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

Neck examination of new born, Neck Inspect and palpate the neck for an...

Neck Inspect and palpate the neck for any mass, check if neck is short, and webbed which is indicative of Turner's syndrome. Palpate posteriorly along cervical spine; later

What are cerebrospinal and meninges fluid, Q. What are cerebrospinal and me...

Q. What are cerebrospinal and meninges fluid? Meninges are the membranes that protect and the enclose central nervous system (CNS). Cerebrospinal fluid is the fluid that separa

What are the major cells of the connective tissue proper, Q. What are the m...

Q. What are the major cells of the connective tissue proper? What is the name given to the intercellular material that surrounds these cells? The major cells of the connective

Is herbivorism a form of predatism, Q. Is herbivorism a form of predatism? ...

Q. Is herbivorism a form of predatism? The Herbivorism is a form of predatism in which first order consumers feed from producers (plants or algae). For instance, fruits and bir

Dna vs protein, Describe the difference between dna and protein. (structura...

Describe the difference between dna and protein. (structural unit, linkage bond, primary and spatial structure)

Polypeptide chains of hemoglobin, Q. In sickle cell anemia, a hereditary di...

Q. In sickle cell anemia, a hereditary disease, there is replacement of one amino acid by another in one of the four polypeptide chains of hemoglobin. In this case are all of the s

What are the typical features of mammals, What are the typical features of ...

What are the typical features of mammals? The typical features of mammals are: body (more or less) covered with hair; presence of the diaphragm muscle (that divides the thorax

The glomerular filtrate in comparison to the blood, What is the main transf...

What is the main transformation presented by the glomerular filtrate in comparison to the blood? Glomerular filtrate is the name given to the plasma after it has passed the glo

Explain the properties of gum tragacanth, Explain the Properties of Gum tra...

Explain the Properties of Gum tragacanth Gum tragacanth swells in water to give thick  viscosity dispersions or pastes similar in texture to soft gels. The viscosity shows a sh

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