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

Illustrate physiological evidence, Q. Illustrate Physiological Evidence ? ...

Q. Illustrate Physiological Evidence ? Physiological and biochemical evidence is providing data of increasing importance to plant systematic. Recently, it has become apparent t

Explain nutrient requirement and dietary management, Explain Nutrient Requi...

Explain Nutrient Requirement and Dietary Management? You must have understood by the discussion above that by the end of the flow phase, the patient usually is well hydrated an

What proportion of the offspring of cross, Assuming independent assortment,...

Assuming independent assortment, what proportion of the offspring of the cross AaBbCcDd × AabbCCdd will have the aabbccdd genotype?

Define the disc electrophoresis, Define the Disc Electrophoresis? Disc ...

Define the Disc Electrophoresis? Disc electrophoresis has improved resolution and strong bands are obtained. It requires a two-gel system and several different buffers. The run

Rabbit, reproductive system of rabbit

reproductive system of rabbit

Zonation in the ocean, Q. Zonation in the ocean? The oceans play a majo...

Q. Zonation in the ocean? The oceans play a major role in determining the climate and sustaining life on earth. Oceans help to redistribute the solar energy, through ocean curr

Describe the filaments in the muscle fiber, Describe the filaments in the m...

Describe the filaments in the muscle fiber A healthy skeletal muscle fiber is isolated and has no external forces on it. It has normal intracellular levels of ATP and is bathed

Action of antibodies against virus and against bacteria, Q. How different a...

Q. How different are the actions of antibodies against virus and against bacteria? Why is the cellular immune response activated in case of chronic viral infection? The antibod

Hard paste removal-therma-fill, Hard paste removal -    Hard setting Ca...

Hard paste removal -    Hard setting Ca(Ho) 2 paste (like Endocal 10) can be softened by EDTA and removed by file or microdebrider. -    Care must be taken not to gouge or

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