Cervix

The cervix is a tube or cone-shaped structure which comprises the lower third of the uterus. Over the course of a woman's lifetime, the cervix undergoes changes in response to cyclical shifts in hormones. This structure is most notably involved in menstruation and delivery of a baby. The cervix is a common location for cancers to develop, so screening for cervical cancer is often recommended on a regular basis so that any signs of cellular changes can be quickly identified and addressed.

Also known as the neck of the uterus, the cervix is easy to spot on anatomical drawings, although it is often labeled in a way which suggests that the os, or opening, is the whole cervix. The cervix is the narrowed area at the base of the uterus which opens into the vagina. It is important to note that the precise structure of the uterus can vary from person to person, and that small variations are not a cause for concern.

This anatomical structure is made from smooth muscle which forms a tube. During menstruation, the tube enlarges and the os opens so that the endometrium, the lining of the uterus, can be successfully shed. This can take several days. Sometimes "spotting," in which small drops of blood appear throughout the menstrual cycle, can also occur, especially in people who have certain gynecological conditions. During the menstrual cycle, the cervix secretes varying amounts of mucus, which plays a role in fertility.

During pregnancy, the cervix stays closed to keep the uterus sealed in order to protect the developing fetus. In the last weeks of pregnancy, the cervix starts to thin in preparation for dilating for labor and delivery. During the process of dilation, it opens wide to allow the baby to move through and into the vagina for delivery. Dilation can be assessed with a quick examination to determine how far labor has progressed. After delivery, the entire uterus will tighten back up to return to its normal size.

In screening for cervical cancer, sometimes false positives are returned. This occurs most commonly because an inflammation or infection has caused abnormalities in the cervical cells which will resolve once the cause of the abnormalities is addressed. When positive results are returned, additional follow up screenings may be recommended to determine whether or not additional action needs to be taken.

Cervix Dilation

Cervix dilation is also known as dilatation, it is a gradual process where the mouth of the cervix widens from 0-10 centimeters (4 inches in width) during the course of labor. When the cervix is dilating or opening it is considered to be a sign that labor is on the way.

Cervix Dilation is the width of the opening of the cervix as baby makes its descent head down.

The cervix is a thick-walled canal about 2 cm thick and tightly closed. Though hormones will soften and thin it, first-stage contractions are required to dilate and thin the cervix.

Contractions will widen the diameter of the cervix. Labor is popularly divided into 2 phases: active and latent with the transition phase in between. During the latent phase dilation reaches about 3-4 cm; the cervix widens to about 7 cm in the active phase with most of the hard work i.e. intense labor during the transition phase where full dilation is achieved. Repeat contractions stretch the cervix to a full 10 cm.

Doctors often gauge the labor progress by the dilatation of the cervix. Vaginal exams to measure how far you are dilated by feeling the opening of your cervix are commonplace during labor.

Dilation is measured in centimeters. There are 2½ cm to an inch. Often fingers are also used to estimate the rate of dilation although its accuracy is debatable since finger sizes differ in individuals. For example, when dilation is said to be 3-4 cm, it is equivalent to two-three fingers; when a woman is fully dilated she is said to have entered the 2nd stage of labor with her cervix having reached 10 cm (equal to five fingers).

Dilatation in first time mothers can take hours or even days to reach the 3-4 cm (1-2 inches) of the latent phase. It can only take place once the cervix has softened. Dilation process moves slowly initially during the first stage and picks up momentum with the aid of intense contractions during the transition stage once you approach the 10 cm mark.

Pain intensifies when the cervix is fully dilated and it then unifies with the body of the uterus to become one continuous pathway through which the baby passes through.

First time mothers have longer labors because effacement and dilation are two separate processes; effacement precedes dilation. In subsequent deliveries dilation and effacement occur concurrently, shortening the labor process.