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

What event marks the beginning of the menstrual cycle, What event marks the...

What event marks the beginning of the menstrual cycle? What is the blood concentration of FSH, LH, estrogen and progesterone in this phase of the cycle? By convention the menst

Explain human fetal circulation and the adult circulation, Concerning the m...

Concerning the mixture of arterial with venous blood what is the difference between the human fetal circulation and the adult circulation? In the human fetal circulation there

Coniferous forests and taiga, As you travel south from the tundra you will ...

As you travel south from the tundra you will enter the circumpolar belt of coniferous forests which stretches across North America to Eurasia, this region is called taiga, a world

State the enzymes utilization in brewing industry, Enzymes utilization in B...

Enzymes utilization in Brewing Industry Here, the main starting material is malt, produced by allowing barley seeds to germinate under moist conditions. The reserve starch is b

Components of ecosystem, An ecosystem consists of two types of components: ...

An ecosystem consists of two types of components: (a)   Abiotic components: This includes the non-living components of the ecosystem. These are physical and chemical fact

Caseous lymphadenitis, Caseous lymphadenitis Caseous lymphadenitis is a ch...

Caseous lymphadenitis Caseous lymphadenitis is a chronic disease of sheep and goats. It is characterized by abscess formation in lymph nodes and sometimes in lungs and other organ

Explain about lyophilic, Explain about lyophilic If the affinity betwee...

Explain about lyophilic If the affinity between the dispersed phase and the medium is high, the dispersed phase is said to be lyophilic (solvent loving) or hydrophilic, in the

Inhibitor proteins - enzyme-activity control, Inhibitor Proteins - Enzyme-a...

Inhibitor Proteins - Enzyme-activity Control One kind of inhibitor protein found in higher plants is an endopeptidase which degrades nitrate reductase thus causing irreversibl

How does vitamin c act in the body, Q. How does vitamin C act in the body? ...

Q. How does vitamin C act in the body? What is the harm caused by insufficiency of vitamin C? Why was this deficiency also known as "sailors' disease"? Vitamin C, or ascorbic a

Hibernation and aestivation, Normal 0 false false false ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

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