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 a pipette and how is it used, What is a pipette and how is it used?...

What is a pipette and how is it used? There are lots of types of pipettes (or pipette), but most are basically a fancier version of a medicine dropper or eye dropper. They are

Explain identification of cancer cells from normal cells, Explain Identific...

Explain Identification of Cancer Cells from Normal Cells? Cancer cells can be distinguished from normal cells by examining them under a microscope. In a specific tissue cancer

Computed radiography, C omp ut e d radiography: The d...

C omp ut e d radiography: The development of intensifying screen has greatly improved the efficiency of exposure  and has reduced the exposure time.   The fir

What do you mean by the notochord, Q. What is the notochord? How is this st...

Q. What is the notochord? How is this structure formed? The notochord is a rodlike structure that outlines the supporting axis of the embryo and gives birth to the vertebral co

Define interaction of vitamin c with other vitamins, Define Interaction of ...

Define Interaction of Vitamin C with other vitamins? a. Ascorbic acid and other vitamins: Ascorbic acid synthesis is diminished in thiamin and riboflavin deficiency. Vitamin

Explain about suspensions, Explain about Suspensions Sol is a colloidal...

Explain about Suspensions Sol is a colloidal system, in which solid particles are dispersed in a liquid. When the particles of a solid are separated into large aggregates of pa

History of animal taxonomy, Q. Show the History of animal taxonomy? The...

Q. Show the History of animal taxonomy? The beginning of animal taxonomy was made by Aristotle (384-322 B.C.). He extensively studied about anatomy, embryology, habit and ecolo

Energy requirements to get ideal body weight, Q. Energy requirements to get...

Q. Energy requirements to get ideal body weight? Calories: The energy requirements of adult patients is governed by their present body weight and the need to maintain a desira

Explain about congestive cardiac failure, Q. Explain about Congestive Cardi...

Q. Explain about Congestive Cardiac Failure? It is an end stage heart disease and a significant contributor to morbidity and mortality particularly in the elderly population. C

Relate the oxide layer and biocompatibility of titanium, Q. Relate the oxid...

Q. Relate the oxide layer and biocompatibility of titanium? The compatibility of a metal with its host environment depends on its resistance to biodegradation and on the degree

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