The cervix in health and disease Flashcards
Anatomy of the cervix
Size and shape vary widely with age, hormonal state and parity
In nulliparous females it is barrel shaped with a small circular external os at the centre of the cervix
In parous women, cervix is bulky and the external os becomes slit like
Histology of the normal cervix
The ectocervix is covered by non-keratinising stratified squamous epithelium, either native or metaplastic in continuity with the vaginal epithelium
Squamous epithelium is composed of multiple layers
Endocervix is lined by simple columnar epithelium that secretes mucus
Mucinous columnar epithelium lines the surface and the underlying layers
Layers of the cervical squamous epithelium
Basal
Parabasal
Intermediate
Superficial
The stroma of the cervix
Collagenous connective tissue
Approx 15% smooth muscle fibres
Blood supply of the cervix
Uterine artery, descending branch
Venous drainage follows the arteries
Lymphatic drainage of the cervix
Parametrium
Obturator
Int iliacs
Ext iliacs
Common iliacs
Nerve supply of the cervix
Pain fibres with the parasympathetic 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
Physiological changes 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 the cervix
Cervical ectopy ‘erosion’
- effect of oestrogen
Atrophic ‘cervicitis’
- lack of oestrogen
Cervical infections
Chlamydia
Gonorrhoea
Trichomonas vaginalis
HPV
Cancer and precancerous changes
Worldwide cervix cancer is the 2nd most common cancer among 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
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
Male partners of women with cervical cancer
Have higher rates of tongue and tonsil cancer
