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

How computed tomography helps the doctors, Explain briefly how computed tom...

Explain briefly how computed tomography (CT) helps the doctors in pinpointing the defects in the patient's body

Protozoa, advantage sand disadvantages of protozoa

advantage sand disadvantages of protozoa

Primary tubercle, Primary  Tubercle  (Ghon Tubercle): When  an  indiv...

Primary  Tubercle  (Ghon Tubercle): When  an  individual with  no  previous exposure  to  tuberclosis inhale a sufficient number of  tubercle bacilli into the alveoli, tubercu

What is crossing over?how meiosis related to this phenomenon, What is cross...

What is crossing over? How is meiosis related to this phenomenon? The Linked alleles for instance, A-b and a- B form the gametes A-b and a-B that maintain the linkage of the al

Tongue grafting, Tongue grafting Top of the stock is cut diagonally ...

Tongue grafting Top of the stock is cut diagonally and in an upward direction. Scion is cut diagonally in downward direction. A second cut is given from above downwards,

Population and sigmoid curve, Name two possible why the number of live bact...

Name two possible why the number of live bacteria cell have reached the stationary growth by 60hrs and start to die off after 12hrs?

Which type of molecule does each of these enzymes break, Besides the pancre...

Besides the pancreatic juice in the intestine there is the releasing of the enteric juice that having digestive enzymes too. What are these enzymes and which type of molecule does

How many g of h2so4 does contain, How many g of H2SO4 does  600 ml of a 1.2...

How many g of H2SO4 does  600 ml of a 1.2 M solution of H2SO4 contain? Please show all steps.

Which joint is stronger-the shoulder or hip joint, In general compare and c...

In general compare and contrast the three functional classifications of joints according to movement. What are two characteristics that make synovial joints unique and different fr

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