Your womb or uterus is a hollow, pear-shaped muscular organ in the pelvis. This is where fertilization of an egg (ovum), implantation (hosting) of the resulting embryo, and development of a baby takes place.
Your uterus can stretch exponentially to accommodate a growing fetus, and it undergoes strong contractions to push the baby out during childbirth. But what is inside of it?
Understanding the anatomy of the uterus
The uterus is made of three distinct layers:
- Perimetrium: Outermost layer of the tissue that is made of epithelial cells.
- Myometrium: Middle layer that is made of smooth muscle tissue.
- Endometrium: Inner lining that builds up over the course of a month and is shed if pregnancy does not occur.
The uterus sits behind the urinary bladder and in front of the rectum. It has four sections:
- Fundus: Broad curved area at the top and widest portion of the organ that connects to the fallopian (ovarian) tubes.
- Corpus or the body: Main part of the uterus that starts directly below the level of the fallopian tubes and continues downward, becoming increasingly narrower.
- Isthmus: Lower narrow part of the uterus.
- Cervix: Lowest part of the uterus. Tubular in shape, the cervix opens into the vagina and dilates (widens) to allow the passage of the baby.
What grows inside the uterus during pregnancy?
- Amniotic sac: Thin-walled sac that surrounds the fetus during pregnancy. The sac is filled with liquid produced by the fetus (amniotic fluid). There is a membrane that covers the fetal side of the placenta (amnion). This protects the fetus from injury. It also helps regulate the temperature of the fetus.
- Fetus: Unborn baby from the eighth week of fertilization until birth.
- Placenta: Organ that grows only during pregnancy. The fetus takes in oxygen, nutrients, and other substances from the placenta and gets rid of carbon dioxide and other waste products.
- Umbilical cord: Rope-like cord connecting the fetus to the placenta. It contains two arteries and a vein. It carries oxygen and nutrients to the fetus and waste products away from the fetus.
How does the uterus function?
During a normal menstrual cycle, the endometrial lining of the uterus goes through a process called vascularization during which tiny blood vessels grow and become firmer. This causes the lining to get thicker in preparation for fertilizing an egg released during that cycle. If this does not occur, the uterus sheds the lining as a menstrual period.
If conception occurs, the fertilized egg (embryo) burrows into the endometrium, and this is where the maternal portion of the placenta develops. As pregnancy progresses, the uterus grows, and the muscular walls stretch to accommodate the developing fetus and amniotic fluid.
During pregnancy, the muscular layer of the uterus begins contracting on-and-off in preparation for childbirth. These “practice” contractions (Braxton Hicks contractions) resemble menstrual cramps; some women don't even notice them. After a baby is born, the uterus continues to contract to expel the placenta.
What are abnormal tissues that can develop in the womb?
Sometimes, a woman’s uterus may develop abnormal tissues such as:
Health Solutions From Our Sponsors
Top What Is Inside a Mother’s Womb? Related Articles
When Should I Be Concerned About Pelvic Pain During Pregnancy?Pelvic pain in pregnancy is a common issue that affects many women. Learn what causes pelvic pain in pregnancy, how doctors diagnose pelvic pain in pregnancy, and what you can do to treat pelvic pain in pregnancy.
How Long Does It Take for Your Cervix To Heal After a D&C?The recovery from dilation and curettage (D&C) depends on the type of procedure and type of anesthesia administered. After the surgery, you will be made to rest for about 2-5 hours before going home.
Pregnancy SymptomsWhat are the early signs and symptoms of pregnancy? Can you know before your missed period? Read about nausea and vomiting (morning sickness), bloating, tender breasts, and more. Explore first trimester symptoms of pregnancy and learn what week pregnancy symptoms start.
Am I Pregnant QuizWhat are early pregnancy symptoms? In some women, symptoms range from a missed period to feeling lightheaded. Others may experience typical "morning sickness" and food cravings. Could you be pregnant? Take the quiz!
Embryo vs. Fetus (Differences Between Stages Week by Week)The embryonic stage of pregnancy occurs from the moment of conception until the 11th week pregnancy, or first trimester. During this time the embryo develops major body structures, for example, the organs, heart, and main blood vessels. At this stage the baby's heart begins to beat. The fetal stage, or second trimester is next, and begins during the 11th week of pregnancy, and continues through to week #40. During this time the baby's organs and structures continue to develop, the fetus' gender can be identified, and fetal movement begins. The fetus is about 2 pounds by the 27th week. During the third trimester the baby is the size, and has the characteristics of a newborn. The greatest risk of miscarriage is during the very early stages of pregnancy before a woman even knows she is pregnant.
Fetal DevelopmentTake a peek inside the womb to see the stages of fetal development. Learn how embryos develop and grow during pregnancy. See week after week ultrasound images of your baby in the womb.
How Soon Can You Get Symptoms of Pregnancy?Early symptoms of pregnancy are usually different for every woman. Some women might experience the first symptoms a week or two after conceiving, whereas others don’t feel anything for months. Many women may tell if they are pregnant within two or three weeks of conceiving, and some women know a lot sooner, even within a few days
Is Cervical Stitch Safe During Pregnancy?Cervical stitch, or cervical cerclage, is safe during pregnancy up to 24 weeks. Find out why and how it’s done, as well as the risks associated with the procedure.
What Does Losing Your Mucus Plug Mean During Pregnancy?What is a mucus plug and how do you know you have lost yours? Learn when to see the doctor about losing your mucus during pregnancy.
Pregnancy Myths and Facts QuizBeing pregnant is a delicate time for both mother and baby. Take this pregnancy myths and facts quiz to separate the myths and facts about being pregnant, and learn the truth behind healthy pregnancies!
Pregnancy TestThere are two types of pregnancy tests. One is done in the doctor's office, and tests the blood for the pregnancy hormone, hCG. The other type of pregnancy test can be bought over-the-counter and checks the urine for this hormone. There are many types of home pregnancy tests to choose from. Accuracy of home pregnancy tests depend on how, when, and who uses them, and the brand. It is possible to have a false-negative with a home pregnancy test.
Placenta PreviaPlacenta previa is a condition during pregnancy when the placenta lies low in the uterus either partly or completely blocking the uterus. Women with placenta previa generally deliver their baby via cesarean delivery. There are several types of placenta previa: 1) a low-lying placenta, 2) a partial placenta previa, and 3) a total placenta previa, which covers and blocks the cervical opening. Women who are at risk of placenta previa are women who have delivered a previous baby by cesarean section, and are also at risk of placenta accreta, placenta increta, or placenta percreta.
Pregnancy: Prenatal Care and TestsPrenatal care is important for the health of both mother and baby. Common prenatal tests include ultrasound, amniocentesis, screening for group B strep and chronic villus sampling. Prenatal care also helps detect health conditions related to pregnancy, such as preeclampsia and gestational diabetes.
Stages of Pregnancy: Week by WeekSee pictures on the various stages of pregnancy. See and learn what changes a woman's body goes through and view fetal images of how her baby grows during the 1st, 2nd and 3rd trimesters.
Uterine Fibroids (Benign Tumors of the Uterus)Uterine fibroids are benign (non-cancerous) tumors in the womb (uterus). Most uterine fibroids do not cause symptoms; however, if the fibroid is large enough and in the right location, it may cause symptoms of pelvic pain, abnormal vaginal bleeding, and pressure on the bladder or rectum. Uterine fibroids that remain small and do not grow usually do not need treatment; however, surgery to remove the fibroid may be necessary. Uterine fibroids do not cause cancer; however, there is a rare, fast-growing cancerous called leiomyosarcoma.
Uterine Fibroids PictureUterine fibroids are benign tumors of the uterus (the womb) and the single most common indication for hysterectomy. See a picture of Uterine Fibroids and learn more about the health topic.
What Are Uterine Fibroids? Symptoms, Treatment, PicturesWhat are uterine fibroids? Who gets uterine fibroids, and how can you prevent them? Learn about uterine fibroid treatments, from endometrial ablation to hysterectomy, find out what if any foods can ease symptoms of uterine fibroids, and discover what cancer risks fibroids present.
Uterine Fibroids: Test Your Medical IQWhat causes uterine fibroids? Are fibroids serious? What is the best treatment for uterine fibroids? Could you be at-risk? Take this quiz to learn all about fibroids.