Anatomy of the Uterus
Commonly known as the womb, the uterus is the pear-shape, muscular and how part of the female reproductive system. The uterus is located in the lower pelvic area, between the bladder and the rectum. The fallopian tubes, which are connected to the uterus, guide the egg cells from the ovaries to the uterus.
Three Divisions of the Uterus
The uterus is composed of the body or the corpus, the cervix and the isthmus. The one that forms the bulk of the organ is the uppermost part of the body of the uterus. The lining found in the fallopian tubes continues to the uppermost part of the uterus. The point at which the fallopian tube attaches to the uterus is called the fundus. The main function of the body of the uterus is to expand to accommodate the growing foetus. During pregnancy, the fundus is the one that makes it possible to determine uterine growth by palpating it abdominally. It also is the place where you will be able to measure the force related to uterine contraction while the mother is undergoing labour and it serves as the mark in assessing the return of the uterus to its nonpregnant state after childbirth.
When a foetus is not fit to be delivered vaginally, then the physician decides to deliver the baby by way of caesarean section. The isthmus is that part of the uterus commonly cut. A short segment exists between the body of the uterus and the cervix. That short segment is known as the isthmus. This portion of the uterus also enlarges during pregnancy to help the body of the uterus accommodate the growing foetus.
The cervix is situated at the lowest part of the uterus. It joins with the top end of the vagina and is actually one third of the uterus’ total size. About half of the uterus is located above the vagina and the other half extends inside the vagina. The cervical canal is the cavity at the centre of the cervix. The cervical opening of the canal situated where the isthmus and cervix meet is called the internal cervical opening. The cervical opening where the vagina and cervix meet is called the external cervical opening. Another important piece of information to remember is that the level of the external opening is the same or at the level of the ischial spine. This is used to gauge the level of the foetus in the birth canal.
Uterine and cervical coats
The uterus consists of three layers of tissues namely the endometrium or a layer of mucous membrane in the inner part, a layer of muscle fibres called the myometrium and the third and outer layer of connective tissues known as the perimetrium.
For a fertile woman, the ovary will release one egg every month into the fallopian tube. During this instance, the endometrium prepares itself for the possible implantation of a fertilized egg. If the released egg is not fertilized, then it is released by the body and the endometrium sheds and signals the start of the menstrual period. The endometrium is of importance when talking about the menstrual cycle of women and is composed of two layers. The basal layer or the one close to the uterine wall is not affected by any hormones. On the contrary, both oestrogen and progesterone greatly affects the inner glandular portion.
Another vital part of the cervix in terms of pregnancy is the mucous membrane lining of the cervix called the endocervix. At the time of pregnancy, ascending infections are kept at bay because the endocervix becomes plugged with mucous.
The myometrium’s purpose is to prevent the backflow of menstrual blood to the fallopian tubes. It is also responsible for preventing preterm birth by holding the internal cervical opening closed. The myometrium layer is also the site where benign uterine tumours or myoma arise.
It is indeed wonderful to familiarize and understand the grand mechanism involved in the body’s very own cradle of life. Let us not forget that before we came in contact with the world, the uterus was our home.