Table of Contents
Introduction
A uterine fibroid (known medically as a leiomyoma or myoma) is a noncancerous (benign) growth of smooth muscle and connective tissue. Fibroids can range in size from as small as a pinhead to larger than a melon. Fibroids have been reported weighing more than 20 pounds.
Fibroids originate from the thick wall of the uterus and are categorized by where they grow:
- Intramural fibroids grow within the middle and thickest layer of the uterus (called the myometrium).
- Subserosal fibroids grow out from the thin outer fibrous layer of the uterus (called the serosa). Subserosal can be either stalk-like (pedunculated) or broad-based (sessile).
- Submucosal fibroids grow from the uterine wall toward and into the inner lining of the uterus (the endometrium). Submucosal fibroids can also be stalk-like or broad-based.

The Female Reproductive System
The primary structures in the reproductive system are as follows:
- The uterus is a pear-shaped organ located between the bladder and lower intestine. It consists of two parts, the body and the cervix.
- When a woman is not pregnant the body of the uterus is about the size of a fist, with its walls pressed against each other. During pregnancy the walls of the uterus are pushed apart as the fetus grows.
- The cervix is the lower portion of the uterus. It has a canal opening into the vagina with an opening called the os, which allows menstrual blood to flow out of the uterus into the vagina.
- Leading off each side of the body of the uterus are two tubes known as the fallopian tubes. Near the end of each tube is an ovary.
- Ovaries are egg-producing organs that hold 200,000 - 400,000 follicles (from folliculus, meaning "sack" in Latin). These cellular sacks contain the materials needed to produce ripened eggs, or ova.
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Review Date: 07/26/2010
Reviewed By: Reviewed by Harvey Simon, MD, Editor-in-Chief, Associate Professor
of Medicine, Harvard Medical School; Physician, Massachusetts
General Hospital. Also reviewed by David Zieve, MD, MHA, Medical
Director, A.D.A.M., Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)
