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

Portal hypertension, Portal Hypertension: If you review the portal cir...

Portal Hypertension: If you review the portal circulation you may recall that normal blood flow to and from the liver depends on proper functioning of  the portal vein, the he

State diploblastic in brief, State Diploblastic in brief. Organisms for...

State Diploblastic in brief. Organisms formed from only two primitive cell layers- ectoderm and endoderm. Though there may be some type of a matrix between two cell layers, gen

What is the endocrine function of the placenta, Q. What is the endocrine fu...

Q. What is the endocrine function of the placenta? The placenta is not a permanent gland of the endocrine system other than this it also has endocrinal function. The placenta p

Explain the sedimentation - air sampling, Explain the Sedimentation - Air S...

Explain the Sedimentation - Air Sampling? It is the simplest method, which involves exposing agar plates in air for specified time at a location to be sampled.  Microorganisms

Explain radial symmetry in classification animal kingdom, Explain Radial S...

Explain Radial Symmetry in Classification of the Animal Kingdom? All of the animals besides the sponges are considered to belong to the Eumetazoa, or the "true animals" because

Phenotypical proportion obtained in f2 generation explained, Considering th...

Considering the hybridization in a given trait like the color of the hair of a mammalian species (white/black) conditioned by a pair of different alleles under complete dominance (

Porifera, how to write character of porifera

how to write character of porifera

Peroxisome and lysosome, e use itwhat is difference between peroxisme and l...

e use itwhat is difference between peroxisme and lysosome what is function of it and where w

Topical route for injection, Topical Route The medication in topical r...

Topical Route The medication in topical route is administered through ear, nose and eye. Drops are instilled into the nose, ear and eyes of the child in much the same way

Theileriosis, T h e i l e r io s i s It is also referred as t...

T h e i l e r io s i s It is also referred as tropical theileriosis and results in fever, enlargement of superficial lymphnodes, anaemia and jaundice. E tiolo

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