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

Sources of water are to contain pathogenic bacteria, What sources of water ...

What sources of water are (a) most likely, (b) least likely to contain pathogenic bacteria?   (a) Water most likely to have pathogenic bacteria will be that which receives u

What are the non-protein ingredients, What are the non-protein ingredients ...

What are the non-protein ingredients The methods utilized for the removal of non-protein ingredients should be such that it should not affect the nutritional and functional pro

Motor control in annelids and arthropods, Motor Control in Annelids and Art...

Motor Control in Annelids and Arthropods In annelids and arthropods generally, individual metameric ganglia of the ventral nerve cord are capable of initiating and keep locomo

Indications for gingival curettage - endodontic surgery, Indications for Gi...

Indications for Gingival Curettage - Endodontic Surgery a) Persistent periradicular pathosis following endodontic treatment, b) Periradicular lesion that enlarges after endo

Explain the difference among dna primase and dna polymerase, Which of the f...

Which of the following is not a difference among DNA primase and DNA polymerase? A. DNA primase can initiate replication of DNA de novo whereas DNA polymerase needs a short oli

Define effect on oestrogens and progesterone in pregnancy, Define effect on...

Define effect on Oestrogens and progesterone in pregnancy? Oestrogens and progesterone are secreted by the placenta from 8-10 weeks of gestation. Progesterone increases through

Explain the localized aggressive periodontitis, Explain the Localized Aggre...

Explain the Localized Aggressive Periodontitis Localized Aggressive Periodontitis: It has been in literature that transmission of peridontopathic microorganisms from periodon

Cell body and cell cycle, Cell body in a neuron, the part which contains t...

Cell body in a neuron, the part which contains the nucleus and most of the cytoplasm and organelles. Cell cycle It is the sequence of events from one division of the cell to

Why pluto is no longer considered a planet, Describe how the International ...

Describe how the International Astronomical Union defines a planet. Also include why Pluto is no longer considered a planet.

What is adaptive convergence?, What is adaptive convergence? The Adapti...

What is adaptive convergence? The Adaptive convergence is the phenomenon by which living beings facing the same environmental pressure (problems) and undergoing genetic variabi

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