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

Agro industrial-molybdenum, Molybdenum Although molybdenum functions as a ...

Molybdenum Although molybdenum functions as a component for the enzymes xanthine oxidase, sulfite oxidase and aldehyde oxidase, requirements for it are not established. Molybdenum

Macro µ nutrients, Tabulate macro & micro nutrients on the basis of -...

Tabulate macro & micro nutrients on the basis of -elements, source, synthesis site, symptoms

Name three effects that inbreeding can have on a population, Name three eff...

Name three effects that inbreeding can have on a population. Inbreeding can decrease the number of offspring produced, increase susceptibility to disease, reduce genetic varia

What are the main types of inheritances - epistasis, According to Mendel's ...

According to Mendel's law phenotypical characteristics would be verified by pair of factors (alleles) that separate independently in gametes. What are the main types of inheritance

Genetic defects in dna repair and human disease, Genetic Defects in DNA rep...

Genetic Defects in DNA repair and human disease: 1. Xeroderma pigmentosum is an inherited disease that is characterized by severe photosensitivity and a very high incidence of

What mechanisms would na and water be secreted, When William was helping vi...

When William was helping victims following a devastating earthquake in a region that was not prepared to swiftly set up adequate temporary shelter, he developed severe diarrhea. He

How do dioxins enter the human diet, Normal 0 false false f...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Define radiological anatomy, Q. Define Radiological anatomy? The border...

Q. Define Radiological anatomy? The borders of the mediastinum on the CXR are defined by the contrast produced by adjacent air filled lung. Postero-Anterior View It in

Vaso-constriction, what is a vaso-constriction? what are the effects of vas...

what is a vaso-constriction? what are the effects of vaso-constriction in the skin?

Explain the term - differential reinforcement, Differential reinforcement ...

Differential reinforcement (Training of incompatible behaviour)- Differential reinforcement of incompatible behaviour (DRI) is used to decrease a frequent behaviour without pun

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