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

Carbon cycle, state 3 ways human activities add carbon to the atmosphere

state 3 ways human activities add carbon to the atmosphere

Express an example of directional selection, The peppered moth experiment w...

The peppered moth experiment was an example of directional selection; due to environmental conditions the directional selection shifted from one extreme to the other in 1850s Engla

Proteins, what is he importance of proteins for living beings

what is he importance of proteins for living beings

Who receive any future pandemic flu vaccine, Since the availability of flu ...

Since the availability of flu vaccine is limited, who should receive any future pandemic flu vaccine?

Explain about round worms, Which one of the following statements about cert...

Which one of the following statements about certain given animals is correct? 1. Round worms (Aschelminthes) are pseudocoelomates 2. Molluscs are acoelomates 3. Insects ar

Epidemiological association between hemophilia and HIV, What is the epidemi...

What is the epidemiological association between hemophilia and HIV infection? As hemophilic patients need frequent transfusions of clotting factors (VIII or IX) they are more s

Ecology, does jellyfish depend on solarenergy

does jellyfish depend on solarenergy

Phases of menstrual cycle - reproduction, Phases of Menstrual Cycle - Repro...

Phases of Menstrual Cycle - Reproduction Four phases of the menstrual cycle are usually distinguished: the menstrual, proliferative (follicular), ovulatory and progestational

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