IC3

Question 1

descent of testes - process

Answer 1

testosterone secreted -> shortening of gubernaculum for testes to come down

Question 2

why need to lower testes?

Answer 2

• spermatogenesis temperature sensitive, X occur at normal temperature
• X descend = X produce viable sperms

Question 3

what happens at puberty? (male)

Answer 3

1) onset of spermatogenesis
2) enlargement of testes & development of secondary characteristics
3) hormonal changes

Question 4

what hormonal changes happen at puberty? (male)

Answer 4

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

Question 5

how is testosterone formed?

Answer 5

1) Leydig cell
- cholesterol -> testosterone

2) Sertoli cells
- testosterone + 5 alpha-reductase -> DHT
- testosterone + aromatase -> estradiol (Female)

Question 6

effects of DHT

Answer 6

• external male genitalia differentiation
• sebaceous glands
• male hair pattern
• male hair pattern baldness
• prostate growth

Question 7

male infertility - testicular

Answer 7

• problem w sperm production
• trauma, infection, drug intake, chromosomal abnormality
• testes never lower
• absence of tubules/sertoli/leydig cells
• defective 5-alpha reductase

Question 8

male infertility - post testicular

Answer 8

problem w storage, transport, nourishment, release

Question 9

male infertility - pre testicular

Answer 9

• failure in reproduction function
• GnRH/FSH/LH deficiency
• pituitary tumour
• adrenal insufficiency
• androgen intake = dysregulation of -ve feedback