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 might explain the pattern, A group of Ethiopians were assayed for CCR5...

A group of Ethiopians were assayed for CCR5-del32 deletion polymorphism. 223 were +/+, 64 were +/del32, and 6 were del32/del32. Are the observed data significantly different from H

Explain the steps of exercise, Explain the Steps of Exercise You have l...

Explain the Steps of Exercise You have learnt the steps of exercises in Block 3, Unit 1 of theory block. Let us review the steps. In aerobic exercises one has to under go fo

Berry - development of seed, Berry - Development of Seed In a berry mu...

Berry - Development of Seed In a berry much of the pericarp is fleshy or juicy. In tomato Lycopersicon esculentum even the placenta on which the seeds are borne is fleshy. The

Differance between rescue-capacity-building strategy, QUESTIONS: Write ...

QUESTIONS: Write an analysis of the Chapter Twelve, the concluding chapter in ROLL AWAY THE STONE. It will be worth UP TO 50 points if you do it well. Submit it through the "Ex

Explain the role of bones in human biology, Explain the role of Bones in hu...

Explain the role of Bones in human biology? Bone is covered by a tough outer membrane called the periosteum. The periosteum contains systems of capillaries that supply the bone

In which part of the digestive tube is water is absorbed, Q. In which part ...

Q. In which part of the digestive tube is water is chiefly absorbed? What about the mineral ions and vitamins? Most part of water, mineral and vitamins ions are absorbed by the

Explain barrier techniques - personal protective equipment, Q. Explain Barr...

Q. Explain Barrier Techniques - Personal Protective Equipment? The use of personal protective equipment (PPE) - clothing, masks, eyewear, and gloves - is part of routine dental

Phylogeny and evolution, While studying evolution, a student comes across a...

While studying evolution, a student comes across a cladogram that includes clades like amphibia, reptilia, aves, and mammalia. What must be the basal clade?

Define excretion of iron in human body, Define Excretion of Iron in Human B...

Define Excretion of Iron in Human Body? Our body has a limited capacity to excrete iron once it has been absorbed. Daily losses in adult man are between 0.9 to 1.05 mg. About 0

How cultural practices are effective at limiting disease, Give two cultural...

Give two cultural practices (not chemical) you could use to control black spot of rose. Based on your current knowledge of the disease triangle, why do you think these cultural pra

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