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

Define isotope dilution method, Define Isotope Dilution Method? The mea...

Define Isotope Dilution Method? The measurement of total body water (TBW) is based on the principle of hydrometry. You must be aware that water is the most abundant substance i

What are the gynoecium and the androecium, Q. What are the gynoecium and th...

Q. What are the gynoecium and the androecium? What are the other structures of flowers? Androecium is set of male reproductive structures of flowers it comprehends the stamens

Explain the term trans fatty acids, Explain the term Trans fatty acids? ...

Explain the term Trans fatty acids? Plant derived fats and oils contain cis-fatty acids. You may recall reading about the cis and trans isomers in the Nutritional Biochemistry

What is the incubation period of an infection, What is the incubation perio...

What is the incubation period of an infection? Incubation period is the time interval among the infection by an agent that causes disease and the first signs or symptoms of th

Why is this area more vulnerable to damage than others, A small family was ...

A small family was traveling in the car when a minor accident happened. The children in the back seats were wearing lap belts, but still sustained numerous bruises about the abdome

What is the life cycle type of bryophytes, Q. What is the life cycle type o...

Q. What is the life cycle type of bryophytes? As in all plants the life cycle of bryophytes is diplobiontic (alternation of generations) and in bryophytes the lasting form is t

Define ailing and failing, Define ailing and failing Clinically unhealt...

Define ailing and failing Clinically unhealthy implants are classified as "ailing" or "failing". It is necessary to distinguish between an ailing versus a failing implant to de

How the study of fossils strengthen the theory of evolution, How does the s...

How does the study of fossils strengthen the theory of evolution? The study of fossils reveals ancient and extinct species having many same structures to others of the present

Primary consideration in risk management decisions, Protection of  human...

Protection of  human  health should  be  the primary consideration  in risk  management  decisions. Decisions on acceptable levels of risk should be determined primarily by hum

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