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 intra enterocyte transport - non-haem iron absorption, Define Intra ...

Define Intra enterocyte transport - non-haem iron absorption? Intra enterocyte transport: In the enterocyte, the absorbed iron can have one of the following metabolic fates:

Describe how enzymes assay is helpful in milk and meat, Describe how enzyme...

Describe how enzymes assay is helpful in milk and meat Wheat seeds a) Determination of  α-amylase, content: an increase indicates sprouting/ germination of stored wheat;

Explain disorders of the gastrointestinal tract, Q. Explain Disorders of th...

Q. Explain Disorders of the gastrointestinal tract? The diseases and disorders of the gastrointestinal (GI) tract. Have you ever suffered from abnormal symptoms of the gastroin

Define the dietary requirements of phosphorus, Define the Dietary Requireme...

Define the Dietary Requirements of phosphorus? We read in the previous section that the requirements of phosphorus are closely linked with those of calcium. The phosphorus req

Differences between electron acceptors and electron carriers, What are the ...

What are the differences between electron acceptors and electron carriers? Give an example of each.

Explain the effect of deficiency of thiamin, Explain the Effect of Deficien...

Explain the Effect of Deficiency of Thiamin? Thiamin deficiency causes the disease beriberi in human beings, which has been classically considered to exist in dry (paralytic) a

Obsessive compulsive disorder (ocd), OBSESSIVE COMPULSIVE DISORDER (OCD): ...

OBSESSIVE COMPULSIVE DISORDER (OCD): OCD is another common neurotic disorder seen in the hospital.  Definition  Obsessive Compulsive Disorder is  the disorder characte

Evolution of heart in higher animals, Evolution of heart in higher animals ...

Evolution of heart in higher animals The circulatory system in higher animals has undergone several changes during evolution. The heart has become totally muscular. Th

What proportion of children with down syndrome, What proportion of children...

What proportion of children with Down syndrome do you expect when women with down syndrome have children with men who have 46 chromosomes Justify your answer

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