- What is its function?
- Which are the changes that the uterine cervix undergoes?
- The glands of the uterine cervix and female hormones
What is its function?
The uterine cervix acts as a physical barrier between the vaginal canal and uterus and the outside. The cells of the endocervical canal produce acid and neutral mucus that contains electrolytes like sodium chloride and sugars like glycogen. This mucus forms a sort of plug that blocks the flow of external pathogens from the vagina to the uterus. The mucous plug is not always present and hormones determine its texture. During ovulation the mucus becomes thinner facilitating the flow of sperm from the vagina to the uterus and in the Fallopian tubes. During pregnancy instead, the mucous plug becomes thicker to protect the foetus and block the endocervical canal.
Which are the changes that the uterine cervix undergoes?
Before puberty the cervix constitutes about half the size of the total dimension of the uterus. With development, especially after pregnancy, relative dimensions decrease up to one third of the total, given the longitudinal development of the body. The cervix and the uterus are flexible structures because they contain elastic fibres in addition to muscle fibres. This is important during delivery when the cervix must dilate to allow the passage of the foetus in the vaginal canal. If fertilisation does not take place, the muscle fibres dilate to allow the flow of menstrual material that is essentially flaked endometrial coating. It is this dilatation that causes menstrual pain. Oestrogen hormones and progesterone control all these physiological characteristics of the cervix.
The glands of the uterine cervix and female hormones
The glands of the uterine cervix secrete mucus under the influence of female sexual hormones. With the peak in oestrogens during ovulation, cells secrete viscous mucus to promote the survival and migration of spermatozoids in order for capacitation to occur in the cervical canal. Under the stimulus of progesterone instead the mucus becomes more dense and acid, blocking the passage of spermatozoids when the uterus is not ready for implantation.