cervix
Enable an AI agent to identify a cervix, represent its observed anatomical and clinical state, and determine which assessments or interventions require further evidence or clinical authorization.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
Researched by: Codex + Grok
Purpose and description
Enable an AI agent to identify a cervix, represent its observed anatomical and clinical state, and determine which assessments or interventions require further evidence or clinical authorization.
The uterine cervix is the fibromuscular inferior segment of the uterus whose canal joins the endometrial cavity at the internal os to the vaginal lumen at the external os, with a squamous ectocervix and a glandular endocervix meeting at a shifting squamocolumnar junction and transformation zone.
It can be Locate and describe cervical structures on documented examination or imaging.; Record cervical measurements and compare observations made with compatible methods and context.; Map abnormalities and specimen results to specific cervical regions.; Identify incomplete visualization, uncertain anatomy, or missing evidence that limits interpretation.; Support clinician review of proposed cervical sampling or intervention using documented anatomy, context, consent, and authorization.; Track local anatomical changes and healing after a cervical procedure..
Distinguishing features
Identify the lower uterine portion that connects the uterine cavity with the vagina; a visible vaginal projection alone does not establish its full extent.
Distinguish the cervical canal from the uterine cavity and vaginal lumen by its position between the internal and external cervical openings.
Distinguish ectocervical tissue from the surrounding vaginal wall through anatomical continuity and examination landmarks rather than appearance alone.
Distinguish the cervix from the uterine corpus using the canal, internal opening, and documented anatomical or imaging boundaries.
Treat cervical polyps, masses, and postoperative remnants as findings or altered structures requiring localization, rather than automatically identifying them as an intact cervix.
Scope
+ Cervical identity, anatomical boundaries, and continuity with the uterus and vagina
+ Ectocervix, endocervical canal, cervical openings, and epithelial transition regions
+ Cervical dimensions, patency, integrity, and examination visibility
+ Changes associated with reproductive stage, pregnancy, and labour
+ Local abnormalities, specimens, and effects of cervical interventions
- Uterine corpus and endometrial conditions beyond their relationship to the cervix
- Vaginal and vulvar anatomy and disease outside cervical involvement
- Whole-person fertility, pregnancy, and labour management
- Systemic infection and immune status beyond their relevance to cervical observations
- Cancer staging and treatment pathways beyond local cervical findings
- Screening programme eligibility, scheduling, and population policy
Characteristics
- Anatomical presence and configuration
- Present, partially retained, absent, uncertain; configuration described Prevents assumptions that an intact cervix exists after surgery or in an anatomical variant.
- Continuity with neighbouring structures
- Documented relationships to uterine corpus, uterine cavity, vagina, and vaginal fornices Establishes identity and locates observations within the correct organ.
- Cervical length
- mm, with method, landmarks, date, and reproductive context Supports comparison while preventing measurements taken under different conditions from being treated as equivalent.
- Cervical opening and canal patency
- Closed, patent, narrowed, obstructed, uncertain; opening and assessment method specified Describes the cervical passage and constraints on examination or access.
- Cervical dilation
- cm, with assessed opening, method, time, and clinical context Records opening size without interpreting an isolated value as a complete labour assessment.
- Cervical effacement
- Percent when clinically assessed, with method and time Captures a pregnancy-related cervical change separately from dilation and measured length.
- Epithelial landmarks and visibility
- Squamocolumnar junction and transformation zone described as fully visible, partly visible, not visible, or unassessed Qualifies what an examination can establish about the relevant tissue regions.
- Local abnormality
- Observed lesion, bleeding, discharge, inflammation, injury, or other finding; site and evidence specified Separates observable changes from an unconfirmed cause or diagnosis.
- Cervical specimen linkage
- Specimen identifier, sampled site, collection method, collection date, and reported result Connects laboratory evidence to the tissue or material actually sampled.
- Intervention-related alteration
- Procedure, date, affected region, retained anatomy, healing observations, and uncertainty Explains altered landmarks and constrains later measurements or procedures.
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 28 questions.
Cervical identity and boundaries Establishes which structure is the cervix and how much of it is present.
Cervical observations are meaningful only when distinguished from adjacent vaginal and uterine structures.
Uterovaginal continuity
Locates the cervix through its connections and openings.
Cervical anatomical identification
Records the landmarks supporting identification of cervical tissue and canal.
- Which examination, imaging, or operative landmarks identify this structure as the uterine cervix? definition
- Where are the observed boundaries with the uterine corpus and vagina, and which boundaries remain uncertain? boundary
Retained cervical anatomy
Describes intact, variant, or surgically altered cervical anatomy.
Cervical presence and configuration
Separates confirmed anatomical presence from assumptions based on history or incomplete examination.
- Is the cervix intact, partly retained, absent, or uncertain, and what evidence establishes this? provenance
- Does a variant or prior procedure change which tissue and openings belong to this cervical instance? boundary
Cervical regions and examination Represents cervical tissue regions and the limits of their observation.
A visible ectocervix does not establish the state of the endocervical canal or all epithelial transition tissue.
Epithelial region localization
Locates ectocervical, endocervical, and epithelial transition observations.
Cervical tissue landmarks
Records the tissue region assigned to each observation and the evidence for that assignment.
- Does the observation concern the ectocervix, endocervical canal, squamocolumnar junction, or transformation zone? boundary
- Which landmarks or specimen descriptions support that regional assignment? provenance
Cervical visualization limits
Captures what a particular examination could and could not inspect.
Cervical examination coverage
Qualifies observations by visibility, access, and examination method.
- Which cervical surfaces and epithelial landmarks were fully visible, partly visible, or not visualized? measurement
- What further assessment, if any, is needed before drawing conclusions about unobserved cervical regions? action
Cervical form and reproductive change Records cervical dimensions, passage state, and context-dependent change.
Cervical length, opening, and effacement require distinct observations and reproductive context.
Cervical dimensions and passage
Describes cervical length and the state of the canal and openings.
Cervical geometry and patency
Anchors measurements and passage assessments to specified landmarks and methods.
- What cervical length or opening measurement was obtained, using which landmarks, units, and method? measurement
- Which opening or canal segment is described as patent, narrowed, or obstructed, and how was that established? provenance
Pregnancy and labour context
Places cervical change within the recorded reproductive and temporal context.
Contextualized cervical change
Keeps dilation, effacement, and length observations distinct while allowing supported comparison over time.
- What pregnancy status, gestational age when applicable, and examination time accompany the cervical observation? provenance
- How have dilation, effacement, or length changed across observations with sufficiently comparable methods? measurement
Cervical abnormalities and diagnostic evidence Links local observations to specimens and interpretations without collapsing them into a single diagnosis.
Cervical appearance, HPV testing, cytology, and histology provide different kinds of evidence.
Localized cervical abnormalities
Describes the position, extent, and observable properties of local changes.
Cervical abnormality map
Records lesions and other abnormal observations without assuming their cause.
- Where is the abnormality relative to the external opening, cervical regions, and a documented orientation convention? boundary
- What size, surface change, bleeding, discharge, or tissue disruption was actually observed, and by which method? measurement
Cervical specimens and results
Connects diagnostic reports to their collection sites, methods, and limits.
Cervical diagnostic evidence link
Preserves distinctions between test results, tissue diagnoses, and unresolved interpretation.
- Which specimen, collection site, date, adequacy statement, and report support each HPV, cytology, or histology result? provenance
- What conclusion does the report establish, and what remains unresolved because of sampling limits or discordant evidence? boundary
Cervical interventions and local outcomes Represents proposed and completed cervical procedures and their local consequences.
Sampling, excision, suturing, and other procedures can alter cervical tissue, access, and later interpretation.
Cervical procedure readiness
Connects a proposed action to its target, clinical purpose, and documented prerequisites.
Cervical action constraints
Records the evidence a responsible clinician needs to evaluate a proposed cervical procedure.
- What cervical region would be sampled, traversed, removed, or supported, and for what documented indication? action
- Are relevant anatomy, pregnancy context, prior procedures, consent, and clinician authorization documented for this action? action
Postprocedure cervical state
Tracks retained tissue, altered landmarks, and observed local recovery.
Cervical procedure effects
Separates the recorded procedure from its demonstrated anatomical and healing outcomes.
- What cervical tissue was removed or altered, or what material was placed, according to the procedure record? provenance
- What subsequent observations establish healing, residual abnormality, narrowing, or other local change? measurement
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Kinds and varieties
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Ectocervix (exocervix; portio vaginalis)
- Endocervix (endocervical canal and its columnar mucosa)
- Transformation zone (IFCPC type 1, 2, or 3)
- Supravaginal cervix (portio supravaginalis)
- Nulliparous cervix (round, punctate external os)
- Parous cervix (transverse slit os; often scarred)
- Pregnant or labouring cervix (shortened, effaced, dilating)
- Congenitally variant cervix (hypoplasia, duplication, historical DES-associated forms)
- Which of these kinds and varieties hold for the sense of cervix this model covers, and on what evidence? provenance
Identifiers and schemes
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Wikidata - Q131712 - Item for the uterine cervix
- UBERON - UBERON:0000002 - uterine cervix
- FMA - 7877 - Cervix of uterus
- SNOMED CT - 71252005 - Structure of uterine cervix
- MeSH - D002584 - Cervix Uteri
- Terminologia Anatomica (TA98) - A09.1.03.010 - Cervix uteri
- ICD-O-3 topography - C53 - C53.0 endocervix; C53.1 exocervix; C53.9 cervix uteri NOS
- NCIt - C12311 - Cervix Uteri
- Which of these identifiers and schemes hold for the sense of cervix this model covers, and on what evidence? provenance
Standards and regulation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- FIGO staging classification for carcinoma of the cervix uteri (International Federation of Gynecology and Obstetrics)
- The Bethesda System for Reporting Cervical Cytology (international cytology consensus; NCI-originated)
- WHO Classification of Tumours of the female genital tract (IARC/WHO)
- IFCPC colposcopic terminology, including transformation-zone types (International Federation for Cervical Pathology and Colposcopy)
- ASCCP risk-based management consensus guidelines for abnormal screening (American Society for Colposcopy and Cervical Pathology)
- WHO guideline for screening and treatment of cervical pre-cancer lesions (World Health Organization)
- National screening programmes and USPSTF/ACS-equivalent recommendations that set age, interval, and test (cytology, HPV, or VIA)
- HPV immunization policy (WHO SAGE and national schedules), which targets the main causal pathway of cervical cancer
- Terminologia Anatomica (FIPAT/IFAA) for anatomical nomenclature
- Which of these standards and regulation hold for the sense of cervix this model covers, and on what evidence? provenance
Real-world use
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Visualized on speculum examination and colposcopy; sampled for cytology (Pap) and high-risk HPV testing
- Mechanical gateway of labour: assessed for dilation, effacement, consistency, and position (Bishop score) before induction or during birth
- Canal used as the route for IUD insertion, endometrial biopsy, hysteroscopy, and other access to the uterine cavity
- Surgical target of LEEP/LLETZ, cold-knife cone, trachelectomy, and hysterectomy that includes the cervix
- Cervical-length measurement by transvaginal ultrasound in pregnancy to stratify preterm-birth risk and to select cerclage or progesterone
- Site of infectious work-up (e.g. chlamydia, gonorrhoea) when cervicitis is suspected
- Which of these real-world use hold for the sense of cervix this model covers, and on what evidence? provenance
Typical measurements
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Anatomical length, non-pregnant adult - 25-40 - mm
- Transverse diameter, non-pregnant adult - 20-30 - mm
- Mid-trimester cervical length on transvaginal ultrasound - 30-50; short often defined as <25 - mm
- Cervical dilation in labour - 0-10 (fully dilated) - cm
- Cervical effacement in labour - 0-100 - %
- Which of these typical measurements hold for the sense of cervix this model covers, and on what evidence? provenance
Failure modes and hazards
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Persistent high-risk HPV infection leading to CIN and invasive cervical carcinoma
- Cervical insufficiency with mid-trimester pregnancy loss or spontaneous preterm birth
- Stenosis after surgery, radiotherapy, or menopause, blocking sampling, menses, or labour
- Obstetric laceration of the cervix, sometimes extending into the vaginal fornix or lower uterine segment
- Infectious cervicitis (including N. gonorrhoeae and C. trachomatis) and ascending pelvic infection
- Iatrogenic harm from cone/LEEP (bleeding, stenosis, later preterm birth) or from forced dilation
- Rare cervical ectopic pregnancy, with high haemorrhage risk
- Obstructed labour or failed induction when the cervix does not dilate or the os cannot be negotiated
- Which of these failure modes and hazards hold for the sense of cervix this model covers, and on what evidence? provenance
Regional variation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Lay and clinical names: neck of the womb (UK), col de l'utérus (French), cuello uterino (Spanish), Gebärmutterhals (German), шейка матки (Russian)
- Screening test and interval: primary HPV testing vs cytology vs co-testing vs visual inspection with acetic acid (VIA) in many low-resource programmes
- Start age and stop age of organised screening differ across national programmes
- Treatment of precancer: LEEP/LLETZ vs cryotherapy vs thermal ablation depending on resources and training
- Oncology practice may report FIGO stage, TNM, or both
- HPV vaccine valency, sex-neutral policy, and school-based delivery vary by country
- Which of these regional variation hold for the sense of cervix this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Uterine corpus (and isthmus) - Separated at the internal os; corpus is lined by endometrium and forms the body of the uterus, whereas the cervix has endocervical mucosa and a fibrous wall
- Vagina - Separated at the external os and fornices; vagina is a fibromuscular tube without an endocervical canal or cervical glands; ectocervical and vaginal squamous epithelia are continuous but topographically distinct
- Lower uterine segment (in pregnancy) - Expanded isthmus above the internal os, not the cervix proper; ultrasound identifies the internal os and closed cervical length below it
- Endometrium / endometrial carcinoma - Different mucosa and typical tumour immunoprofile (endocervical mucinous/HPV-related vs endometrioid); origin is assigned by site, morphology, HPV/p16, and markers such as vimentin and hormone receptors when the lesion spans the isthmus
- Parametrium (paracervical tissue) - Lateral connective tissue and vessels around the cervix, not cervical stroma; distinguished surgically and on imaging as extra-cervical spread
- Which of these neighbouring kinds and how to tell them apart hold for the sense of cervix this model covers, and on what evidence? provenance
Sources
- Gray's Anatomy: The Anatomical Basis of Clinical Practice, 42nd ed. Elsevier (Standring, ed.) - Gross anatomy of cervix uteri, internal and external os, ectocervix vs endocervix, relations to vagina and uterine corpus
- Terminologia Anatomica. Federative International Programme for Anatomical Terminology / IFAA - Standard anatomical name cervix uteri and related terms (portio vaginalis, canalis cervicis)
- Female Genital Tumours, WHO Classification of Tumours, 5th ed., vol. 4. IARC/WHO, 2020 - Pathologic kinds of cervical epithelium and neoplasia; distinction from corpus and vagina
- The Bethesda System for Reporting Cervical Cytology, 3rd ed. Springer (Nayar and Wilbur, eds.), 2015 - How the cervix is sampled and classified in screening practice
- Revised FIGO staging for carcinoma of the cervix uteri. International Journal of Gynecology & Obstetrics (Bhatla et al.), 2019 - Oncologic staging that treats the cervix as the primary organ of origin
- WHO guideline for screening and treatment of cervical pre-cancer lesions for cervical cancer prevention, 2nd ed. World Health Organization, 2021 - Screening, ablation, and excision practice; regional differences in VIA vs HPV vs cytology
- Cervix. NCI Dictionary of Cancer Terms. U.S. National Cancer Institute - Clinical definition used in oncology and screening communications
- UBERON:0000002 uterine cervix. Uberon anatomy ontology - Stable ontology identifier and placement relative to uterus and vagina
What the second pass must settle
- Which authoritative anatomical convention should define the cervical boundary with the uterine isthmus across imaging, examination, and surgical records?
- Which standardized terminology should represent transformation-zone visibility and examination adequacy across clinical settings?
- What method-specific comparability rules are needed for cervical length, dilation, and effacement observations?
- How should congenital variants and postoperative cervical remnants be represented while preserving the registry's single-entry granularity?
- Which current clinical guidelines should supply procedure-specific prerequisites and escalation rules without embedding whole-person management in this anatomical model?