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 are the classes of lipoproteins in the blood, Q. What are the classes ...

Q. What are the classes of lipoproteins in the blood? Blood lipids (cholesterol, triglycerides and phospholipids) being insoluble in blood need a ship to travel in our body; it

Pollenkitt - pollen wall, Pollenkitt - Pollen Wall The lipoidal layer ...

Pollenkitt - Pollen Wall The lipoidal layer found on the outside of the mature pollen grains of many insect pollinated species is known as the pollenkitt. In addition to lipid

Determine teh term - magnesium, Determine teh term - Magnesium  Magnes...

Determine teh term - Magnesium  Magnesium helps in translocation of carbohydrates and regulates the uptake of other nutrients, presumably by helping in the formation of phosph

Why should posterior wall preffered during surgery, Why should Posterior wa...

Why should Posterior wall preffered during surgery Posterior wall should not be perforated during surgery. This limits bleeding from the pterygoid plexus or branches of the max

What is signifying by suction force of the plant cell, Q. What is signifyin...

Q. What is signifying by suction force of the plant cell? Does the suction force facilitate or make difficult the entry of water into the cell? The suction force (SF) is the os

Choice of transgenic animal, C h oice of transgenic animal First and ...

C h oice of transgenic animal First and foremost is the selection of animal species in which gene of interest is to be transferred. Whatever is the goal of production of tran

Describe in detail about the chlorophyll molecule, Describe in detail about...

Describe in detail about the chlorophyll molecule Each chlorophyll molecule contains magnesium ion, there could be no green plants without magnesium. As magnesium is present in

Precaution for determination of haemoglobin content in blood, Define Precau...

Define Precautions for Determination of Haemoglobin Content in Blood 1. Potassium cyanide is highly toxic and hence drabkin's solution should not be pippeted by mouth. 2. Dr

Describe the tailored to the individual patient, Describe the tailored to t...

Describe the tailored to the individual patient? Patent ductus arteriosus (PDA) interruption (surgical or transcatheter intervention): It is a curative procedure. Atrial

Why are vaccines made of the own disease agent, Why are vaccines made of th...

Why are vaccines made of the own disease agent or of fragments of it? The goal of vaccines is to artificially persuade a specific primary immune response (and the consequent fo

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