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Flashcards in Reproductive system Deck (35)
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1

Sequential process of sexual differentiation

1. Establishment of genetic sex 2. Translation of genetic sex into gonadal sex 3. Translation of gonadal sex into phenotypic sex

2

What will happen in an organism if there are ovaries or testis

3

By default we are going to be

Women

i.e The TESTES are essential for male sexual differentiation, but the
ovaries are NOT necessary for female differentiation

4

Pre-requisites for normal sex differentiation

v Normal intact chromosome complement
v Fully functioning sex determination genes
v Intact steroidogenic pathway and receptors

5

Can you change sex in canada?

v As of 2014, several provinces allow birth certificate
changes without sex reassignment surgery being required

6

When in chromosomes male and female phenotype

7

Do sex xhromosomes recombine?

In women all along the chromosome 

In male: only in PAR1 and PAR2 regions

8

SRY gene is very close to recombinant region of PAR, what it can result in 

9

SRY protein has what capacity

To bond to DNA and induce transcription of other genes

10

What is the main target of SRY gene

SOX9 and then other genes-> testicular developemnt -> male

No SRY->other TFs are induced->ovarian development 

11

What centers control secretion of LH/FSH post-puberty in males

Tonic centers that will control GnRH release

12

How the brain becomes male

testosterone can cross brain blood barrier, where it is converted to estradiol, which causes "defeninization" by inhibiting the development of surge centers

13

Why surge centers are important for females?

Female retains surge center and together with tonic centers they control LH/FSH after puberty.

During puberty->surge release of GnRH-> resposnsible for ovulation and reproductive cycle

14

How surge centers are developed in females?

estradiol which is produced in ovaries during embryonic developement is boind to alpha fetoprotein in fetus and thus cannot cross BBB-> surge center develops-> female hypothalamus

15

2 functions of gonads

gametogenesis

hormonogenesis

16

4 main roles of hromogenesis

gametogenesis

electrolyte homeostasis

fuel and protein metabolism

adiposity and muscle mass

17

when increases in testosterone happen in people

fetal, neonatal and then puberty

18

what is happening for the first time during puberty in boys

ejaculation-semenarche

19

what is going on on the level of hypothalamus in puberty

-Before puberty in the females and male, tonic and surge centers release low amplitude and frequency of GnRH

-after puberty the female, tonic center produces higher levels of GnRH because of increased frequency (basal for both male and female). female only-> The surge center controls the preovulatory surge of GnRH

20

Can gonads produce steroids befre puberty?

Yes just at a lower level

21

where axons of GnRH neurons might end

in hypophyseal portal capillaries->anterior pituitary

other brain areas and may affect sexual behavior

22

where GnRH is synthesized apart from the brain

GnRH is also synthesized in the placenta, gonads,
breast, lymphocytes and the pituitary, but function
unknown

23

what is the nature of LH and FSH

glycoproteins

24

how FSH and LH are similar and different

alpha subunit is common and beta is different

25

what can happen to FSH and LH in circulation

Some changes in glycosylation
may occur in circulation →
different isoforms with slightly
different biological properties

26

receptor through which LH and FSH work

G-linked: Activation of
adenylate cyclase and also
phospholipase C

27

in what manner FSH and LH are released

Pulsatile release (in repsonse to GnRH)

28

What happens upon binding of LH and FSH

v Increase of intracellular
cholesterol.
v Transport of cholesterol to the
inner mitochondrial membrane by
StAR
v Conversion to pregnenolone-> steroid production

29

What are target cells for LH and FSH in male and female

v Testis: Only LH is steroidogenic
(acts on Leydig cells).


v Ovaries: Both LH and FSH are
steroidogenic act on two cell
types (theca and granulosa cells)

30

what are 2 types of the cell in oocyte

theca cells

and granula cells that immediately surround the ovum