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

Define etiology and clinical features of alzheimer''s disease, Define the E...

Define the Etiology and Clinical Features of alzheimer's disease? The probable risk factors include a genetic basis, head injury, low education level, Down syndrome and mother

Explain radiation sterilization, Explain radiation sterilization Variou...

Explain radiation sterilization Various studies have been conducted which show the effect of processing on vitamins especially, thiamine. In one study, which compared the effec

Asphyxia, buffalo can be dies due ashyxia

buffalo can be dies due ashyxia

Ureotelism - excretion, Normal 0 false false false EN-I...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Sulphur cycle - nutrient cycles, Sulphur Cycle - Nutrient Cycles The s...

Sulphur Cycle - Nutrient Cycles The sulphur cycle is mostly sedimentary except for a short gaseous phase. The large reservoir of sulphur is in the soil and sediment where it i

Reproduction, REPRODUCTIO N - It is not only production of new ones...

REPRODUCTIO N - It is not only production of new ones to increases its number but a means for the survival of a population on earth. Main aim is "survival and continuati

Can you define p-waves, Q. Can you define P-Waves? Changes in P-wave mo...

Q. Can you define P-Waves? Changes in P-wave morphology have been well described in resting tracings and are very useful in identifying right and left sided hemodynamic alterat

Prophase of karyokinesis, 1. This is very prolonged phase, and differs from...

1. This is very prolonged phase, and differs from the prophase of mitosis, because in this Chromosomes behave as homologous pairs. 2. Each diploid cell has two chromosomes of ea

How vitamin e provide synthesis of enzymes and proteins, How Vitamin E prov...

How Vitamin E provide Synthesis of enzymes and proteins? 1) Synthesis of enzymes and proteins: It serves as a co-repressor in the synthesis of certain enzymes and plays a speci

State the term - antecedent and consequence control, Antecedent and consequ...

Antecedent and consequence control Therapy and consultation cannot be effective unless the behaviours to be changed are understood within a particular context. The process of u

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