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

Triple fusion, Triple Fusion The fusion process between the other male...

Triple Fusion The fusion process between the other male gamete and the secondary nucleus follows the same pattern as syngamy. In most plants, the polar nuclei are only partial

Difference between phanerogamic and cryptogamic plants, Q. What is the diff...

Q. What is the difference between phanerogamic and cryptogamic plants? Cryptogamic (hidden sex organs) plants are those that do not present seeds or flowers. They comprise the

Coevolution of prey-predators, Predation is a process by which one organism...

Predation is a process by which one organism (predator) eats another organism (prey). If the prey population is abundant, the predator population also becomes abundant. If the pred

Conditions requiring rapid treatment of hypertension, List of Conditions Re...

List of Conditions Requiring Rapid Treatment of Hypertension 1) Cardiac: • Acute aortic dissection • Acute left ventricular failure • Acute or evolving myocardial i

Excretory system of animals and human urinary system, steps in urine format...

steps in urine formation and the organs/tissues involve in such process?

Management of pulmonary edema, Pulmonary edema is life-threatening conditio...

Pulmonary edema is life-threatening condition and therefore, treated as a medical emergency. As is the case with chronic stable heart failure, identification and correction of any

Insulin and its functions, People with Type 1 DM produce no insulin. People...

People with Type 1 DM produce no insulin. People with Type 2 DM do not always produce enough insulin. Insulin is used medically to treat some forms of diabetes mellitus. Patients w

What are passive and active immunization, What are passive and active immun...

What are passive and active immunization? According to the duration of the protection how do these types of immunization differ? Active immunization is that in which an antigen

Explain the bunsen burner, Explain the Bunsen Burner? It is a type of g...

Explain the Bunsen Burner? It is a type of gas burner that gives very hot flame by allowing air to enter at the base and mix with the gas. It is used - (a) For sterilizing i

Emulsion preparation, Em u l sio n preparation Frozen deboned meat,...

Em u l sio n preparation Frozen deboned meat, fat and by-products are tempered at 0° to 4° C for 12to 15 hr and cut into pieces and coarse minced by passing through 8, 10 o

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