1
Q
descent of testes - process
A
testosterone secreted -> shortening of gubernaculum for testes to come down
2
Q
why need to lower testes?
A
- spermatogenesis temperature sensitive, X occur at normal temperature
- X descend = X produce viable sperms
3
Q
what happens at puberty? (male)
A
1) onset of spermatogenesis
2) enlargement of testes & development of secondary characteristics
3) hormonal changes
4
Q
what hormonal changes happen at puberty? (male)
A
GnRH secretion
- trigger secretion of LH & FSH from anterior pituitary = proper functioning of testes
- by hypothalamus every 1-3 hr
- continuous exposure of gonadotroph to GnRH = densitisation of receptor = decrease LH & FSH release
- negative feedback of testosterone = decrease GnRH release through:
** testosterone act on hypothelamus
** LH stimulate testosterone
** sertoli cell release inhibin
5
Q
how is testosterone formed?
A
1) Leydig cell
- cholesterol -> testosterone
2) Sertoli cells
- testosterone + 5 alpha-reductase -> DHT
- testosterone + aromatase -> estradiol (Female)
6
Q
effects of DHT
A
- external male genitalia differentiation
- sebaceous glands
- male hair pattern
- male hair pattern baldness
- prostate growth
7
Q
male infertility - testicular
A
- problem w sperm production
- trauma, infection, drug intake, chromosomal abnormality
- testes never lower
- absence of tubules/sertoli/leydig cells
- defective 5-alpha reductase
8
Q
male infertility - post testicular
A
problem w storage, transport, nourishment, release
9
Q
male infertility - pre testicular
A
- failure in reproduction function
- GnRH/FSH/LH deficiency
- pituitary tumour
- adrenal insufficiency
- androgen intake = dysregulation of -ve feedback
