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
What is the difference between the alpha helix and the beta-sheet protein conformations? Ans) Alpha helix and beta-sheet conformations are the two major types of secondary struc

In the more highly developed animals, like humans this gas is used to regulate activity of the heart, blood vessels and respiratory system. WORKING MUSCLES PRODUCE A LARGE AMOUNT O

examples of gametes

What is the quaternary structure of a protein? Do all proteins have quaternary structure? The quaternary protein structure is the spatial conformation because of interactions b

List various criteria for optimum health and satisfactory health according to implant quality scale The criteria for Optimum health according to Implant quality scale are: -

Soil pH and Nutrient Availability Soil pH is the most important factor which governs the availability of nutrients in soil. All the nutrients are absorbed by plants in their io

Skeleton - Animal Kingdom You all know that the skeleton forms the framework of the body of different organisms in the animal kingdom. Besides giving shape to the animal, it a

biological significant of a skeleton

Drugs for hepatitis B Chronic HBV infection is currently treated with interferon alfa, lamivudine or adefovir. Lamivudine is much better tolerated than interferon and much les

1. DNA damaga can be spontaneous or can be 'Induced by external agents a. What are 'spontaneous' mutations? Give examples of causes of spontaneous mutations and the kinds od DNA