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

Reproduction., in oogenesis only on functional egg cell is normally formed ...

in oogenesis only on functional egg cell is normally formed from primary oocyte. Briefly explain

Simple lipids, SIMPLE  LIPIDS They are lipids formed of fatty acids an...

SIMPLE  LIPIDS They are lipids formed of fatty acids and alcohol without any additional group. e.g. fats or true fats,wax,cutin, suberin. Simple lipids are mainly of 2 types

What is the role of the ozone layer for living beings, What is the role of ...

What is the role of the ozone layer for living beings? Ozone, O3, is a gas of the atmosphere that filters ultraviolet radiation from the sun disallowing most of that radiation

Is nitrogen is important plant nutrients, Is nitrogen is important plant nu...

Is nitrogen is important plant nutrients Nitrogen is an important plant nutrient which is assimilated by most of the plants as nitrate and ammonium ions. Organic matter is the

Explain solubility and physical properties of proteins, Solubility and phys...

Solubility and physical properties of protiens Simple proteins Conjugated proteins Derived proteins

Functions of lysosomes, FUNCTIONS (1 )      Intracellular digestion -...

FUNCTIONS (1 )      Intracellular digestion - Individual cells may obtain food through phagocytosis. The same is digested with the help of lysosomes. It is of two types:-

Life style modification in management of diabetes mellitus, Life style modi...

Life style modification in the management of diabetes mellitus All of us have our own way of living. It becomes a routine when we do things in the same way. But when one falls

Explain the use and care of microscope, Explain the Use and Care of Microsc...

Explain the Use and Care of Microscope? Proper care and maintenance of microscope is needed. Following points should be kept in mind while handling the microscope: (i) Instr

Explain the term - migraine, Explain the term - Migraine Perhaps the mo...

Explain the term - Migraine Perhaps the most common neurological disorder, migraine afflicts some 5% to 20% of the population at some time in their lives. The World Federation

Congenital discrete subvalver stenosis, Congenital Discrete Subvalver Steno...

Congenital Discrete Subvalver Stenosis : The abstraction could be fibrous or fibro muscular. It could be anywhere from just below the aortic cusps upto the level of the free edge

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