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

Inadequate dietary intake - cause of anaemia is dietary, Define Inadequate ...

Define Inadequate Dietary Intake - cause of anaemia is dietary? The commonest cause of anaemia is dietary inadequacy of iron. The dietary intakes arc usually half of the recomm

Removal of testis, REMOVAL OF TESTIS - It is male hypogonadism. (1 ...

REMOVAL OF TESTIS - It is male hypogonadism. (1 ) BEFORE PUBERTY - Cestration before puberty results in permanent sterility. This condition is eunuchoidism & shows the

Cells, List structures found in unicellular organisms that are an adaptatio...

List structures found in unicellular organisms that are an adaptation to their free-living life and are not usually found in the cells of multicellular organisms.

State about charles elton, What evidence did Charles Elton collect that sug...

What evidence did Charles Elton collect that suggested that fluctuations in hare and lynx populations were related? What other evidence shows that these fluctuations ma

Auxins, Auxins Auxins are plant growth substances. The term Auxin us...

Auxins Auxins are plant growth substances. The term Auxin usually refers to a chemical compound called Indole Acetic Acid (IAA), which is the major natural auxin. In plan

Deficiency diseases-metabolic disorders, Metabolic Disorders The disea...

Metabolic Disorders The disease conditions, which are attributable to an imbalance between rates of input of dietary nutrients and the output of production, are defined as pro

Major organic molecules for living beings, Q. What are the major purposes o...

Q. What are the major purposes of the organic molecules for living beings? Organic molecules, like, lipids, carbohydrates and proteins perform several functions for living orga

Why the l enantionmer is more dominant, In the Miller-Urey experiment, amin...

In the Miller-Urey experiment, amino acids of bothe the L and D enantionmers. Why is it that the L enantionmer is more dominant in living things?

Explain the alterations occurring in meat and poultry, Alterations occurrin...

Alterations occurring in meat and poultry Meat, as you already know, is  rich in proteins and contains most of the essential amino acids.  It is also rich in minerals such as c

Digestion, In humans, starch digestion begins in the buccal cavity, but sto...

In humans, starch digestion begins in the buccal cavity, but stops in the stomach .Why?

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