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

#title.examples of classes of vertebrates, how to explain an example from e...

how to explain an example from each class of vertebrate

Explain left atrial enlargement, Q. Explain Left Atrial Enlargement ? T...

Q. Explain Left Atrial Enlargement ? This chamber is oval in the frontal projection and flattened in lateral projection. On the PA view, its appendage makes a small contributio

What is meant by the arch reflex, What is meant by the arch reflex? In ...

What is meant by the arch reflex? In some situations the movement of the skeletal striated muscles does not depend upon commands of the superior motor neurons, i.e., it is not

Write the definition of counselling, Q. Write the definition of counselling...

Q. Write the definition of counselling? The counselling process, involves various steps in a sequence as given below: 1. Rapport-Building 2. Locating the Problem 4. Pl

What is meant by the expression infant mortality, What is meant by the expr...

What is meant by the expression 'infant mortality'? Infant mortality refers to the number of babies in a population who die at the age of 1 year or less. It is usually express

Sexual reproduction in eukaryotes, Sexual reproduction in Eukaryotes In m...

Sexual reproduction in Eukaryotes In most eukaryotes, especially higher animals, individuals normally exhibit one or two sex phenotypes; female or male. In such species, females

Determine fat-soluble vitamins recommended for infant, Determine fat-solubl...

Determine fat-soluble vitamins Recommended for Infant? ICMR (1990) does not give recommendations for vitamins D, E and K. As you already know, vitamin D is expected to be met

Explain food borne toxic infections, Q. Explain Food borne toxic infections...

Q. Explain Food borne toxic infections? Ans. The food borne toxic infections, you may recall reading earlier, are caused by the ingestion of a large numbers of ent

How does the hypophysis-corpus luteum negative feedback work, How does the ...

How does the hypophysis-corpus luteum negative feedback work? What is the name given to the atrophied corpus luteum after this feedback process? After ovulation the estrogen an

BIOLOGY , HOW CAN YOU JUSTIFY NEWTON THIRD LAW OF MOTION IN A TYPICAL PLANT...

HOW CAN YOU JUSTIFY NEWTON THIRD LAW OF MOTION IN A TYPICAL PLANT CELL?

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