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 steroid hormones , Cholesterol is the precursor of the five major...

Cholesterol is the precursor of the five major classes of steroid hormones.The synthesis of steroid hormones is initiated by the removal of a six-carbon unit  from  carbon  20  of

Illustrate about sarcoplasmic reticulum membranes, An increase in the calci...

An increase in the calcium conductance of all sarcoplasmic reticulum membranes of a skeletal muscle with no external forces on it leads to A. Increased binding of calcium ions

Measures of evenness, Measures of Evenness The maximum Shannon-Wiener i...

Measures of Evenness The maximum Shannon-Wiener index for a given number of species can be calculated as: The minimum Shannon-Wiener index for a given data set can be c

What is the resistance of its circuitry, A flashlight with a 6-volt bulb dr...

A flashlight with a 6-volt bulb draws 2 amps from its batteries. What is the resistance of its circuitry?

Final atp count in both prokaryotes and eukaryotes, Degrade a monoglyceride...

Degrade a monoglyceride that has an 18-carbon fatty acid attached to it by Ester bonds. You will have to degrade the glycerol component followed by the fatty acid in presence of O2

Determine the nature and degree of abnormality, Determine the Nature and De...

Determine the Nature and Degree of Abnormality The nature and degree of abnormality will effect normal neural growth and maturational outcome. For example, in an adult damage t

Respiration, how energy enters and then flows through a biological system

how energy enters and then flows through a biological system

Air pollution, It is defined as the presence of chemicals and particulate i...

It is defined as the presence of chemicals and particulate in the atmosphere in quantities and pollution that are harmful to human health and environment. It occurs when the concen

Define the nutritional and functional role of nickel, Minerals :-Nickel  ...

Minerals :-Nickel  Food Source      Plant foods  Nutritional Functional role Essential nutrient: Deficiency in humans unknown. Catalyst: hydrogenation in

Blunt or non-penetrating injury, Blunt or Non-penetrating Injury When ...

Blunt or Non-penetrating Injury When body is struck by a blunt object such as steering wheel or blows to chest with blunt object. External injury may appear minor but the

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