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

Osmoregulation in animals, Osmoregulation in Animals Osmoregulation as...

Osmoregulation in Animals Osmoregulation associates to the regulation of water and ionic content of the body of non-chordate metazoans. These might be osmoconformers / osmoreg

Factor influencing lipid oxidation - temperature, Factors affecting lipid o...

Factors affecting lipid oxidation Temperature In general, the rate of oxidation increases as the temperature is increased. Temperature also influences the relation betw

Cohesiveness and surface tension-properties of water, Cohesiveness and Surf...

Cohesiveness and Surface Tension Water flows freely, yet water molecules do not break apart. They cling together particularly to polar surfaces. Therefore, water can fill a tub

Morphological changes, Morphological changes Aquatic plants produce di...

Morphological changes Aquatic plants produce different kinds of leaves and produce aerenchyma (tissues with air gaps) where there be a need to do so. Also, a thick cuticle on

Explain the types of double beam systems, Explain the types of double beam ...

Explain the types of double beam systems? Following are types of double beam systems: a) Dual beam in space type b) Dual beam in time type In type (a) separate detecto

Difference between open system and closed system, DIFFERENCE BETWEEN OPEN S...

DIFFERENCE BETWEEN OPEN SYSTEM AND CLOSED SYSTEM - S .No. C h arac t er O p en system C losed system

What is the genetic disease in which this factor is absent, What is factor ...

What is factor VIII? What is the genetic disease in which this factor is absent? Factor VIII has the function of activating factor X that in its turn is essential for the trans

Glycogenesis, Glycogenesis :   This  is an anabolic process  in which  gluc...

Glycogenesis :   This  is an anabolic process  in which  glucose is polymerized  into glycogen by the   sequence of  reactions.  Since glycogenesis occur  in all  body  cells .but

Name a few foods which are best blanched, Name a few foods which are best b...

Name a few foods which are best blanched? Yes, green beans, carrots, okra, turnip and cabbage should always be blanched. On the other hand, blanching is not needed for onions,

Psychotropic drugs, Psychotropic Drugs - Act on brain and effect its no...

Psychotropic Drugs - Act on brain and effect its normal functioning slow down and interphere in the functioning of the nervous system. These drugs alter behaviour, consciosn

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