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
Explain Flucytosine Flucytosine (Ancobon) - Potentially lethal, dose-related bone mar- row toxicity, colitis and rapid development of resistance when used alone limit the use o

respiratory system in amphibains

Q. How do sponges try to protect themselves against harm from the environment? Is that method rudimentary or efficient? Sponges can close their pores to avoid the entrance of w

Which of the following serves as an actuating signal, or as part of an actuating signal, in a negative feedback system? A. Action potentials in diaphragm skeletal muscle fibers

An  osteoclast  is a type of bone cell that absorbs bone tissue by removing its mineralized matrix and breaking up the  organic bone. This process is known as bone resorption

Why is sex-linked inheritance an example of nonmendelian inheritance? The Sex-linked inheritance is a kind of nonmendelian inheritance because it opposes Mendel's first law, wh

explain anatomy of bacteria

Define Transverse section of body of male Ascaris? 1. Body wall consists of the following: (a) Cuticle is the outermost layer. It is a thick, tough, elastic membrane

What is Class Chondrichthyes? Class Chondrichthyes takes its name from two Greek words. "Chondros"; means cartilage, and "ichthys"; refers to fish, therefore the name "cartilag

Ask question importance of genetics in human life #Minimum 100 words accepted#