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

Gene targeting in es cells, Gene targeting in ES cells: In some of the li...

Gene targeting in ES cells: In some of the livestock species pro-nuclear injection cannot be used to modify the animals' own genes due to various reasons especially non availabil

What are the genotypes of all individuals, 1. In cattle, the polled conditi...

1. In cattle, the polled condition (H) is dominant to the horned condition (h). A cross between an individual with red coat (R) and white coat (W) results in roan (RW). A polled, r

Viruses, ae there non-parasitic viruses?

ae there non-parasitic viruses?

Etiologic factor of ulcerative colitis, Q. Etiologic factor of ulcerative c...

Q. Etiologic factor of ulcerative colitis? No single etiologic factor has been identified although genetic auto-immune factors are thought to be involved. Although exacerbation

Implantation, IMPLAN TA TIO N - Attachement of blastocyst on the ...

IMPLAN TA TIO N - Attachement of blastocyst on the endometrium of the uterus is called implantation. Generally it occurs 7th day after fertilisation. (6-10 days). Blas

Pre-operative nursing management of cardiac surgical patient, PRE-OPERATIVE...

PRE-OPERATIVE NURSING MANAGEMENT OF CARDIAC SURGICAL PATIENTS Cardiac surgical patients generally get investigated thoroughly before getting referred to the surgeons. Many of

Epidemiology, The epidemiology of acute rheumatic fever (ARF) is closely co...

The epidemiology of acute rheumatic fever (ARF) is closely connected with that of group-A beta haemolytic streptococcal pharyngitis, both have a maximum incidence in the age group

Cells are miniature chemical factory, Cells is a Miniature Chemical Factory...

Cells is a Miniature Chemical Factory Due  to its incessant metabolic processes, a living   cell earns the  attribute  of a  miniature chemical factory   metabolites and  free

A protein is normally found inside of a lipid bilayer, A protein is normall...

A protein is normally found completely within the inside of a lipid bilayer. The protein likely has: a) Mostly hydrophobic side chains, pointed outwards, with the peptide backbo

What is counsellor, Q. What is Counsellor? Counsellor is someone who gi...

Q. What is Counsellor? Counsellor is someone who gives advice about the problem. A counselor's role is to help patients help themselves. In our context  a counsellor is  a comm

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