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

Drugs for hepatitis b, Drugs for hepatitis B Chronic HBV infection is ...

Drugs for hepatitis B Chronic HBV infection is currently treated with interferon alfa, lamivudine or adefovir. Lamivudine is much better tolerated than interferon and much les

Antibody structure, Antibody Structure: An antibody molecule consist of...

Antibody Structure: An antibody molecule consist of two alike light chains ( 220  amino acids each) ad two similar heavy chains (about  440-450  amino acids each) held together

Regulation of glycogen metabolism, Regulation of Glycogen Metabolism It...

Regulation of Glycogen Metabolism It  is  important  for  you  to  understand  that  glycogenesis and gluconeogenesis are regulated  reciprocally. There  is  a  hormonal  regul

Development projects - deforestation, Development Projects - Deforestation ...

Development Projects - Deforestation The use of science and technology to support the ever- increasing needs of man is termed as development. In the recent years, the human po

Phylum Protozoa, Make a detailed study on Phylum Protozoa taking an example...

Make a detailed study on Phylum Protozoa taking an example with clear labeled diagrams.

In dental traumatology-Pulp Tissue revascularization, In Dental Traumatolog...

In Dental Traumatology Traumatic injuries in young kids (8 to 14 years old male > female)  are commonly nowadays. Dental traumatic injuries are mostly in anterior teeth

Biology - a science of exception, BIOLOGY - A SCIENCE OF EXCEPTION - So...

BIOLOGY - A SCIENCE OF EXCEPTION - Some common examples to prove it are - 1.       Embryos of dicot plants have 2 cotyledons but in cuscuta (Dodder plant or amer bel or Aka

Standard invert sugar solution, Q. Standard invert sugar solution? Rea...

Q. Standard invert sugar solution? Reagents Required 1) Standard invert sugar solution: Weigh accurately 0.985 g of sucrose and dissolve in 500 ml of water. Add 2 ml of

Fensom and spanner electroosmotic flow hypothesis, Fensom and Spanner Elect...

Fensom and Spanner Electroosmotic Flow Hypothesis In electroosmosis the ions flow across a membrane in response to electrical gradient. Ions pull along water and other content

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