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

Grazing food chain - food chain, Grazing Food Chain - Food Chain Grazi...

Grazing Food Chain - Food Chain Grazing food chains are quite familiar to most of us. Cow or deer grazing in a field represent a grazing food chain. Similarly, eating of phyto

What essential function do they serve, Why do membranes figure so prominent...

Why do membranes figure so prominently in eukaryotic cells? What essential function do they serve?

Estimation of burn area, Estimation of Burn Area: The  estimation of  ...

Estimation of Burn Area: The  estimation of  the  extent  of  burn area expressed as  the  percentage  of  the surface  area  of  the skin  burnt to  the  total body  surface

What is the relationship between these cells and hiv, Q. What are CD4 lymph...

Q. What are CD4 lymphocytes? What is the relationship between these cells and HIV? How does HIV replicate? The CD4 lymphocytes are T helper lymphocytes that present in their pl

Why nutritional care is recognized as both science and art, Nutritional car...

Nutritional care can be recognized as both a science and art. Can you tell why? It is considered as a science because the raped  advances in scientific knowledge provides all h

Growth curve, typical growth curve in plants

typical growth curve in plants

Explain the energy - releasing metabolic process, The energy - releasing me...

The energy - releasing metabolic process in which substrate is oxidised without an external electron acceptor is known as: 1. Glycolysis 2. Fermentation 3. Aerobic respira

Micro organisums, advantages and disadvantages of protozoa

advantages and disadvantages of protozoa

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