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

Human genome initiative, Human Genome Initiative is the collective name fo...

Human Genome Initiative is the collective name for number of projects begun in 1986 by Department Of Energy (DOE) to  (1) create an ordered set of DNA segments from known chrom

How cholera is generally spread in humans, How cholera is generally spread ...

How cholera is generally spread in humans Associated Foods: Cholera is generally a disease spread by poor sanitation, resulting in contaminated water supplies. Sporadic cases o

How is energy transferred along a food chain?, How is energy transferred al...

How is energy transferred along a food chain? The energy flux beside a food chain is always unidirectional, from the producers to the decomposers.

Respiration, how do respiration take place in animal????

how do respiration take place in animal????

Explain the storage of vitamin a, Explain the Storage of vitamin A? The...

Explain the Storage of vitamin A? The primary organ for storage of vitamin A is the liver. Reserves are found in the stellate cells, as mentioned above. The average liver weigh

Explain water and electrolyte imbalance during kwashiorkor, Explain Water a...

Explain Water and electrolyte imbalance during kwashiorkor? The total body water and especially the extracellular fluid volume are increased in all forms of PEM. At the same ti

Observing where soil bacteria live, Observing where soil bacteria live ...

Observing where soil bacteria live Dig up a clover, alfalfa or soy-bean plant. Carefully increase all the soil from the roots and see if you can find the little white nodules o

Entropy, ENTROP Y - Transfer of energy takes place from high energy...

ENTROP Y - Transfer of energy takes place from high energy level to low energy level. Rudol f clausius gave this term. During it there is collision of particles, r

draw the cell at metaphase, Consider cell with a diploid chromosome number...

Consider cell with a diploid chromosome number of 4 (2n=4), one pair of the chromosomes is metacentric,the other is acrocentric. The metacentric is labeled a 1 a 1 while the acr

Somatic and germline gene therapy, All the cells present in the body contai...

All the cells present in the body contain genes and an approach targeted to modulate the expression of genes is known as gene therapy. This novel approach has emerged by the end of

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