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

Explain what is organismal ecology, Explain what is Organismal Ecology? ...

Explain what is Organismal Ecology? Ecology at the Level of Individuals: We define ecology as the study of the relationships between organisms and the relationships between o

Explain valacyclovir, Valacyclovir (Valtrex) - Valacyclovir is an L-val...

Valacyclovir (Valtrex) - Valacyclovir is an L-valyl ester of acyclovir that is metabolized to acyclovir after oral administration, resultingin higher serum concentrations than

What is an accommodation, What is an accommodation? Accommodation is th...

What is an accommodation? Accommodation is the ability of the eye to focus on an object situated at variable distances from the eye. Like a camera, even the eye requires to cha

Define the parathryroid hormone receptors, Which of the following serves as...

Which of the following serves as a sensor, or as part of a sensor, that functions only in a negative feedback system and not in a positive feedback system? A. CaSRs (Calcium-Se

Preparation of the standard curve for haemoglobin, Preparation of the stand...

Preparation of the standard curve for haemoglobin? Label 6 clean dry rest tubes and label them as S1 -S6 Add 5 ml of Drabkin's solution to test tube numbers S2 - S6

Recurrent type, Recurrent Type In this type, euspory (seen in normal ...

Recurrent Type In this type, euspory (seen in normal cases) is replaced by aneuspory (Diplospory) because of irregular meiosis. When the spore mother ceIl functions directly

Branchiostoma, What is the feeding habitat of branchiostoma?

What is the feeding habitat of branchiostoma?

Explain three parts of homogenate, Differential centrifugation divides cell...

Differential centrifugation divides cellular components based on the differences in their size and / or density. A tissue sample was homogenized and three parts (aliquots) of this

Protein x has an absorptivity of 0.4 ml, Protein X has an absorptivity of 0...

Protein X has an absorptivity of 0.4 mL . mg -1 . cm-1 at 280nm. What is the ab sorbance at 280 nm of a 2.0 mg. mL-1 solutionof protein X ? (Assume the light path is 1 cm).

Explain kidney transplant, Consider the following four statements (a - d) r...

Consider the following four statements (a - d) regarding kidney transplant and select the two correct ones out of these. 1. Even if a kidney transplant is proper the recipient m

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