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 group specificity, Group  specificity Some enzymes prefer a sp...

Group  specificity Some enzymes prefer a specific functional group to be present\%on  the substrate molecules. Example:- alcohol dehydrogenase  acts on alcohols having  -OH  gr

Explain what an isotonic fluid loss means, Your client has the flu and repo...

Your client has the flu and reports 5-6 loose stools a day. He has experienced an isotonic fluid volume loss. Explain what an isotonic fluid loss means.

How structure of the subunits changed, The holoenzyme is denatured by heat ...

The holoenzyme is denatured by heat at very high temperature. It is found that two polypeptides, although denatured, contains chains that remain together as a unit, while two other

What do you mean by sampling?, Question 1 Explain the essential elements o...

Question 1 Explain the essential elements of Pharmaceutical Manufacturing Question 2 What is pharmacokinetics? Briefly describe the different pharmacokinetic processes that d

What is cyanotic spells, What is Cyanotic Spells ? Hypercyanotic or Cy...

What is Cyanotic Spells ? Hypercyanotic or Cyanotic spell is a pediatric emergency, which requires prompt recognition, and intervention to prevent disabling cerebro-vascular i

Methodology of environmental impact assessment, Environmental impact assess...

Environmental impact assessment consists of 4 phases which are as follows: (i)  Organizing the job. (ii)   Performing the assessment. (iii) Writing the environmental impac

What are proteins and why they are important for us, What are Proteins and ...

What are Proteins and Why they are important for us? We just read that proteins are essential for maintaining and sustaining life. What are proteins or what constitutes protein

Explain about the fat metabolism - ageing, Explain about the Fat metabolism...

Explain about the Fat metabolism - Ageing? With increasing age, the blood cholesterol and blood triglyceride levels gradually increase. Certain factors like the kind and amoun

What are the phases to atherosclerosis, Q. What are the phases to atheroscl...

Q. What are the phases to atherosclerosis? There are five phases to atherosclerosis: Phase I: Asymptomaticphase, consists of fatly streaks which are non-obstructive, lipi

Deficiency diseases-predisposing factors, Predisposing factors The inc...

Predisposing factors The incidence of metabolic diseases in cows and buffaloes increases as the milk production increases and the herd size becomes larger. The highest inciden

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