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

Characters of the hemichordata, Two typical characters of the Hemichordata ...

Two typical characters of the Hemichordata that can be observed and used to identify them are: i) Soft, worm-like or short unsegmented body. ii) Body is divided into a (i) pr

Explain the process of transposition of the great arteries, Transposition o...

Transposition of the Great Arteries with VSD and Left Ventricular Outflow Tract Obstruction: The presence of such a condition has to be surgically corrected title is differenc

Interaction of vitamin c with ascorbic acid and leucine, Define Interaction...

Define Interaction of vitamin c with Ascorbic acid and Leucine? Ascorbic acid : The biologically active form, ascorbate, is a cofactor or co-  substrate for eight isolated enz

Roles of abscisic acid, Roles of Abscisic Acid Abscisic acid (ABA) is ...

Roles of Abscisic Acid Abscisic acid (ABA) is a particularly interesting hormone with regard to the regulation of its own levels. Its levels rise and fall dramatically in seve

Hypocalcaemia, H y po c a l c a e m i a It is also known as ...

H y po c a l c a e m i a It is also known as milk fever or parturient paresis. The disease occurs due to imbalance in input and output of calcium and is characterize

How phytohormones help development of parthenocarpic fruits, How phytohormo...

How phytohormones help the development of parthenocarpic fruits? The Parthenocarpic fruits are those produced with no fecundation. Several plants naturally make parthenocarpic

The activated methyl cycle, S-Adenosyl   methionine   serve  as  a  donor  ...

S-Adenosyl   methionine   serve  as  a  donor  of  methyl  sets  in  numerous biological  reactions instance for in the formation  of creatine phosphate and in the synthesis of nuc

Into which classes are mollusc divided, Q Into which classes are mollusc di...

Q Into which classes are mollusc divided? What are some representing beings of each class? The phylum Mollusca is divided into five main classes: pelecypods, or bivalves (Pelec

Steroid and thyroid hormones, Steroid and Thyroid Hormones Cytoplasmic...

Steroid and Thyroid Hormones Cytoplasmic receptors for steroids are proteins with two subunits that bind to the steroid molecules. When both receptor sites are occupied by the

Explain the importance of vitamin E, Explain the Importance of Vitamin E ...

Explain the Importance of Vitamin E Vitamin E has a pronounced antioxidizing effect. Because of this property, vitamin E decreases the basic metabolism of the tissues or the ox

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