duodenum
Enable an AI agent to recognise a duodenum, record its anatomical and functional state, and identify what further evidence or authorised assessment is needed.
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.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an AI agent to recognise a duodenum, record its anatomical and functional state, and identify what further evidence or authorised assessment is needed.
The duodenum is the first segment of the small intestine, extending from the pylorus of the stomach to the duodenojejunal junction, where gastric contents mix with bile and pancreatic secretions for digestion.
It can be Locate and annotate duodenal segments on anatomical records, images or examination reports.; Attach endoscopic observations and biopsy results to their actual sampling sites.; Map connections to the stomach, jejunum and pancreatic or biliary ducts.; Compare local measurements over time when methods and conditions are compatible.; Flag missing evidence or findings requiring qualified clinical assessment.; Record how an authorised intervention changed duodenal anatomy or passage..
Distinguishing features
Identify the small-intestinal segment immediately downstream of the pylorus and upstream of the jejunum; proximity to the stomach alone is insufficient.
In typical human anatomy, trace superior, descending, horizontal and ascending parts, with the course closely related to the pancreatic head.
Look for the major duodenal papilla in the descending part as a characteristic duct-entry landmark, recording variants or altered anatomy.
On suitable histological material, submucosal Brunner glands support duodenal identification; villi alone do not distinguish it from other small-intestinal segments.
Scope
+ Boundaries from the gastric pylorus to the duodenojejunal junction
+ Duodenal subdivisions, wall organisation and luminal configuration
+ Interfaces with pancreatic and biliary drainage
+ Local contributions to digestion, acid neutralisation and nutrient absorption
+ Segment-specific observations, abnormalities and effects of interventions
- The stomach, jejunum and remaining intestinal tract as independently modelled structures
- The pancreas, liver, gallbladder and their complete duct systems
- Whole-body digestion, nutrition and metabolic status
- Diseases as independent diagnostic entities
- Endoscopes, imaging systems and surgical procedures as independent things
Characteristics
- Organism and life stage
- Host organism reference, species and life stage Anatomical expectations and interpretation of dimensions depend on the organism and developmental context.
- Anatomical extent represented
- Whole duodenum; superior, descending, horizontal or ascending part; bulb; unspecified fragment An observation from one segment or biopsy cannot automatically describe the whole organ.
- Boundary continuity
- Connections to pylorus and jejunum, or documented reconstructed connections Connections establish identity and explain the route of luminal contents.
- Segment dimensions
- Length in cm; luminal diameter and wall thickness in mm, with site, method and distension context Dimensions support assessment of configuration, dilation or narrowing only when measurement conditions are known.
- Luminal patency
- Patent; narrowed; obstructed; indeterminate, with location and evidence Patency affects passage from the stomach into the downstream small intestine.
- Mucosal and wall condition
- Observed surface, villous architecture and wall findings, with examination modality and sampling location Surface inspection, histology and imaging describe different aspects of tissue condition.
- Duct-entry configuration
- Observed papillae and their biliary or pancreatic connections; variant, altered or unknown configuration These interfaces explain secretion delivery and provide landmarks for local assessment.
- Luminal acidity
- pH, with segment, time, feeding state and measurement method Acidity helps characterise the local environment without assuming that one reading represents overall neutralisation.
- Anatomical alteration
- Native; congenital variant; surgically altered; partially resected; unknown, with description Alterations can change expected landmarks, continuity and the interpretation of observations.
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 5 bundles · 9 layers · 14 findings · 22 questions.
Duodenal identity and boundaries Establish which anatomical structure and portion the record represents.
Duodenal observations require reliable distinction from gastric, jejunal and surgically reconstructed anatomy.
Host and anatomical reference
Anchor the structure to its organism and applicable anatomical vocabulary.
Duodenal reference context
Record species, life stage and whether the anatomy follows the selected reference description.
- Which organism, species and life stage does this duodenum belong to? provenance
- Is the human four-part description applicable, or does this organism require a different subdivision scheme? definition
Proximal, distal and segment limits
Identify continuity and the precise extent covered by observations.
Pylorus-to-jejunum extent
Locate the proximal and distal limits and distinguish a complete duodenum from a segment or tissue sample.
- What landmarks establish the pyloric boundary and duodenojejunal junction in this record? boundary
- Does the evidence cover the entire duodenum, a named part, the bulb or only an incompletely localised fragment? boundary
Duodenal course and wall Represent the course, lumen and tissue features used to identify and assess the duodenum.
Duodenal geometry and wall organisation affect passage and determine what different examinations can establish.
Course and luminal geometry
Describe segment position, relationships and calibre.
Segment course and calibre
Record the observed course relative to the pancreatic head and local dimensions without imposing an unsupported normal range.
- How do the observed duodenal segments course relative to the pancreatic head and neighbouring structures? boundary
- What segment lengths, luminal diameters or focal narrowings were measured, and under what distension and imaging conditions? measurement
Mucosa and wall organisation
Separate mucosal architecture from deeper wall findings.
Duodenal tissue evidence
Capture villous and crypt architecture, Brunner glands where sampled, and deeper wall observations with their evidential limits.
- Which villous, crypt or Brunner-gland features are actually demonstrated, and does the sample include the tissue depth needed to assess them? measurement
- Which segment and examination or specimen produced each wall finding? provenance
Duodenal digestive interfaces Represent incoming gastric contents, secretion entry and the local digestive environment.
The duodenum connects gastric delivery with pancreatic and biliary inputs, making these interfaces central to its functional identity.
Pancreatic and biliary entry
Locate papillae and record demonstrated duct connections.
Papillae and duct connections
Describe the major papilla and any identified minor papilla or variant openings without assuming unseen connections.
- Where are the major papilla and any minor or variant openings located? boundary
- Which pancreatic or biliary connections are demonstrated, and by which examination? provenance
Gastric delivery and local processing
Capture evidence about passage, acidity and local digestive or absorptive function.
Duodenal processing evidence
Separate direct local measurements from broader inferences about digestion and absorption.
- What observations establish passage of gastric contents through the duodenum, and under what feeding or examination conditions? measurement
- What local evidence supports an assessment of acid neutralisation, digestion or absorption, and which conclusions remain indirect? measurement
Duodenal condition and alteration Record local abnormalities, uncertainty and changes caused by interventions.
An agent must distinguish observed duodenal changes from diagnoses and account for anatomy that no longer follows the native arrangement.
Local abnormalities and evidence
Localise abnormalities and preserve the limits of each assessment.
Duodenal abnormality localisation
Record findings such as ulceration, bleeding, narrowing, dilation or a suspected wall defect at a specified duodenal site.
- What abnormality is observed, in which duodenal part, and with what measured extent? measurement
- Which examination supports the finding, and is it an observation, a suspected interpretation or an established diagnosis? provenance
Altered anatomy and follow-up
Track reconstructed continuity and the evidence needed for further assessment.
Duodenal intervention consequences
Record resections, bypasses or other alterations and their consequences for landmarks, contents and secretion routes.
- Which duodenal portions and connections remain, and how do contents and secretions reach or bypass them? boundary
- What further assessment has a qualified clinician requested or authorised to resolve the recorded uncertainty? action
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.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- This description assumes normal human anatomy; other vertebrates also have a duodenum, with species-dependent anatomy.
- Adult length is approximate and varies with the individual and measurement method.
- Recalled knowledge only; no sources were consulted, and no numerical anatomical identifier is asserted.
- Which of these check these first hold for the sense of duodenum this model covers, and on what evidence? provenance
Identifiers and schemes
Recalled without web access and unsourced; every item is a lead to verify.
- Terminologia Anatomica - duodenum - Standard Latin anatomical name; its four named parts are subdivisions, not separate kinds.
- Which of these identifiers and schemes hold for the sense of duodenum this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Receives gastric contents and helps neutralize their acidity through bicarbonate-rich secretions.
- Mixes food with pancreatic enzymes and bile to support digestion.
- Absorbs nutrients, including an important share of dietary iron and calcium.
- Participates in regulating digestion through hormones including secretin and cholecystokinin.
- Provides biopsy tissue for investigating disorders such as coeliac disease.
- Which of these real-world use hold for the sense of duodenum this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Length in adult humans - Approximately 20-30 - cm
- Which of these typical measurements hold for the sense of duodenum this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Peptic ulceration can cause bleeding, perforation or narrowing.
- Congenital atresia or stenosis can obstruct intestinal passage.
- Coeliac disease can damage the mucosa and impair nutrient absorption.
- External compression, including in superior mesenteric artery syndrome, can obstruct the third part.
- Traumatic injury can cause leakage into retroperitoneal tissues and may be difficult to detect promptly.
- Which of these failure modes and hazards hold for the sense of duodenum this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- stomach - The stomach lies upstream of the pylorus; the duodenum begins on its intestinal side.
- jejunum - The jejunum begins at the duodenojejunal junction; submucosal Brunner glands characteristically distinguish duodenal tissue.
- small intestine - The small intestine is the whole organ segment comprising duodenum, jejunum and ileum; the duodenum is its proximal subdivision.
- pancreas - The pancreas is a gland whose exocrine secretions enter the duodenum through ducts; the duodenum is the intestinal passage receiving them.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of duodenum this model covers, and on what evidence? provenance
What the second pass must settle
- Does the registry intend a human-specific model or a cross-species duodenum model, and which subdivision vocabulary should govern nonhuman records?
- Which authoritative anatomical references should define segment boundaries and accepted duct-entry variants?
- Which reference ranges for dimensions and wall thickness are defensible for each age group, modality and distension condition?
- How should local measurements support claims about duodenal neutralisation or absorption without attributing whole-system function to this segment alone?
- How should the model link to existing small-intestine, tissue, disease and procedure models, especially when surgery removes or bypasses the duodenum?