Sex differentiation & Behaviour Flashcards
(33 cards)
what is sexual differentiation
the biological developmental process of becoming male or female
difference in chromosomes for males and females
males - XY
females - XX
what are some variations of chromosomes
turner syndrome - missing X - female
what are gonads
a part of the reproductive system that releases either eggs for ovaries or sperm for testes
what is the default development
female - the germinal ridge naturally becomes an ovary
what does SRY stand for
sex determining region on the Y chromosome
what does SRY produce
TDF - testes determining factor
what happens when SRY produces TDF
testes form and development moves in a male direction
what is a mutation of a SRY gene that can affect development
Swyer syndrome - male chromosome pattern (XY) but female genitalia
where are progesterone and estrogen made
ovaries
placenta
adrenal glands
what are the morphological sex differences - duct
Müllerian duct system - female sex organs eg fallopian tubes, uterus
Wolffian duct system - male sex organs eg vas deferens
what 2 things do the testes produce to prevent development going in a female direction
testosterone
mullerian inhibitory hormone
what is a mutation of androgen which causes the absence of it called
androgen insensitivity syndrome
what can androgen insensitivity syndrome cause
female development
what is testosterone
hormone that helps with the development and maintenance of male characteristics
what type of cells produce 95% of testosterone in the male body
leydig cells
apart from leydig cells, where is the remaining 5% of testosterone in the male body produced
adrenal glands
where do females produce testosterone
50% ovaries
50% adrenal glands
in the female body, what turns testosterone into estradiol
aromatase - enzyme
what is the process called of converting testosterone into estradiol in the female body
aromatisation
what are gonadotropins
group of hormones secreted by the pituitary gland and control the development of gonads
what 2 hormones is gonadotropin released alongside that help with the development of the gonads
luteinising hormone - sexual development
follicle stimulating hormone - testes and ovaries
how is testosterone regulated in the negative feedback process
- hypothalamus releases GnRH
- Pituitary releases LH and FSH
- FSH and LH signal increase in testosterone
- testosterone increase
- hypothalamus inhibits release of GnRH, LH, FSH
- testosterone gets low again
who found evidence for mounting behaviour in rats
Davidson, 1966
