Reproductive system

Question 1

Sequential process of sexual differentiation

Answer 1

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

Question 2

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

Answer 2

Question 3

By default we are going to be

Answer 3

Women

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

Question 4

Pre-requisites for normal sex differentiation

Answer 4

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

Question 5

Can you change sex in canada?

Answer 5

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

Question 6

When in chromosomes male and female phenotype

Answer 6

Question 7

Do sex xhromosomes recombine?

Answer 7

In women all along the chromosome

In male: only in PAR1 and PAR2 regions

Question 8

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

Answer 8

Question 9

SRY protein has what capacity

Answer 9

To bond to DNA and induce transcription of other genes

Question 10

What is the main target of SRY gene

Answer 10

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

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

Question 11

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

Answer 11

Tonic centers that will control GnRH release

Question 12

How the brain becomes male

Answer 12

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

Question 13

Why surge centers are important for females?

Answer 13

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

Question 14

How surge centers are developed in females?

Answer 14

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

Question 15

2 functions of gonads

Answer 15

gametogenesis

hormonogenesis

Question 16

4 main roles of hromogenesis

Answer 16

gametogenesis

electrolyte homeostasis

fuel and protein metabolism

adiposity and muscle mass

Question 17

when increases in testosterone happen in people

Answer 17

fetal, neonatal and then puberty

Question 18

what is happening for the first time during puberty in boys

Answer 18

ejaculation-semenarche

Question 19

what is going on on the level of hypothalamus in puberty

Answer 19

• 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

Question 20

Can gonads produce steroids befre puberty?

Answer 20

Yes just at a lower level

Question 21

where axons of GnRH neurons might end

Answer 21

in hypophyseal portal capillaries->anterior pituitary

other brain areas and may affect sexual behavior

Question 22

where GnRH is synthesized apart from the brain

Answer 22

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

Question 23

what is the nature of LH and FSH

Answer 23

glycoproteins

Question 24

how FSH and LH are similar and different

Answer 24

alpha subunit is common and beta is different

Question 25

what can happen to FSH and LH in circulation

Answer 25

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

Question 26

receptor through which LH and FSH work

Answer 26

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

Question 27

in what manner FSH and LH are released

Answer 27

Pulsatile release (in repsonse to GnRH)

Question 28

What happens upon binding of LH and FSH

Answer 28

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

Question 29

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

Answer 29

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)

Question 30

what are 2 types of the cell in oocyte

Answer 30

theca cells

and granula cells that immediately surround the ovum

Question 31

How estrogen can be inhibitory and stimulatory at the same time?

Answer 31

at low concentrations->inhibitory, at high-> positive feedback

Question 32

how follicle grow ? in what pattern

Answer 32

Wave cycle

This is cow, but the same idea

one dominant follicle in the end

Question 33

LH surge is responsible for what in female

Answer 33

Ovulation

Question 34

Hormonal profile during estrous cycle (LH, progesterone, LH, FSH)

Answer 34

Progesterone- from corpus luteum

Estrogen and FSH are high in opposite times

Question 35

How luteal phase is determined

Answer 35

When progesterone concentration is high

when low->follicular