Male Reproductive Physiology and Pharmacology Flashcards
WHere does spermatogenesis happen?
in the seminiferous tubules of the testicles
Where in the tubule are the spermatogonia located?
closest to the basement membrane - they move further in as they develop with spermatozoa at the very inner portion
SPermatogenesis is staggered throughout the seminiferous tubules sot hat all developmental phases are present at any one time. What is a spermatogenic wave?
defined as the time (distace) it takes for the reappearance of the same stage within a given segment of the seminiferous tubule
Why is this important?
it ensures that spermatozoa are produced continuously so that mature speram are always available for when the male finds a ready female
Because of spermatogenic waves, drug or environmental conditions that affect spermatogenesis may be measureable for how long?
up to 2 months post insult
What is the average daily sperm production?
about 100 million
Spermatogenesis is positively correlated with what hormone?
testosterone levels
How long does it take for the mitosis stage?
16 days
How long doe sit take for the first meiosis?
24 days
How long does it take for the second meiosis
only a few hours
How long does spermiogenesis take?
24 days
What does GnRH trigger in the males
anterior pit release of FSH and LH
What does FSH and LH do in the male?
make testis produce testosterone
Testosterone has negative feedback at what levels?
both hypothalamus and anterior pituitary
What cell does the LH bind to in the male?
leydig cell
What does this promote?
production of testosterone
What does the FSH bind to in the male?
sertoli cells
What does this trigger?
- makes androgen binding protein to increase concentratin of testosterone
- production of inhibin
WHat do the sertoli cells do for the developing sperm?
- protects them from plasma
- nrouishes them
- secretes luminal fluid and provides androgen binding protein
- secretes paracrine agents that stimulate sperm proliferation and differentiation
- make inhibin
- paracrine signals to leydigs
- phagocytize defective sperm
- secrete mullerian inhibitin substance
Low sertoli cells numbers are associated with….
low spermatogenesis
Low leydig cell numbers are correlated with what hormone levels?
decreased testosterone levels
increased gonadotropin levels (lack of negative feedback)
WHat are some symptoms of decreased testosterone (andropause)?
decrease in testicular function
erectile dysfunction
weight gain
gynecomastia
How do we diagnose androgen deficiency?
total testosterone level
may follow up with FSH/LH
What are the treatment optoins for androgen deficiency?
hormone replacement
sleep, eat, exercise
viagaral for ED
WHat are the thre emain natural androgens?
androstenedione
testosterone
dihydrotestosterone
What tissues will be affected by targeting testosterone?
muscle
seminal vesicle
epididymis
boen