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 sex-linked traits in genetics, What is Sex-linked Traits in genetic...

What is Sex-linked Traits in genetics? The X-chromosomes carry genes for traits other than sex characteristics. Morgan discovered these sex-linked traits while observing the in

Properties of fatty acid, A fatty acid having of a hydrocarbon chain and a ...

A fatty acid having of a hydrocarbon chain and a terminal carboxylic acid group that is shown in the figure.  Most  fatty  acids  are  in  biology  have  an  even  number  of carbo

Difference between "a" and "i" bands, DIFFERENCE S BETWEEN "A" AND "I" BAN...

DIFFERENCE S BETWEEN "A" AND "I" BANDS     A-Ban d (Anisotropic band)   I-Ban d (Isotropic band) 1. It

Define etiology and clinical features of alzheimer''s disease, Define the E...

Define the Etiology and Clinical Features of alzheimer's disease? The probable risk factors include a genetic basis, head injury, low education level, Down syndrome and mother

Define sweetness as a function of sugar, Define Sweetness as a Function of ...

Define Sweetness as a Function of Sugar? Sweetness is the most recognized functional property of sweeteners. Our preference for sweetness, regarded as innate, is apparent soon

Indication of exchange transfusion, Indication of Exchange Transfusion ...

Indication of Exchange Transfusion i) Early exchange transfusion is indicated in the presence of hydrops and is often indicated by a history of previously severely aff

Explain factors that alter the speed of enzymatic recations, What are the m...

What are the main factors that alter the speed of enzymatic reactions? The major factors that change the speed of enzymatic reactions are temperature, pH and substrate concentr

Use of sulphur dioxide and sulphites in microorganisms, Q. Use of Sulphur d...

Q. Use of Sulphur dioxide and sulphites in microorganisms? Sulphur dioxide as a preservative in wine preparation has been in use since ancient times. It is also used in other f

Protozoa, advantages and disadvantages of protozoa

advantages and disadvantages of protozoa

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