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

Non migrainous vascular headaches, Non Migrainous Vascular Headaches Th...

Non Migrainous Vascular Headaches This headache associated with dilation of the cranial arteries and can be induced by a wide variety of diseases and conditions. The most commo

Biosphere, Biosphere Biosphere is that part of the earth where life can...

Biosphere Biosphere is that part of the earth where life can exist. It is a narfqy layer around the surface of the earth. If you visualise the earth to be the size of an apple

Timber, what is cup shake?

what is cup shake?

Where in the plants is a large amount of iaa found, Where in the plants is ...

Where in the plants is a large amount of IAA found? The Auxins are produced and found in large amount in the apical buds of the shoots and stem and in the young leaves.

Determine the muscular-skeletal system, Determine the Muscular-Skeletal Sys...

Determine the Muscular-Skeletal System It is known we all do movement and these take place by movement of muscles in coordination with the skeletal system. In human body muscle

Gene targeting in somatic cells, Gene targeting in somatic cells: Since t...

Gene targeting in somatic cells: Since the pioneering work with sheep at Roslin cloning by nuclear transfer has now been exemplified in a number of other livestock species includ

Explain the terminology niche, Explain the terminology Niche ? The term...

Explain the terminology Niche ? The term niche is used often in ecology, and its meaning has been defined and interpreted in various ways over the years. An organisms niche has

Atelectasis and pneumonia - complications of cardiac surgery, Atelectasis a...

Atelectasis and Pneumonia Signs and symptoms are LV failure, hypovolemia, hypervolemia or renal vasoconstriction. Decreased breath sounds, poor ABG and poor cough reflex

Types of transport process in sieve tubes, Types of Transport Process in Si...

Types of Transport Process in Sieve Tubes The metabolites of all the mesophyll cells around the sieve elements join in a common pool to load via the surrounding transfer cells

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