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

Supportive evidence - erythema marginatum, Minor Criteria These are arth...

Minor Criteria These are arthralgia, fever, prolonged PR interval, raised ESR and C-reactive protein levels. In some cases abdominal pain and epistaxis may occur. Other non spec

Describe the role of vntrs in linkage analysis, Question 1: Show applic...

Question 1: Show applications of Bioinformatics in pharmacogenomics. Expand FASTA and BLAST. List out any 10 applications of Bioinformatics in pharmacogenomics Expand

Significance of gastrulation, SIGNIFICANC E OF GASTRULATION - It resul...

SIGNIFICANC E OF GASTRULATION - It results in the formation of three germ layers. It also resutls in the formation of different organs & organ systems. Gastrulation is e

Skin cancer, SKIN CANCER: CAUSES AND TREATMENT PURPOSE: The objective of t...

SKIN CANCER: CAUSES AND TREATMENT PURPOSE: The objective of this assignment is to make you aware of the structure and function of your skin, what are the dangers that your skin ma

Define objective of taxonomy -assemblage of knowledge gained, Define Object...

Define Objective of Taxonomy - Assemblage of Knowledge Gained? A second objective of taxonomy is the assemblage of knowledge gained. This is usually in the form of treatises us

Can you explain reticulum and the rumen, Q. Cows swallow their food once an...

Q. Cows swallow their food once and then this food goes back to the mouth to be chewed again. How can this phenomenon be explained? The food ingested by cows and other ruminant

Explain endonucleases, Explain Endonucleases Endonucleases  are  nucle...

Explain Endonucleases Endonucleases  are  nucleases present  in  the pancreatic juice like RNAase  andDNAase. These hydrolyze internal phosphodiester bonds which are located m

Explain the coenzyme in enzyme catalyzed reactions, Explain the Coenzyme in...

Explain the Coenzyme in enzyme catalyzed reactions? Thiamin functions as the coenzyme thiamin pyrophosphate (TPP) in the inetabolism of carbohydrates and branched- chain amino

Explain identifying features of rhizopus - food microbiology, Explain Ident...

Explain Identifying features of Rhizopus? Macroscopically Rhizopus appears as a white cottony mass (look at rhizopus growth on media above) growing rapidly and spread over enti

Sterilization of apparatus for microbiology experiments, Sterilization of A...

Sterilization of Apparatus for Microbiology Experiments : Containers of dangerous biological materials and the doors leading to laboratories or rooms in which work with pathogenic

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