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

State the term - viral infections, State the term - Viral Infections A ...

State the term - Viral Infections A virus is an encapsulated aggregate of nucleic acid that may be made of either DNA or RNA. Some viruses, such as those causing poliomyelitis

What is radiographic assessment, What is Radiographic Assessment Radio...

What is Radiographic Assessment Radiographic Assessment: Radiographic examination is very different with implants than with teeth. Radiographs are frequently used in implant

Lampbrush chromosomes, LAMPBRUS H CHROMOSOMES Discovered by Rucker...

LAMPBRUS H CHROMOSOMES Discovered by Ruckert . Lampbrush Chromosomes were seen in Oocytes of several different animals like shark, amphibians, reptiles and birds. (Most

What are some examples of secretory cells, What are some examples of secret...

What are some examples of secretory cells? Endocrine and exocrine pancreatic cells, thyroid and parathyroid endocrine cells, adenohypophysis, adrenal and pineal endocrine cell

Describe class aves in details, Describe Class Aves in details? Class ...

Describe Class Aves in details? Class Aves: The fossil record contains evidence that birds evolved from the reptiles. Birds share anatomical features with Protoavis and Archa

Which starch is being broken down by an enzyme, In an investigation to comp...

In an investigation to compare the rates at which starch is being broken down by an enzyme    (a) what test is used    (b) how do you know when the reaction

Community change, Community Change Ecosystems are dynamic entities in ...

Community Change Ecosystems are dynamic entities in which a number of events take place. Associated with the biotic communities of the ecosystem are some changes, which may be

African swine fever, African swine fever African swine fever (ASF), a ...

African swine fever African swine fever (ASF), a highly contagious viral disease of swine and other porcine animals (generally confined to the African continent, part of Weste

Apical ectodermal ridge or aer, Apical Ectodermal Ridge (AER) We have ...

Apical Ectodermal Ridge (AER) We have described earlier that the AER persists at the tip until the last phalangeal cartilage begins differentiation. The following experiments

Inadequate dietary intake - cause of anaemia is dietary, Define Inadequate ...

Define Inadequate Dietary Intake - cause of anaemia is dietary? The commonest cause of anaemia is dietary inadequacy of iron. The dietary intakes arc usually half of the recomm

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