الفهرس 
UTERINE CERVIX ANATOMYOnly 14 pages are availabe for public view
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Abstract
The cervix is continuous with the lower part of the uterus. Its proximal portion is located in the abdomen and its distal portion in the vagina. It has a narrow central canal which runs along its entire length, connecting the uterine cavity and the lumen of the vagina. The opening of this canal into the uterus is called the internal os and the opening into the vagina the external os. It is a firm, cylindrical structure. (Myers et al, 2015)
The length of a normal adult non-pregnant cervix is approximately 30 mm, with an antro-posterior diameter ranging between 20 and 25 mm and a transverse diameter of 25–30 mm, although considerable variations occur due to age, parity and stage of menstrual cycle. (Nott et al, 2016)
It is the part of the uterus responsible for maintaining pregnancy till term. As long as the cervix remains long and firm and its internal orifice (os) is closed, it can withstand enlargement of the uterine contents and resultant growing pressure. During normal pregnancy, the uterine cervix undergoes physiological changes in the extracellular matrix in order to reduce stiffness, but increase its tensile proprieties. The cervix ripens prior to delivery, then effaces and dilates with contractions of the uterus. (Kim et al, 2017)
Ripening of the cervix can be assessed using the Bishop score and ultrasonographically determined length of the cervical canal and internal os. Consistency is one of the cervical properties that change during the course of the maturation process. Until recently, cervical consistency has been assessed only manually, but in 2007, the first report on elastographic imaging of the cervix during pregnancy has been published. (Swiatkowska-Freund et al, 2011)
Cervical incompetence is an important contributor to pre-term birth and second trimester pregnancy loss. It is defined as the inability to support a full-term pregnancy because of a functional or structural defect of the cervix. It is reported that the rate of cervical incompetence is between 0.1% and 2%, and is estimated to account for 15% of the recurrent pregnancy losses between 16 and 28 weeks. Identifying patients threatened with cervical incompetence and trea.