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

Tanco beans, what is the origin, uses, morphology, active constituents and ...

what is the origin, uses, morphology, active constituents and market perparations ?

Explain the miracidium larva, Explain the Miracidium larva? Miracidium ...

Explain the Miracidium larva? Miracidium is the first stage larva that comes out from the fertilized egg. i) Miracidium is an oval, microscopic, flattened larva which appear

Applications of transgenic animals, A pp l i c a tion s of transgeni...

A pp l i c a tion s of transgenic animals Current applications of gene transfer in farm animals include the improvement of product quality and quantity, disease resistan

Byproducts high in energy and nitrogen, Byproducts high in energy and nitro...

Byproducts high in energy and nitrogen Byproducts in this category include products such as blood meal and poultry offal meal, fish meal, extracted oilseed meals/cakes and wast

Regulation of pyruvate kinase, Regulation of pyruvate kinase, pyruvate carb...

Regulation of pyruvate kinase, pyruvate carboxylase and PEP carboxykinase A) In liver,  pyruvate  kinase  is inhibited  by high levels  of ATP and alanine  so which  glycolysis

Hydrocarbons do not readily evaporate at room temperature, The fact that so...

The fact that some pure solutions of hydrocarbons do not readily evaporate at room temperature is a result of- Select one: a. London dispersion forces. b. The hydrophobic

Proteins, PROTEINS Protein was discovered by Mulder. Berzilius ...

PROTEINS Protein was discovered by Mulder. Berzilius gave the catalytic concept & gave the word protein, which means first rank. Protein holds the 1st place in

Basic calculations during the practical work in laboratory, Define Basic Ca...

Define Basic Calculations during the practical work in Laboratory? Some basic mathematical formulas and conversion factors are given herewith to help you in your calculations d

Explain about the probiotics, Explain about the Probiotics? A mono or m...

Explain about the Probiotics? A mono or mixed culture of living organisms, which when ingested in certain amounts, has a positive impact on host health, beyond conventional nut

Ratios of different samples of nucleic acid, Ratios of the bases in differe...

Ratios of the bases in different samples of nucleic acid yielded the following results: a.  A + C    =   0.6         b.     A  +  C    =  1            c.       A  + G    =  1.2

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