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

Gene, Gene  is the fundamental physical and functional unit of the heredity...

Gene  is the fundamental physical and functional unit of the heredity (generally DNA, Some of the organisms have RNA a gene). A gene is an ordered series of nucleotides located in

Excretion in amoeba, EXCRETIO N IN AMOEBA - NH 3  is excreted out t...

EXCRETIO N IN AMOEBA - NH 3  is excreted out through plasmalemma. Osmoregulation takes place by contractile vacoule, generally one, towards posterior end, contractile in

Disorder of skeleton and joints, DISORDER OF SKELETON AND JOINTS - 1 ...

DISORDER OF SKELETON AND JOINTS - 1 .      Sprain - It involves a stretching or tearing of tendons or ligaments. 2.      Arthritis - It is infalmation of joints.

Membrane perforation of sinus graft surgery, Membrane Perforation of sinus ...

Membrane Perforation of sinus graft surgery it is the most common complication during the sinus graft surgery resulting from the scoring of lateral access window for surgery an

Properties of stem cells-pulp tissue revascularization, Properties of Stem ...

Properties of Stem Cells Stem cells are defined by having 3 major properties: 1) They are capable of self-renewal.  2) They divide, some daughter cells give rise to cells

Explain about gastric ulcers, Q. Explain about Gastric ulcers? Gastric ...

Q. Explain about Gastric ulcers? Gastric ulcers occur in the lesser curvature of the antrum of stomach. A gastric ulcer appears to be caused by reflux of bile and factors that

Explain selective breeding methods, Explains how selective breeding methods...

Explains how selective breeding methods could be used to produce a population of cats with the short legs. Selective breeding E1: bases explanation on the assumption t

Nutrition education for prevention of vitamin a deficiency, Define Nutritio...

Define Nutrition Education for prevention of vitamin a deficiency? Ignorance, you may recall studying earlier, is an important determinant of vitamin A deficiency. There is, th

How different are animal cells from plant cells, How different are animal c...

How different are animal cells from plant cells? Whereas plant cells are eukaryotic, autotrophic, photosynthetic and have chloroplasts and cell wall, the animal cells are eukar

Systems of human body, Systems of Human Body Many organs work in a coo...

Systems of Human Body Many organs work in a coordinated'manner to form a system. For example in our-body the nose, the trachea and the lungs form the respiratory system. Table

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