The uterus is one of the female reproductive organs. Its shape resembles a pear and is located inside the pelvis, where it is attached by strong uterine ligaments. The average length of a uterus of a woman, who has not yet given birth is 7,5-8 cm, its width in its upper part is approximately 5 cm and its thickness is 2,5 cm. These measurements are larger in women, who have already given birth. The basic purpose of the uterus is containing, nutrition and development of a fertilized egg, which develops into a new person. The urinary bladder is located in front of the uterus inside the pelvis, behind the uterus rests the rectum and a part of colon.
Composition of the uterus
We discern two basic parts of the uterus, the body and the cervix. The body forms a single cavity. In its upper part are the uterine horns, to which the fallopian tubes connect. The cervix connects the uterine body with the vagina. The uterus has three layers, the uterine mucosa, musculature and the surface layer. Nerves and blood vessels run through the surface layer. The uterine musculature is composed from smooth muscles, which cannot be controlled by will. It is arranged in four layer, in which the muscle fibers have a certain direction and which pass into each other. This allows for the firmness of the walls. The muscle fibers have the ability of increasing their volume several times, which is important during pregnancy while the fetus is growing. During childbirth the musculature contracts rhythmically, which leads to the expulsion of the fetus out of the body. Uterine mucosa is under the influence of hormonal stimulation and undergoes a series of changes during the menstrual cycle.
Changes in the uterine mucosa
The uterus is an organ, which is specifically adapted for accepting a fertilized egg and providing its nutrients up until the point when placenta develops. Its mucous layer undergoes regular changes under the influence of female reproductive hormones, these changes are known as an ovarian and menstrual cycle, which most commonly lasts for 28 days.
The ovarian cycle mainly influences the ovaries, in which the female reproductive cells, the eggs, are grown. In the first phase of this cycle an egg grows within the ovary and a large amount of female reproductive hormones, the estrogens, are released. Afterward, ovulation, the release of a mature egg from the ovary to the fallopian tube, occurs. There it can be fertilized by sperm. In the second phase of the ovarian cycle a corpus luteum is created out of the remnants of the released egg. The corpus luteum then produces a large amount of female sex hormone, progesterone in this case, which prepared the uterus for eventual pregnancy.
The uterine mucosa, influenced by progesterone, grows and prepares itself for accepting a fertilized egg, which is traveling to it through the fallopian tubes. Should the egg not be fertilized, the levels of sex hormones sharply drop and the menstrual phase begins, during which the overabundance of prepared uterine mucosa, together with the unfertilized egg, are washed out of the body with blood. Menstrual bleeding lasts for 5 days on average. After that, the uterine mucosa regrows and regenerates, influenced by estrogens. The cycle repeats.
If the egg is fertilized, menstrual bleeding doesn't occur and pregnancy begins. The uterus undergoes many changes during pregnancy. It pear-like shape turns into a round or oval one, its volume increases from 2-3 ml to 5000 ml and its weight grows from 60g to almost 1 kg. Thanks to the ability of muscular fibers to increase their volume, the uterus can increase its size together with the growing fetus and reach up to the rib arcs at the end of the ninth month of pregnancy. Placenta develops in the uterus for providing nutrition to the fetus. The umbilical cord, which connects the placenta and the fetus, provides a supply of oxygen and nutrients and removes metabolic waste the fetus has produced. Placenta also produces hormones, which prepare the mother's organism for correct growth and development of the fetus. Another necessary part of the uterus during pregnancy is amniotic fluid. This clear liquid surround the fetus in the uterus and protects it from impact and outside pressure. It also allows movement for the fetus, which the mother can sense. Hormonally directed contractions of the uterine musculature occur at the end of the pregnancy, helping expel the fetus from the uterus into the birth canal and out of the body.
Diseases of the uterus
The uterus is an extremely important organ. Its removal means the loss of reproductive abilities as well. Unfortunately, a common type of uterine diseases are cancerous diseases, which generally require the removal of uterus. Another disease is endometriosis. The uterus is also affected by congenital development defects and position changes. An important preventative approach to uterine diseases relies on regular gynecological examinations, which should happen at least once a year. These examinations have their significance even in advanced age, but unfortunately many women avoid them. Please pay attention to prevention, expedient diagnosis and thorough treatment of any reproductive organ diseases.
Uterine cancer is among the most common cancerous diseases of the reproductive organs. It mainly affects women after menopause. The main problem of uterine cancer is that is has no symptoms for a long time and has a tendency of affecting nearby organs and spreading through the body. Among the main risk factors leading to uterine cancer are advanced age, obesity, hormonal influence, early onset of menstruation, late onset of menopause and heredity. The main symptom is bleeding into uterus and a resulting bloody vaginal discharge. The bleeding may be of varying strengths, from small staining to significant bloodless. Other symptoms are abdominal pains, painful intercourse and urination, loss of weight and of appetite. These however mainly signify a late stage of the disease. The main course of treatment is a removal of the uterus, often with the fallopian tubes as well. During an advanced stage the surgical procedure is coupled with chemotherapy, which are aggressive anti-cancer drugs.
A myomatosis is a benign cancerous disease afflicting the uterine musculature. It is the presence of muscular tumors (myomas) of varying sizes in the uterus. It mainly affects women between 30 and 50 years of age. The exact reason for their development is unknown, however. Usually, myomatosis causes no issues and requires no treatment. If it does cause any problems however, it is most commonly due to the larger size of the tumors. The most common symptom is a strong and prolonged menstrual bleeding. Abdominal pains, pain during intercourse or issues with evacuating can be present as well. With women who plan no pregnancies,the treatment used is most commonly a surgical removal of the entire uterus. Should the woman plan any pregnancies, only the tumors are removed.
Endometriosis is a disease, during which the uterine mucous layer is found outside of the uterus, usually on the ovaries, the fallopian tubes and the urinary bladder. This mucosa, just like the one in uterus is under the influence of female sex hormones an changes during menstruation. During it small bleeding occurs in the areas with mucosa, and small cavities and scars eventually form. These scars then lead to adhesions, which are the reason for infertility in 50% of all endometriosis cases. The reason for endometriosis is not currently understood. The most probable theory for why the uterine mucosa can be present outside of the uterus is the possibility that during menstruation, not all the mucous layer is washed out of the body. Par of it travels through the fallopian tube into the abdominal cavity, where it can implant itself. The main symptoms of endometriosis is a long lasting abdominal pain, which worsens during menstruation. Treatment combines a surgical removal of the mucous layer in affected areas together with applying hormonal drugs which prevent a remission.