective tissue between seminiferous tubules
leydig cells
in utero where do testes develop
abdominal cavity of foetus
what is the condition where an individual has reached adulthood and testes have not descended
cryptorchidism
why is it important testes descend
lowers temp outside body for spermatogenesis
what is produced in leydig cells
testosterone
testosterone is a steroid hormone derived from where
cholestrol
where is testosterone secrted into for sperm production
blood
seminiferous tubules
when does secretion of testosterone start and end
puberty and for life
what does testosterone do to the reproductive tract before birth
masculinises it and the external genitalia
what is responsible for the descent of the testes into the scrotum
testosterone
what hormone is responsible for the development of libido
testosterone
what hormone controls gonadotropin hormone secretion and through what feedback is spermatogenesis controlled
testosterone
negative feedback
what are some 2 degree sexual characteristics (caused by testosterone and metabolites)
growth of larynx
deepening of voice
increased bone mass
increased mass and strength of skeletal muscle
thickened skin
increased and thickened hair on trunk, arms, legs, face
what is spermatogenesis
conversion of germ cells into motile sperm
what do Sertoli cells do
support spermatogenesis
what are the two cells involved in spermatogenesis
germ cells
sertoli cells
How many stages are there in spermatogenesis
3
name the stages in spermatogenesis
A) mitotic proliferation
B) meiotic division
C) Spermiogenesis
What is the name of spermatocytes after one daughter cell divides twice more
primary spermatocytes (46 chromosones)
what occurs in the 1st meiotic division in spermatogenesis
each primary spermatocyte divides into 2 haploid cells
secondary spermatocytes
what name is given to primary spermatocytes when they divide
secondary spermatocytes
what occurs in the 2nd meiotic divsion
secondary spermatocytes divide t form 2 single stranded spermatids
what hormone is required for mitosis and meiosis stages
testosterone
in the last stage of spermatogenesis (spermiogenesis) what are spermatids converted to
spermatozoa
what happens when spermatids are converted to spermatozoa
removal of unnescessary cellular components and rebuilding into specialised, motile spermatozoa
what hormone is required for the last stage of spermatogenesis
FSH
In the sperm, what contains enzymes for penetration of the ovum
acrosome (the head)
what does the tail provide in sperm
motility
what barrier do sertoli cells form
blood-testes barrier
what is responible for secreting seminiferous tubule fluid
sertoli cells
why do sertoli cells secrete seminiferous tubule fluid
used to carry cells to epididymis along pressure gradient
why do sertoli cells secrete inhibin
inhibin regulates FSH secretion (negative feedback) and control spermatogenesis
during development what do sertoli cells secrete
Mullerian-inhibiting factor
what 2 gonadotropic hormones are secreted by the anterior pituitray
FSH and LH
what does LH do to leydig cells(within testes)
regulates testosterone secretion
where does FSH exert its affect in the testes
sertoli cells to enhance spermatogenesis
secretion of LH and FSH is stimulated by
gonadotropin-releasing hormone (GnRH)
