The Cervix Version 1

Carefully mapped lateral wall of the Cervix of a 20 year old virgin (reported by Emeritus Professor Erik Odeblad, Department of Medical Biophysics, University of Umeå, S-90187, Umeå, Sweden)
The cervix is at the bottom of the uterus and channels sperm from the vagina through to the uterus. The figure shows the crypt types in the cervix wall which secrete the corresponding mucus type: F F mucus G G mucus L L mucus P P mucus S S mucus Z Z granules These mucus produce the symptomatic pattern of fertility and infertility which underpins the Billings Ovulation Method.
L mucus - eliminates low-quality sperm and provides a structure to support the S and P mucus. Produces a wet, sticky sensation at the vulva.	G mucus - impenetrable gestagenic mucus formed in the lowest cervical crypts. Prevents sperm entry to the cervix and is part of the immune system which protects the woman's reproductive system from infection.
F mucus - comes from the cells scattered throughout the length of the cervical canal and has no known special function. Z granules - the enzyme in the Z granules combines with the P mucus to create a liquifying effect.	Artist's impression of mucus secretions
S mucus - forms string-like channels and provides transport ("swimming lanes") for sperm cells. Produces a wet, lubricative sensation at the vulva.	P mucus - there are a number of sub-types of this mucus, the most relevant for fertility are P2 and P6. P2 could be present as early as the beginning of the fertile phase possibly having a role in liquifying the G mucus. P6 is mostly confined to the upper part of the cervix, occurring close to the Peak of fertility, and having a role in conveying sperm. It creates a very wet and lubricative sensation at the vulva.
Bibliography Billings, Evelyn L. and Billings, John J., Teaching the Billings Ovulation Method, Part 2, Variations of the Cycle and Reproductive Health, Ovulation Method Research and Reference Centre of Australia, Melbourne, 1997. Billings, Evelyn and Westmore, Ann, The Billings Method, Ann O'Donovan Pty. Ltd., Melbourne, 1997. Odeblad, Erik, "The Discovery of Different Types of Cervical Mucus and the Billings Ovulation Method", Bulletin of the Natural Family Planning Council of Victoria, Vol 21, No. 3, September 1994.