How does menstrual cycle begin, Biology

Assignment Help:

Does the hypophysis-ovaries endocrine axis work in the same way during pregnancy as in non-pregnant women? If pregnancy does not occur how does another menstrual cycle begin?

The functioning of the hypophysis is changed during pregnancy. As estrogen and progesterone levels remain elevated during the gestational period the production of GnRH (gonadotropin-releasing hormone) from the hypothalamus is inhibited. The lack of GnRH therefore inhibits the secretion of FSH and LH from the hypophysis and a new menstrual cycle does not start.

If pregnancy does not happen the lowering of estrogen and progesterone levels stimulates the production of GnRH by the hypothalamus. This hormone then hastens the adenohypophyseal secretion of FHS and LH that in their turn stimulate the maturation of follicles and the starting of a new menstrual cycle.

 


Related Discussions:- How does menstrual cycle begin

Eutrophication - effect on water bodies, Eutrophication - Effect on Water B...

Eutrophication - Effect on Water Bodies Moderate quantities of sewage decay naturally in a water body and water gets purified after some time. But the problem arises when the

Listeriosis, Listeriosis The organisms have an extensive host range which ...

Listeriosis The organisms have an extensive host range which includes mammal, poultry, fish, crustaceans and ticks including man. The organism has been isolated from sheep, goats,

Point mutations are caused by substances mutagens explain, Point mutations ...

Point mutations are often caused by substances called mutagens explain? Point mutations are often caused by substances called mutagens. Base analogs, such as 5-bromouracil, a t

Explain puewabilitation programme in details, Explain puewabilitation progr...

Explain puewabilitation programme in details ? Education, counselling, and behavioural interventions are important elements of cardiac rehabilitation. In this guideline, "educ

What is biodiversity, Q. What is biodiversity? The Biological diversity...

Q. What is biodiversity? The Biological diversity is the variety of species of living beings of an ecosystem. In the ecosystems which are more biodiverse, like tropical forests

Define the normal squid intracellular saline, At 1 AM, a researcher places ...

At 1 AM, a researcher places a healthy squid giant axon in a bath of normal squid physiological extracellular saline and internally perfuses the axon with normal squid intracellula

Disadvantage of a monoculture, (a)What do you understand by the term 'monoc...

(a)What do you understand by the term 'monoculture'? (b) What is one disadvantage of a monoculture?   a) 'Monoculture' is the term applied to the growing

Ecology.., write the charecteristics of lake ecosystem

write the charecteristics of lake ecosystem

Define indicators of mg status - total serum mg, Define indicators of Mg st...

Define indicators of Mg status - Total Serum Mg? Several indicators of Mg status have been described. i) Total Serum Mg: Serum Mg concentration are routinely measured to ass

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd