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

Explain short term complications, Q. Explain Short term complications? ...

Q. Explain Short term complications? Short term complications may arise due to GERD which may in turn increase the frequency or severity of this disease. One of the complicatio

Evaluation of health services, CONCEPT AND MEANING OF EVALUATION: Eval...

CONCEPT AND MEANING OF EVALUATION: Evaluation of programmes is critical for measuring various community health services The ultimate reasons for doing evaluation is to ensure

Fundamental cardiac unit, The fundamental contractile unit is the sarcomere...

The fundamental contractile unit is the sarcomere. Each muscle cell apart from the nucleus, mitochondria and other structures contains parallel fibrils. Sarcomere is a subunit of t

Explain about chronic gastritis, Q. Explain about Chronic Gastritis? It...

Q. Explain about Chronic Gastritis? It precedes development of organic gastric lesion, or tissue damage. Recurrent inflammation leads to changes in enzyme activity of gastric m

What is lipid-lowering trial, Q. What is Lipid-lowering Trial? Aggressi...

Q. What is Lipid-lowering Trial? Aggressive lipid-lowering drug treatment of persons at various risk levels reduces Coronary Artery Disease morbidity and mortality rates and in

Nature of disease, Q. Nature of disease? Education is very important fo...

Q. Nature of disease? Education is very important for diabetics because it is a lifelong disorder. In order to enable the patient to lead a healthy and a good quality Life free

Epidemiological association between hemophilia and HIV, What is the epidemi...

What is the epidemiological association between hemophilia and HIV infection? As hemophilic patients need frequent transfusions of clotting factors (VIII or IX) they are more s

Microorganisms on basis of oxygen requirement for growth, Q. Microorganisms...

Q. Microorganisms on basis of oxygen requirement for growth? On basis of oxygen requirement for growth: - Obligate Aerobes: Require oxygen for growth and multiplication e.g

Explain about myocardial infarction, Q. Explain about Myocardial Infarction...

Q. Explain about Myocardial Infarction? It is an initial acute phase of cardiovascular disease caused by the blockage of a coronary artery supplying blood to the. Heart shows t

What is cilia and flagella, What is Cilia and Flagella? The surfaces of...

What is Cilia and Flagella? The surfaces of many eukaryotic cells bear cilia or flagella, built from specialized microtubules. Cilia are tiny brushlike hairs, and flagella are

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