Sex differences Flashcards
Name a few types of sex difference
Genetic or chromosomal sex
Gonadal sex
Internal reproductive system
External reproductive system
Pubertal sex changes
Hormonal sex
Brain sex
Behavioural and ‘cognitive’ sex
Sexual identity
What are female sex organs called?
mullerian system
What are male sex organs called?
wolffian system
In the development of MALE sex organs, what does the SRY region on the Y chromosome code for?
a testis-determining factor (a transcription factor
What does the testis-determining factor do?
binds to DNA in cells of undifferentiated gonads and causes them to become testes.
What hormones do the testes produce during the development of male sex organs?
Testes produce hormones that have defeminising (anti-Mullerian hormone) and masculinising (androgens) effects.
What is the Anti-Mullerian hormone?
a A peptide secreted by the foetal testes that has defeminising effects, i.e. inhibits the development of the Mullerian system
What two androgens are the primary causes of masculinisation during early development?
testosterone and dihydrotestosterone
What does Dihydrotestosterone do?
produced from testosterone by 5alpha reductase, acts on androgen receptors in the primordial external genitals (with higher affinity than testosterone) and is critical to stimulate their development into male genitals.
How many amino acid protiens are coded for the SRY region of the Y- chromosone in the Testes determining factor?
230
What can prevent the development of testes?
Point mutations in XY individuals
What does the wolffin system regression require according to recent research?
COUP-TFII, a nuclear receptor, so is not a passive process
What is XY sex reversal?
Point mutations in the SRY region of the Y chromosome result in female sex organs in XY individuals (
What is Androgen insensitivity syndrome?
A condition caused by congenital lack of functioning androgen receptors; in a person with XY sex chromosomes, causes development of a female with testes but no internal sex organs.
What is Turner’s syndrome?
The presence of only one sex chromosome (an X chromosome) results in lack of ovaries but otherwise normal female sex organs and genitalia.
What is Persistent Mullerian duct syndrome?
In an XY individual, congenital lack of anti-Mullerian hormone causes the development of both male and female internal sex organs.
What are axillary and pubic air in females stimulated by?
testosterone produced by cortex of adrenal glandsco
What is puberty triggered by?
Puberty is triggered by hypothalamic secretion of gonadotropin-releasing hormone (GnRH).
What are some steroids?
- Testosterone
- Estradiol
- Progesterone