Cervix Flashcards
Cervix function
Junction between uterus and vagina
- Barrier for ascending infection
Holds developing pregnancy
Mucus to facilitate sperm movement
Effaces + dilates in vaginal birth.
Cervix embryology
Differentiation of female genital tract occurs at week 8.
- From indifferent stage
Paramesonephros joins midline to form
- Oviduct
- Uterus
- Cervix
- Upper vagina
Cervical agenesis
Absence of the cervix
- Missing cervix and upper vagina
Probably caused by faulty development of the paramesonephric duct
Cervical dysgenesis
When the cervix is formed but is deformed and non-functional.
- Can be fragmented
Portio vaginalis
The part of the ectocervix that protrudes into the vagina.
Nulliparous vs parous cervix
Nulliparous (never given birth)
- Barrel shape
- Circular external os
Parous
- Bulky
- Slit-like external os
Ectocervix histology
Stratified squamous epithelium
- Provides acidic environmental post-pubertally
Endocervix histology
Simple columnar epithelium
- Production of cervical mucus
- Protective against bacteria
Transformation zone
The region between the old sqaumo-columnar junction and the new SCJ.
- Develops during puberty
Composed of metaplastic squamous tissue
In older women, the transformation zone is higher up the cervical canal
Composition of stroma of the cervix
Mainly collagenous connective tissue
15% smooth muscle
Blood supply and drainage of the cervix
Descending branch of uterine arteries from internal iliac.
Drained by uterine veins and internal iliac veins
Lymphatic drainage of the cervix
Paramterium drains into
- Obturator
- Internal then external iliacs
- Common iliacs
Nervous supply of cervix
Pelvic splanchnic (S2-4)
Pain fibres travel up S2-4
Cervical examinations
Speculum
- Opens vaginal canal to assess the cervix
Cervical mucous
Cervical swab/ smear
Physiological changes of the cervix during pregnancy
Hypertrophy
Softer
Increased vascularity
- Purple tinge
- More susceptible to haemorrhage.
Mucus plug
Ectropion
- Erosion due to oestrogen
- Can cause spotting/ bleeding during pregnancy
Elongation
Cervical infections
Chlamydia
Gonorrhoea
Trichomonas Vaginalis
HPV
Thrush
Cervical cancer stats
- Prevalence
- Incidence
- Mortality
- Demographics
2nd most common cancer in women
Incidence
- 430K per year
Mortality
>200K deaths
Mainly in LEDCs
Predisposing factors to cervical cancer
Smoking
Multiple sexual
Immune comprised
Low socio-economic status
HPV and cancer
Causative type of cervical cancer:
- 16, 18
- 31, 33
Increasing in oropharyngeal cancers in women
Male partners with women with cervical cancer have a higher rate of tongue and tonsil cancer
Anal cancer rates higher in women and their partners with CIN
CIN
Grades 1-3
Cervical intraepithelial neoplasia
- HPV infects the basement membrane and works its way up.
Grade 1
1/3 of cervical wall
2- 2/3
3- Pull penetration
Screening for cervical cytology
- Age range
- Regularity
25-49
- 3 yearly
50-65
- 5 yearly
Abnormality
- Referred for colposcopy
Acetic acid in colposcopy
Acid denatures proteins.
When there are a lot of dyskaryotic cells, it makes them white
High grade CIN = very white
Iodine in colposcopy
Indicative for immature (precancerous tissue)
If tissue is normal
- Dark brown colour change would occur (glycogen)
Abnormal, cells
- Iodine stays yellow in precancerous cells.
Cervical treatment treatment for different grades
1a
- Cone biopsy/ excision
1b
- Radical hysterectomy/ trachelectomy
2a
- Chemo-radiotherapy.
Atrophic vaginalis
Inflammation of the vagina due to thinning from lack of oestrogen
- Typically after menopause
