5. The cervix in health and disease Flashcards
What is the cervix?
the neck of the womb
Opening to vagina is called…
external os
Ectocervix
portio vaginalis and external os
Cervix in nulliparous women
Barrel shaped with a small circular external os at centre of cervix
Cervix in parous women
cervix is bulky and external os becomes transverse slit-like
What tissue type is the vagina and why?
Stratified squamous epithelium
to cope with the harsh acidic environment of the vagina
What type of tissue is the ectocervix?
non-keratinised stratified squamous
because produces mucous
What happens to the transformation zone with age?
emerges more during young adulthood, then recedes again after the menopause
Stroma of cervix made of…
Collagenous connective tissue
Approx 15% smooth muscle fibres
Blood supply of cervix
Uterine artery, descending branch
Venous drainage follows the arteries
Lymphatic drainage
parametrium, obturator, int. iliacs, ext. iliacs, common iliac
Nerve supply
pain fibres with the parasympathetics to S2, S3, S4
(uterine to T11 and T12 in addition)
Functions of the cervix
Produces mucus to facilitate sperm migration
Acts as a barrier to ascending infection
Holds a developing pregnancy in place
Effaces and dilates to enable vaginal birth
Mucous changes in the cervix
Midcycle mucous is thin and watery then thickens
Women can assess their fertility by seeing thickness of cervical mucous
Physiological changes of cervix in pregnancy
Hypertrophies, but not as much as the uterus
Becomes softer
Increased vascularity/venous congestion, “purple tinge”
Glands distended with mucus, “mucus plug”
Prominent ectropion
Remains elongated until the onset of labour
Physiological changes on cervix
Cervical Ectopy “Erosion”
effect of oestrogen
Atrophic “Cervicitis”
lack of oestrogen
Cervical infections
Chlamydia
Gonorrheoa
Trichomonas vaginalis
HPV
Cancer and precancerous changes
Worldwide Cervix cancer is the 2nd most common cancer amongst women
430,000 cases each year
> 200,000 deaths
80% occur in LEDC’s
Causes of cervical cancer
HPV
Predisposing factors Smoking Multiple sexual partners Immune compromise Low socio-economic status
HPV infection
HPV is a very common infection which is easily transmitted through close sexual contact
Acquisition can occur via skin to skin contact in the genital area
Up to 95% of sexually active women will be infected with HPV at some point in their lives
Condoms reduce the risk of infection but are not fully protective
The number of oropharyngeal cancers in women is rising of which an increasing proportion are HPV related
Male partners of women with cervix cancer have higher rates of tongue and tonsil cancer
Anal cancer rates are higher in women with CIN and their male partners
HPV infection
Infection starts at basememnt membranes where cells are more naïve, then gains entry into the nucleus and cause precancerous changes (dyskariosis). If this change involves the lower 1/3 of basment membrane that’s CIN I, if lower half CIN II, if full thickness then its CIN III
Smear test follow-up
Cytology, colposcopy, histology, treatment by ablation or excision
The NHSCSP
Women are invited for cervical cytology sampling
25 - 49yrs 3 yearly 50 – 65yrs 5 yearly
Referred for colposcopy if cytological abnormalities
Cervical cancer current treatment
1a cone biopsy/excision
1b radical hysterectomy/trachelectomy
2a chemo-radiotherapy
Radical trachelectomy
Get rid of cervix and attach to the top of the vagina, add stitch in top of vagina to hold future pregnancies but will have to give birth by C-section
