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

Explain the nutritional factors that affecting food choice, Explain the Nut...

Explain the Nutritional Factors that affecting food choice? Food choices made based on sound principles of nutrition will be conducive to good health while carelessness about n

Are hookworms monoxenous or heteroxenous, Q. Are hookworms monoxenous or he...

Q. Are hookworms monoxenous or heteroxenous? The Monoxenous are Hookworms that is their life cycle depends only on one host.

What is the significance of magnesium for plants, What is the significance ...

What is the significance of magnesium for plants? What are the other main biological functions of magnesium? Magnesium is fundamentally significant for plants because it is par

Nucleic acids, Deoxyribonucleic Acid (DNA) - polymer of nucleotides contai...

Deoxyribonucleic Acid (DNA) - polymer of nucleotides containing genetic information that codes for proteins Nucleotide - a monomer of DNA consisting of a ribose/deoxyribose sug

Tolrance, geographical range graph on minimum and maximum range of toleranc...

geographical range graph on minimum and maximum range of tolerance

What is placoid scale. elaborate in detail., What is Placoid scale? Elabora...

What is Placoid scale? Elaborate in detail. Scales characteristic of cartilaginous fish. Formed from the dermis, scale is anchored in that layer by a basal plate composed of de

Explain the mechanism of drying, Explain the Mechanism of Drying? Dryin...

Explain the Mechanism of Drying? Drying as a mechanism, you will realize, involves the removal of free moisture from the surface and also moisture from the interior of the mate

What are passive and active immunization, What are passive and active immun...

What are passive and active immunization? According to the duration of the protection how do these types of immunization differ? Active immunization is that in which an antigen

State the term - infection, State the term - Infection Infection is th...

State the term - Infection Infection is the invasion of the body by disease-producing (pathogenic) microorganisms and the reaction of the tissues to their presence and to the

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