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

Osseointegration in immediate placement of implants, Q. Osseointegration In...

Q. Osseointegration In Immediate Placement Of Implants? In routine procedures, delayed placement of implants is done. However, immediate placement of implants into fresh extrac

Diversified animal group of the planet, Q. Which arthropod class is the mai...

Q. Which arthropod class is the mainly diversified animal group of the planet? How can this evolutionary success be explained? The insects are the animal group with most divers

What is the significance of the -r group in amino acid, What is the signifi...

What is the significance of the -R group (variable radical) in an amino acid molecule? The -R group, also known as a lateral chain, is the variable part of the amino acid molec

Flagellated protozoan, Flagellated Protozoan These are protozoan th...

Flagellated Protozoan These are protozoan that move by means of one or more flagella and include the largest number of species, about 6,800.  Asexual reproduction is by

Mitosis, explain mitosis in detail

explain mitosis in detail

What is dyslipidaemia, What is Dyslipidaemia ? The results of epidemiol...

What is Dyslipidaemia ? The results of epidemiological studies, as well as trials with angiographic or clinical endpoints, confirm the importance of various lipid fractions in

Multiple replicons , In the eukaryotes replication of chromosomal DNA happe...

In the eukaryotes replication of chromosomal DNA happens only in the S phase of the cell cycle. As for bacterial DNA, eukaryotic DNA is replicated     figure: The euk

What is cholesterol, Q. What is Cholesterol? In its free, unesterified ...

Q. What is Cholesterol? In its free, unesterified form cholesterol is a major component (together with phospolipid) of cell membranes. Its presence helps to stabilize membrane

Define the term epimerism, Define the Term Epimerism? In addition to D ...

Define the Term Epimerism? In addition to D and L isomerism sugars also exhibit epimerism. Hexoses that differ from each other as a result of variation of H and OH on carbons 2

How is the circulatory system of birds characterized, Q How is the circulat...

Q How is the circulatory system of birds characterized? Like every vertebrate, Birds, have a closed circulatory system. The heart is similar to the mammalian heart, having four

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