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

Which are the plant tissues that form the plant roots, Which are the plant ...

Which are the plant tissues that form the plant roots? The roots have a central portion known as medulla made of vascular tissue (inner xylem and outer phloem). The medulla is

Gifted species - biological nitrogen-fixation, Gifted Species - Biological ...

Gifted Species - Biological Nitrogen-Fixation Biological nitrogen fixation remains mainly confined to a few distinct nutritional types of prokaryotes, some of which are free-l

Define resolution - terminologies used in chromatography, Define Resolution...

Define Resolution - terminologies used in chromatography? Resolution is the effectiveness of the separation and is determined by two factors. These include: Distance

What is the advantage of having a family of protein, Why do we need a famil...

Why do we need a family of proteins for cell adhesion (what is the advantage of having a family of proteins?)

Define the starch gel electrophoresis, Define the Starch gel electrophoresi...

Define the Starch gel electrophoresis? Starch gel has the advantage of fine texture and absence of protein adsorption with a molecular sieving effect retarding proteins of larg

Explain the composition of sabouraud agar - culture media, Explain the Comp...

Explain the Composition of Sabouraud Agar? Sabouraud agar is used for cultivation of yeasts and moulds. Peptone - 10.0 gm Dextrose - 40.0 gm Agar - 15.0 gm Distille

What is muscular dystrophy, What is Muscular dystrophy Muscular dystro...

What is Muscular dystrophy Muscular dystrophy :- Defects in the muscle due to faulty nutrition.

Zoonoses disease-transmissible spongif orm encephalopathies, Transmissible ...

Transmissible spongif orm encephalopathies Transmissible spongiform encephalopathies (TSEs, also called Prion diseases) are fatal neurodegenerative diseases such as scrapie of

Explain about catheters and guide wires, Q. Explain about Catheters and Gui...

Q. Explain about Catheters and Guide Wires? The commonly used guide wires vary in diameter from 0.012 to 0.052; with 0.035 or 0.038 being the most commonly used sizes. The stan

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