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

Protozoa, what are characteristics of flagellata class ?

what are characteristics of flagellata class ?

Define protection against poisoning - function of vitamin e, Define Protect...

Define Protection against poisoning - Function of Vitamin E? 1) Protection against poisoning: It protects liver from injury due to carbon tetra chloride poisoning. 2) Pr

Psychiatric emergencies, Psychiatric Emergmcy: Psychiatric  Emergmcy i...

Psychiatric Emergmcy: Psychiatric  Emergmcy is  the treatment of disorders of mood, thought and behavior in  an emergency  setting. Psychiatric emergencies are conditions in w

#ti.., what would happen if there is no revolution?

what would happen if there is no revolution?

Determine the photographic analysis, Photographic Analysis Documentatio...

Photographic Analysis Documentation is critical in any clinical procedure and more importantly in this field where due to the cost of the treatment involved, there is little ma

Causes of apomixis, Causes of Apomixis Apomictic species are generall...

Causes of Apomixis Apomictic species are generally hybrids or polyploids, as a consequence, there is irregular meiosis. Apomixis appears to be controlled by a set of genes. T

Of which type of defense cell do viral infections, Of which type of defense...

Of which type of defense cell do viral infections stimulate the multiplication? The major leukocytes that generally multiply and participate in the defense against viral infect

Compound or multilayered epithelia, COMPOUN D EPITHELIA (MULTILAYERED EPIT...

COMPOUN D EPITHELIA (MULTILAYERED EPITHELIA) - These are made up of more than one layer of cells. The compound epithelia may be stratified and transitinal. 1 .

Chambers of the heart, Chambers of the Heart The heart is divided in...

Chambers of the Heart The heart is divided into two halves by a muscular wall or septum, the right heart and the left heart. The function of the right heart is to collect

Natality rate - natality, Natality Rate - Natality Natality rate or bi...

Natality Rate - Natality Natality rate or birth rate is determined by dividing the number of individuals born by unit time and is expressed as follows: Natality rate =  ΔNn

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