Exam 3 (Endocrinology) Flashcards
What is a synchronous hermaphrodite?
displays male and female characteristics simultaneously
What is a sequential hermaphrodite?
alternates male and female characteristics
What are the different levels of sex determination/differentiation?
sex determination: genetic sex
1° sex differentiation: gonadal sex
2° sex differentiation: phenotypic sex
What does the hypothalamus release in gamete production?
gonadotropic releasing hormone (hydrophilic)
What does the anterior pituitary release in gamete production?
LH, FSH (hydrophilic)
What do the gonads release in gamete production?
activin (activates FSH)
inhibin (inhibits FSH)
sex steroids (gamete production; inhibit LH)
Describe the first steps in male development
SRY gene → SOX 9 cascade: causes indifferent gonad to develop into testis
What hormones are produced by the testes in male development?
sertoli cells: release anti-Mullerian hormone → Mullerian duct regression
leydig cells: release testosterone
Describe the effects of testosterone in male development
[high] → 2° sex characteristics
[low] → Wolffian development
5a reductase → dihydrotestosterone (DHT) → penis/scrotum development; facial hair
What can inhibit 5a reductase?
Finasteride Rx
What causes Wolffian regression?
lack of high [testosterone] → COUP-TF2 → Wolffian regression
What does aromatase do?
androgens → estrogens
Where is aromatase found?
ovaries (female)
blood (both)
adipocytes (both)
What happens during the organizational phase?
sex hormones → brain → sex-specific CNS organization
What happens during the activation phase?
sex hormones activate sex-specific CNS regions to cause sex-specific behaviors
