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

Inter phase - cell cycle, The period of life cycle of cell (cell cycle) bet...

The period of life cycle of cell (cell cycle) between two consecutive divisions is termed as the Interphase or misleading called resting phase. It is a period

Ross operation-surgical techniques, Ross Operation :  In this technic...

Ross Operation :  In this technically demanding operation, the aortic valve is replaced by patient's own pulmonary valve (autograft) and a pulmonary or aortic allograft (homo

Portal circulation, POR T AL CIRCULATION When a vein branches into se...

POR T AL CIRCULATION When a vein branches into set of capillary to distribute blood in some parts, such venous circulation is called portal system. Three types of portal syst

Cessation of spontaneous body functions, A person is declared to be dead up...

A person is declared to be dead upon the irreversible cessation of spontaneous body functions; brain activity, or blood circulation and respiration. However,only about 1% of a pers

Thermal properties-specific heat-water properties, Thermal Properties ...

Thermal Properties The range of temperature variatidn in the aquatic environment is smaller in comparison to air. This means the rate of change of temperature is slower in the

Enteric infectious viral disease, Match each item in Column A with the corr...

Match each item in Column A with the corresponding item in Column B regarding infectious diseases Column A Column B a. Pulmonary tuberculosis i. Enteric infectious protozoan diseas

Do you know how ketoacidosis develops, Q. Do you know how ketoacidosis deve...

Q. Do you know how ketoacidosis develops? The chain of reaction begins with insufficient insulin to meet the needs of the body. Several factors then work together. These inclu

Interdependance, Give an example of how two organisms are interdependent.

Give an example of how two organisms are interdependent.

Define spiral cleavage in brief., Define Spiral cleavage in brief. Patt...

Define Spiral cleavage in brief. Pattern of cell division in the developing embryo where products of the cell divisions shift by rotating either counterclockwise or clockwise s

Describe the factors of maintenance of implants, What are the special consi...

What are the special considerations required to be taken in maintenance of implants? The procedures for maintenance of patients with implants are similar to those with natural

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