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 are the factors affecting taste quality, Q. What are the factors Affec...

Q. What are the factors Affecting Taste Quality? You may have experienced that the four primary tastes i.e., sweet, sour, salty and bitter are not sensed with an equal ease. Th

Determine the foos sources of cyanocobalamin, Determine the Foos Sources of...

Determine the Foos Sources of cyanocobalamin? Vitamin B I2 is unique among vitamins in the sense that it is mostly found in foods of animal origin but is not generally present

Precautions should be taken while exercising?, Q. Precautions should be tak...

Q. Precautions should be taken while exercising? Being a diabetic the patient has to take a few precautions. These are: - Initiate the exercise programme gently and then bui

Define the term- life on earth, The article entitled "Life on Earth" is try...

The article entitled "Life on Earth" is trying to make the point that RNA likely included before DNA. Forthis article which of the following is false? A. Chains of RNA nucleoti

Mycoplasmosis-poultry, Poultry Mycoplasma gallisepticum causes chronic ...

Poultry Mycoplasma gallisepticum causes chronic respiratory disease (CRD) in chickens. The incubation period is 1-3 weeks. In young birds, the disease is less severe than adult

Incompatibility - pollination and fertilization, Incompatibility - Pollinat...

Incompatibility - Pollination and Fertilization Plants growing under natural conditions have a preference for their mating partners. The stigma of the female parent receives a

Ventilation of gills, Ventilation of Gills Various mechanical devices ...

Ventilation of Gills Various mechanical devices are used to increase the flow of water over the gill's surface. There can be two means of increasing the flow of water over the

Why is it advantageous to have weak hydrogen bonds, Why is it advantageous ...

Why is it advantageous to have weak hydrogen bonds among complementary bases and strong covalent bonds among phosphate and Deoxyribose groups in a DNA molecule? The hydrogen bo

Foot as burrowing organ, Foot as Burrowing Organ The Scaphopoda that ...

Foot as Burrowing Organ The Scaphopoda that usually have burrowing habit, possess foot suitably modified for burrowing purpose. The conical and protrusible foot of Dentalium

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