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

What is cartilage explain briefly, What is Cartilage explain briefly? S...

What is Cartilage explain briefly? Some bones, such as the bones in the skull, develop directly from membranous connective tissue, but in human fetal development, most of the s

Explain Genetic equilibrium for genes with two alleles, What is the mathema...

What is the mathematical expression of the genetic equilibrium for genes with two alleles? Is this statistical distribution the same as the statistical distribution of the respecti

Describe the electron transport system, a) Describe the electron transport ...

a) Describe the electron transport system. Where does it happen in a mitochondrion and what is the role of oxygen in it ? b) Explain the events that happen in the human heart du

Monosaccharides and disaccharides, Monosaccharides are frequently known as...

Monosaccharides are frequently known as single or simple sugars and are the easiest of all carbohydrates. That is the building blocks of all higher carbohydrates. The Monosacchari

Spatial conformation like an enzymatic substrate, Q. For the enzymatic reac...

Q. For the enzymatic reaction what is the effect of a substance with the same spatial conformation like an enzymatic substrate? How is this kind of substance known? Substances

Which animals make cutaneous respiration, Q. Which animals make cutaneous r...

Q. Which animals make cutaneous respiration? Adult amphibians and Terrestrial annelids make cutaneous respiration in amphibians there is also pulmonary respiration, the thin sk

In vitro fertilisation that involves into the fallopian tub, In vitro ferti...

In vitro fertilisation is a technique that involves transfer of which one of the following into the fallopian tube? 1. Embryo only, upto 8 cell stage 2. Either zygote or ear

Explain about pantothenic acid, Pantothenic acid (Calcium pantothenate) ...

Pantothenic acid (Calcium pantothenate) Calcium pantothenate is a white, loose, faintly hygroscopic powder without odour and of bitter taste. It is easily soluble in water, gly

How much fats should be taken for management of obesity, How much Fats shou...

How much Fats should be taken for management of obesity? Fats, being a concentrated source of energy need to be restricted. Excess dietary fat promotes much more weight gain th

Postparturient haemoglobinuria, Post pa r turient haemoglobinuria It...

Post pa r turient haemoglobinuria It is also known as puerperal haemoglobinuria or nutritional haemoglobinurea and results in intravascular haemolysis, haemoglobinuria and a

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