Corpus luteum

	WikiDoc Resources for Corpus luteum
Articles
Most recent articles on Corpus luteum Most cited articles on Corpus luteum Review articles on Corpus luteum Articles on Corpus luteum in N Eng J Med, Lancet, BMJ
Media
Powerpoint slides on Corpus luteum Images of Corpus luteum Photos of Corpus luteum Podcasts & MP3s on Corpus luteum Videos on Corpus luteum
Evidence Based Medicine
Cochrane Collaboration on Corpus luteum Bandolier on Corpus luteum TRIP on Corpus luteum
Clinical Trials
Ongoing Trials on Corpus luteum at Clinical Trials.gov Trial results on Corpus luteum Clinical Trials on Corpus luteum at Google
Guidelines / Policies / Govt
US National Guidelines Clearinghouse on Corpus luteum NICE Guidance on Corpus luteum NHS PRODIGY Guidance FDA on Corpus luteum CDC on Corpus luteum
Books
Books on Corpus luteum
News
Corpus luteum in the news Be alerted to news on Corpus luteum News trends on Corpus luteum
Commentary
Blogs on Corpus luteum
Definitions
Definitions of Corpus luteum
Patient Resources / Community
Patient resources on Corpus luteum Discussion groups on Corpus luteum Patient Handouts on Corpus luteum Directions to Hospitals Treating Corpus luteum Risk calculators and risk factors for Corpus luteum
Healthcare Provider Resources
Symptoms of Corpus luteum Causes & Risk Factors for Corpus luteum Diagnostic studies for Corpus luteum Treatment of Corpus luteum
Continuing Medical Education (CME)
CME Programs on Corpus luteum
International
Corpus luteum en Espanol Corpus luteum en Francais
Business
Corpus luteum in the Marketplace Patents on Corpus luteum
Experimental / Informatics
List of terms related to Corpus luteum

Template:Infobox Anatomy

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

The corpus luteum (Latin for "yellow body") (plural corpora lutea) is a temporary endocrine structure in mammals, involved in the production of the progestogens which are needed for the maintenance of a pregnancy.

Development and structure

The corpus luteum develops from an ovarian follicle during the luteal phase of the menstrual cycle or estrous cycle, following the release of a mature ovum (egg) from the follicle during ovulation. The follicle first forms a corpus hemorrhagicum before it becomes a corpus luteum, but the term simply refers to the visible collection of blood left after rupture of the follicle, and has no functional significance. While the oocyte (later the zygote) traverses the Fallopian tube into the uterus, the corpus luteum remains in the ovary.

The corpus luteum is typically very large relative to the size of the ovary; in humans, the size of the structure ranges from under 2 cm to 6 cm in diameter. ^[1]

Its cells develop from the follicular cells surrounding the ovarian follicle:

Source	Becomes	Secretion
The granulosa cells	the inner granulosa lutein layer	progesterone, estrogen
Theca cells	the outer theca lutein layer	progesterone, androgens

Function

It is essential for establishing and maintaining pregnancy in females.

In the ovary, the corpus luteum secretes estrogens and progesterone, which are steroid hormones responsible for the thickening of the endometrium and its development and maintenance, respectively.

When egg is not fertilized

If the egg is not fertilized, the corpus luteum stops secreting progesterone and decays (after approximately 14 days in humans). It then degenerates into a corpus albicans, which is a mass of fibrous scar tissue.

The uterine lining sloughs off without progesterone and is expelled through the vagina (in humans and some great apes, which go through a menstrual cycle). In an estrus cycle the lining degenerates back to normal size.

When egg is fertilized

If fertilized, however, the embryo secretes the hormone human chorionic gonadotropin (hCG) or a similar hormone in other species.

This hormone signals the corpus luteum to continue progesterone secretion, thereby maintaining the thick lining (endometrium) of the uterus, and providing an area rich in blood vessels in which the zygote(s) can develop. From this point on, the corpus luteum is called the corpus luteum graviditatis.

The introduction of the hormone prostaglandin at this point causes the degeneration of the corpus luteum and the abortion of the fetus. However, in placental animals such as humans the placenta eventually takes over progesterone production and the corpus luteum degrades into a corpus albicans without embryo/fetus loss.