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 is cloning, What is cloning? Cloning is the making of an organism ...

What is cloning? Cloning is the making of an organism genetically the same to another by means of genetic engineering. The basis of cloning is the nucleus transplantation ma

Intermediate filaments - cytoskeletal structures, INTERMEDI A T E FILAME...

INTERMEDI A T E FILAMENTS These are non-living structures. Made up of different types of protein eg. Keratin, synemin, desmin and vimentin. These are divided into four

Sources of pollution, There are two main sources of pollution: (1). Nat...

There are two main sources of pollution: (1). Natural Sources:             (a) Volcanic ash             (b) Marsh gas (CH4) released from decay of organic matter.

Explain the difference among dna primase and dna polymerase, Which of the f...

Which of the following is not a difference among DNA primase and DNA polymerase? A. DNA primase can initiate replication of DNA de novo whereas DNA polymerase needs a short oli

What do you mean by an antibiogram, Q. What is an antibiogram? The Anti...

Q. What is an antibiogram? The Antibiogram is a laboratory test intended to guide the choice of sufficient antibiotic to treat a given bacterial infection. In an Antibiogram cu

The hybridization reaction, As double-stranded DNA is heated a temperature ...

As double-stranded DNA is heated a temperature is reached at that the two reaction strands divided.  This procedure is called as denaturation.  The temperature at that half of the

Determine organic material for the energetic metabolism, How are bacteria c...

How are bacteria classified according to the production of organic material for the energetic metabolism? Most bacteria are heterotroph, they do not produce their own food. The

Central and peripheral nervous systems, The brain is only a part of a large...

The brain is only a part of a larger nervous system that extends to each part of the body. The nervous system can be divided into central nervous system (CNS), which consists of th

Define vitamins requirement to avoid underweight problem, Define Vitamins r...

Define Vitamins requirement to avoid underweight problem? Vitamins and Minerals: If the diet provides good amounts of fresh fruits and vegetables, vitamin or mineral supplement

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