gallbladder
Enable an AI agent to recognise a gallbladder, record evidence about its anatomy and condition, and distinguish supported next actions from decisions requiring clinical assessment.
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 recognise a gallbladder, record evidence about its anatomy and condition, and distinguish supported next actions from decisions requiring clinical assessment.
A hollow, pear-shaped, muscular extrahepatic viscus seated in the gallbladder fossa of the liver that stores and concentrates hepatic bile and ejects it through the cystic duct into the common bile duct under cholecystokinin-mediated contraction.
It can be Associate imaging, operative and pathology observations with the correct gallbladder or remnant.; Compare dimensions, wall findings and contents across examinations with their acquisition conditions preserved.; Record storage and emptying evidence without inferring function from appearance alone.; Flag unresolved organ-local findings for qualified clinical review.; Record clinician-directed surveillance, drainage or removal and the resulting anatomical state..
Distinguishing features
Assess whether the structure is a sac with a fundus, body and neck, rather than a tubular segment of the biliary ducts.
Seek anatomical continuity from its neck into the cystic duct; record whether this connection is demonstrated or merely inferred.
Assess its relationship to the liver's gallbladder fossa, allowing for anatomical variants rather than making typical location mandatory.
Distinguish the organ wall and lumen from an adjacent cyst or fluid collection using anatomical continuity and imaging evidence.
When no gallbladder is visualised, distinguish nonvisualisation from documented removal or confirmed congenital absence.
Scope
+ Organ identity, presence, location, morphology and anatomical variation
+ Gallbladder wall, lumen and contents
+ Bile storage and emptying observations
+ Organ-local abnormalities and their evidential status
+ Gallbladder-specific procedural changes, remnants and follow-up observations
- Hepatic bile production and overall liver function
- The biliary duct tree as a separate anatomical system
- Pancreatic anatomy and pancreatic disease
- Whole-person symptoms, comorbidities and treatment eligibility
- Medication, device and procedure specifications
Characteristics
- Presence and identification confidence
- present; remnant present; documented removed; congenital absence confirmed; not visualised; uncertain Prevents an unsuccessful observation from being treated as proof that the organ is absent.
- Location and orientation
- Position relative to liver, gallbladder fossa and adjacent structures, with modality and confidence Supports identification and recognition of anatomical variation.
- Cystic duct connection
- Demonstrated connection; suspected connection; surgically altered; unresolved Defines the organ's interface with the biliary system.
- Dimensions and lumen volume
- Dimensions in mm; volume in mL; acquisition method, time and preparation state Allows size and distension to be compared without ignoring differences in examination conditions.
- Wall thickness
- mm, with measurement site, distension state and imaging method Records a wall observation without treating thickness alone as a diagnosis.
- Luminal contents
- Bile-compatible fluid; sludge; calculi; blood suspected; gas; other material; indeterminate Separates different types of contents and preserves uncertainty about their identity.
- Focal wall or luminal lesion
- Absent on examination; present; indeterminate, with site, size, attachment and imaging features Supports comparison of lesions while separating observed appearance from pathological classification.
- Emptying measurement
- Ejection fraction in %, when measured, with test method, stimulus, timing and protocol-specific reference Makes functional measurements interpretable within the protocol that produced them.
- Wall integrity
- No defect detected; suspected defect; demonstrated defect; not assessable Distinguishes evidence of structural disruption from an examination that cannot assess it.
- Intervention status
- No documented intervention; drainage; partial removal; complete removal; other alteration; unknown Explains altered anatomy and determines whether subsequent records concern an intact organ or a remnant.
Also called
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.
Organ identity and boundaries Establishes which structure is the gallbladder and where its ownership ends.
Nonvisualisation, anatomical variation and surgical alteration can otherwise produce incorrect organ identities.
Presence and localisation
Records identification evidence and position.
Identified gallbladder
Captures whether a gallbladder is demonstrated and how its identity was established.
- Which observations identify this structure as the gallbladder, and where is it relative to the liver? definition
- If it is not visualised, what evidence distinguishes examination limitations, contraction, removal and congenital absence? provenance
Neck and duct interface
Defines the organ's connection to neighbouring biliary anatomy.
Cystic duct boundary
Records the observed neck-to-duct transition and any uncertainty or alteration.
- Where does the gallbladder neck transition into the cystic duct in this individual? boundary
- Which imaging or operative evidence establishes that connection and any anatomical variant? provenance
Wall, lumen and contents Describes the gallbladder's physical form and material within its lumen.
Organ size, wall changes and intraluminal material require distinct observations to avoid conflating anatomy with disease.
Shape and wall
Records morphology, distension and wall measurements.
Measured organ form
Captures organ dimensions and wall appearance under stated examination conditions.
- What are the gallbladder dimensions and measured wall thickness, including the sites and methods used? measurement
- What fasting, meal, distension and technical conditions accompanied these measurements? provenance
Contents and focal lesions
Separates mobile contents from attached or wall-based abnormalities.
Material and attachment
Records the features used to distinguish calculi, sludge and focal lesions.
- What material or focal lesion is observed, with what size, number, location and mobility? measurement
- What evidence of attachment, acoustic shadowing or vascularity supports the proposed classification, and what remains indeterminate? provenance
Bile storage and emptying Records filling and emptying observations within their physiological and test context.
A static image cannot by itself establish gallbladder emptying performance or explain an abnormal functional test.
Filling and distension
Captures the observed storage state and evidence of filling.
Observed filling state
Distinguishes anatomical distension from demonstrated filling during a functional examination.
- Is the gallbladder contracted or distended, and is there serial or tracer evidence of filling? measurement
- What preparation, timing and technical limitations affect interpretation of apparent filling or nonfilling? provenance
Stimulated emptying
Records measured response to a specified emptying stimulus.
Protocol-bound emptying result
Preserves the functional result together with the conditions required to interpret it.
- What emptying response or ejection fraction was measured, over what interval and using which stimulus? measurement
- Which protocol-specific reference and documented confounders were used when interpreting the result? provenance
Local abnormalities and integrity Organises evidence of gallbladder disease and structural complications.
An agent must distinguish observed abnormalities, suspected explanations and established diagnoses without attributing every biliary symptom to this organ.
Inflammatory and obstructive evidence
Links local observations to explicitly qualified interpretations.
Qualified local disease assessment
Records evidence supporting or opposing inflammation or impaired outflow at the gallbladder interface.
- Which local observations support or oppose inflammation or impaired gallbladder outflow? provenance
- Which conclusions concern the gallbladder itself, and which require linked duct, liver or whole-person assessments? boundary
Structural disruption and lesion status
Records suspected wall disruption and the evidential classification of focal lesions.
Integrity and pathology evidence
Separates imaging suspicion from operative or pathological confirmation.
- Is wall disruption or a focal lesion suspected or demonstrated, and by which examination or specimen? provenance
- What qualified clinical review or follow-up has been requested for this unresolved finding? action
Interventions and organ continuity Tracks actions that alter the gallbladder and preserves identity across those changes.
Drainage and partial or complete removal change what can subsequently be observed, measured or acted upon.
Planned and performed actions
Records gallbladder-directed actions and the clinical decisions authorising them.
Gallbladder action record
Distinguishes proposed, authorised and completed organ-directed actions.
- What gallbladder-directed action is proposed, authorised or completed, and what clinical decision supports it? action
- What organ-specific anatomy or uncertainty must be resolved before the responsible clinician proceeds? boundary
Residual anatomy and specimens
Links postoperative anatomy and removed tissue to the original organ.
Postintervention organ state
Records what remains and how subsequent observations relate to the preintervention gallbladder.
- Does the intervention record establish an intact gallbladder, a residual gallbladder remnant or complete removal? provenance
- How are any removed specimen, residual gallbladder tissue and cystic duct stump distinguished and linked to the original organ? boundary
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.
- Typical extrahepatic pear-shaped gallbladder
- Phrygian-cap gallbladder (folded fundus)
- Septate or multiseptate gallbladder
- Duplicated gallbladder
- Intrahepatic gallbladder
- Left-sided gallbladder
- Congenital agenesis of the gallbladder
- Floating (wandering) gallbladder on a long mesentery
- Which of these kinds and varieties hold for the sense of gallbladder 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 - Q64386 - Human gallbladder as an anatomical structure
- FMA - 7202 - Foundational Model of Anatomy class Gallbladder
- Terminologia Anatomica - A05.8.02.001 - vesica biliaris / vesica fellea
- UBERON - UBERON:0002110 - Multi-species gallbladder class
- MeSH - D005705 - Heading Gallbladder
- SNOMED CT - 28231008 - Gallbladder structure
- ICD-O topography - C23.9 - Primary site code for gallbladder neoplasms
- Which of these identifiers and schemes hold for the sense of gallbladder 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.
- Terminologia Anatomica - FIPAT / IFAA (anatomical nomenclature of vesica biliaris)
- ICD-10 / ICD-11 - WHO (K80-K82 and successor codes for diseases of the gallbladder)
- SNOMED CT - SNOMED International (structure and disorder concepts)
- Tokyo Guidelines 2018 - Tokyo Guidelines Revision Committee / Japanese Society of Hepato-Biliary-Pancreatic Surgery (diagnosis and severity of acute cholecystitis)
- AJCC / UICC TNM - American Joint Committee on Cancer and Union for International Cancer Control (staging of gallbladder carcinoma)
- SAGES guidelines for laparoscopic cholecystectomy - Society of American Gastrointestinal and Endoscopic Surgeons
- Which of these standards and regulation hold for the sense of gallbladder 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.
- Right-upper-quadrant ultrasound landmark when a patient presents with biliary colic or suspected cholecystitis
- Surgical target of laparoscopic or open cholecystectomy for symptomatic stones or inflammation
- Functional target of hepatobiliary iminodiacetic acid (HIDA) scintigraphy to measure ejection fraction
- Access point for intraoperative cholangiography via the cystic duct
- Resection specimen and staging site in gallbladder carcinoma
- Pathology specimen after cholecystectomy; the organ is not used as a standalone transplant graft
- Which of these real-world use hold for the sense of gallbladder 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.
- Adult length - 7-10 - cm
- Maximum transverse diameter - 2.5-4 - cm
- Fasting luminal volume - 30-50 - mL
- Fasting wall thickness on ultrasound - ≤3 - mm
- CCK-stimulated gallbladder ejection fraction (HIDA) - ≥38-40 (protocol-dependent lower limit of normal) - %
- Which of these typical measurements hold for the sense of gallbladder 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.
- Cholesterol or pigment cholelithiasis with cystic-duct obstruction and biliary colic
- Acute calculous or acalculous cholecystitis, including gangrene, empyema, and perforation
- Chronic cholecystitis and porcelain (wall-calcified) gallbladder
- Gallbladder adenocarcinoma
- Mirizzi syndrome and gallstone ileus from migrated stones
- Iatrogenic bile-duct injury or bile leak at cholecystectomy
- Which of these failure modes and hazards hold for the sense of gallbladder 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.
- British English historically writes 'gall bladder' as two words; Terminologia Anatomica uses both vesica fellea and vesica biliaris
- Cholesterol stones predominate in Western and high-calorie diets; pigment stones are relatively more common in East and South Asia and in chronic hemolysis
- Laparoscopic cholecystectomy is the default in high-resource systems; open cholecystectomy remains more frequent where laparoscopy is unavailable
- East Asian traditional medicine treats 'gallbladder' (dan) as a functional organ-meridian, not identical to the anatomical viscus
- Which of these regional variation hold for the sense of gallbladder 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.
- Common bile duct - Tubular conduit continuous with the hepatic ducts, not a blind pear-shaped reservoir; separated on ultrasound or MRCP by shape and luminal continuity.
- Cystic duct - Narrow connecting channel with spiral valves of Heister, not the bile reservoir itself; distinguished by caliber and lack of a fundus.
- Liver (gallbladder fossa) - Solid vascular parenchyma versus a fluid-filled viscus with a measurable wall.
- Duodenal bulb - Gastrointestinal mucosa continuous with the stomach, not a bile-filled lumen.
- Hepatic flexure of colon - Haustrated, gas- or feces-filled lumen rather than anechoic bile.
- Right kidney - Retroperitoneal organ with a collecting system, lying posterior to the liver rather than in the gallbladder fossa.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of gallbladder this model covers, and on what evidence? provenance
Sources
- Gray's Anatomy: The Anatomical Basis of Clinical Practice - Position in the gallbladder fossa, extrahepatic biliary connections, wall layers, and adult size of the viscus.
- Terminologia Anatomica - Official anatomical name vesica biliaris / vesica fellea and code A05.8.02.001 (FIPAT/IFAA).
- Gallstones - Clinical encounter as the organ that forms and harbours gallstones, and the usual indication for cholecystectomy.
- Gallbladder - Cross-check of identifiers, anatomical variants, wall-thickness threshold on ultrasound, and neighbouring structures.
- Tokyo Guidelines 2018: diagnostic criteria and severity grading of acute cholecystitis (J Hepatobiliary Pancreat Sci) - Practice standard for diagnosing and grading gallbladder inflammation as a failure mode of the organ.
What the second pass must settle
- Does the registry intend this entry to cover human gallbladders only, or multiple species requiring different anatomical and functional references?
- Which examination protocols and population-specific references should govern interpretation of dimensions, wall thickness and emptying measurements?
- What minimum evidence should distinguish nonvisualisation, congenital absence, complete removal and a residual gallbladder remnant?
- Where should ownership of the cystic duct and postoperative stump sit within neighbouring Vercy models?
- Which authoritative clinical sources should define review triggers for gallbladder lesions and suspected complications, and how should their versions be maintained?