Phases of menstrual cycle - reproduction, Biology

Phases of Menstrual Cycle - Reproduction

Four phases of the menstrual cycle are usually distinguished: the menstrual, proliferative (follicular), ovulatory and progestational (luteal). The proliferative phase is conditioned by estrogen and extends from the end of menstruation to ovulation. Ovulation occurs near the middle of the cycle. At the end of menstrual disintegration, the endometrium is thin and poorly vascularised and only the basal parts of the endometrial glands remain. The endometrium thickens as the estrogen titers rise and the glandular and vascular patterns are restored. No conspicuous changes occur in the endometrium during the ovulatory process.

Cyclic variation in the body temperature of the human female correlate with menstrual changes. A distinct rise in basal body temperature occurs at ovulation and remains high until the onset of the next menstrual period. The changing titers of hormones during the menstrual cycle apparently account for the temperature fluctuations. During the progestational phase the uterus is under the influence of both estrogens and progestogens and the endometrium differentiates into a tissue that can fulfil the requirements of an embryo ready to implant. The progestational endometrium normally requires both estrogens and progesterone. it is the only type of structure in which blastocyst can readily implant and develop normally. If implantation has not occurred the corpus luteum diminishes in function and degenerative changes are observable in the endometrium. With menstruation the outer portion of the endometrium is lost and there is bleeding into the uterine cavity.

Posted Date: 1/16/2013 11:44:12 PM | Location : United States







Related Discussions:- Phases of menstrual cycle - reproduction, Assignment Help, Ask Question on Phases of menstrual cycle - reproduction, Get Answer, Expert's Help, Phases of menstrual cycle - reproduction Discussions

Write discussion on Phases of menstrual cycle - reproduction
Your posts are moderated
Related Questions
Arterial Conduits LIMA UMA: anastomosis side-t-side with diaganal8 end-lo-sode with LAD Figure: Arterial conduits Internal Mamnrary Artery (IMA)

MCNAUGHTON'S CASE AND LAW: In 1843, McNaughton shot and  killed Sir Robert Peel's secretary Edward -Drymmond.  It was  shown  that McNaughton suffered from a number of  delusi

Lakes - Lentic Ecosystems Most lakes occur in regions which have recently been subjected to geological changes; say within the past 20,000 years. However, a few lakes, such a

Q In which environments bacteria live? Bacteria can be found in a variety of environments throughout the planet. There are bacteria in the air, on the surface, in fresh water,

Antimicrobial prophylaxis Antimicrobial prophylaxis is generally not indicated for cardiac catheterization, varicose vein surgery, most dermatologic and plastic surgery, arteri

Explain the Human Milk Composition and Infant Growth and Development? This sub-section deals with composition of human milk, compares human milk with cow's milk and why human m

Q. What is the significance of the uterine glycogen- producing glands? The uterine glands produce glycogen that able to degrade into glucose to nourish the embryo before the co

Human Impact on Nitrogen Cycle Human activities are profoundly affecting the cycling of nitrogen in nature. Over 30 x 10 6 metric tons/yr. of N 2 is fixed in the commercial

Q. Whcih group of individual animals and plants called Species? A group of individual plants and animals that are fundamentally alike is treated as a ,species. Species is a par

Q. The vascular lesions caused by leeches upon the blood vessels of their host cause blood naturally to coagulate. How does the leech solve this problem since it could be expected