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

Glucose rehydration therapy, The movement  of Na + and glucose  from the l...

The movement  of Na + and glucose  from the lumen  of the intestine  across  the epithelial  cell to the blood  sets up a dissimilarity  in osmotic  pressure  across  the cell. As

Pporifera, write the general account of porifera

write the general account of porifera

Respiration, define respiration in diffrent types of animals

define respiration in diffrent types of animals

Test cross, TEST CROSS Crossing of F hybrid with its homozygous recessi...

TEST CROSS Crossing of F hybrid with its homozygous recessive parent is called test cross and the progeny of test cross is called test cross progeny. A .      Monohybrid Te

Explain right atrial enlargement, Q. Explain Right Atrial Enlargement ? ...

Q. Explain Right Atrial Enlargement ? The right atrium (RA) is a globular chamber, forming the right heart border on the PA view. On the PA view, the border of the enlarged RA

Explain acylglycerols, Explain acylglycerols The most abundant class of...

Explain acylglycerols The most abundant class of food lipids is the acylglycerols, also known as glycerol esters of fatty acids, which dominate the composition of depot fats in

Define polysaccharides (dp: > 9) - carbohydrates, Define Polysaccharides (D...

Define Polysaccharides (DP: > 9) - carbohydrates? Polysaccharides are high molecular weight polymers of monosaccharide units formed by glycosidic bonding. They may be long unbr

Define about the iron deficiency anaemia (ida), Define about the Iron Defic...

Define about the Iron Deficiency Anaemia (IDA)? Iron deficiency anaemia (IDA) is the most common micronutrient deficiency in the world, particularly in the developing countries

Respiratory care on admission of patient, Respiratory Care on Admission (Fi...

Respiratory Care on Admission (First two hours) Patient is incubated and ventilator-dependent.  Monitor blood gases hourly and take corrective action immediately.

The osmolarity of the rbcs and plasma after equilibration, Ed Rivers, a 3rd...

Ed Rivers, a 3rd year medical student, was alone in the hospital ER one night. It was unusually quiet that night, and the resident was getting some much needed sleep. A patient, Mr

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