{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.perineurium","code":"thing-q2393792","url":"https://ver.cy/models/thing/q2393792/","name":"perineurium","alternateNames":[],"kind":"thing","status":"published","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Physical world and living systems","entryKind":"thing","plane":"PHY","domain":["PHY.LIV"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"The perineurium is a specialized multilamellar sheath of flattened perineurial cells, basal laminae and extracellular matrix that surrounds individual peripheral nerve fascicles, provides mechanical support and forms a selective barrier around the endoneurial compartment.","purpose":"Enable an agent to recognize perineurium, assess its fascicle-enclosing structure and barrier state, and identify what evidence is needed before sampling or intervention.","scope":{"in":["Perineurial enclosure of an identified nerve fascicle and its anatomical continuity","Perineurial cells, lamellae, junctions and associated extracellular matrix","Transport across the perineurial boundary and evidence of barrier integrity","Local deformation, disruption, remodeling and repair of the sheath","Evidence required to distinguish perineurium from adjacent nerve compartments"],"out":["Whole-organism taxonomy, conservation status and population biology","Whole-nerve organization and conduction performance","Epineurial connective tissue surrounding and separating fascicles","Endoneurial tissue and its microvascular endothelial barrier","Axons, Schwann cells and myelin as independently modeled structures","Diagnosis and treatment of neuropathies or perineurial tumors as complete clinical entities"],"boundaries":[]},"distinguishingFeatures":["Identify a sheath enclosing a nerve fascicle, rather than connective tissue distributed among individual nerve fibers.","Distinguish the organized perineurial cellular boundary from the surrounding epineurial connective tissue.","Look for concentric flattened cellular layers and junctional evidence; tightly joined perineurial layers were examined directly in [an ultrastructural study](https://pubmed.ncbi.nlm.nih.gov/12712870/).","Distinguish a fascicle-enclosing sheath from myelin associated with an individual axon-Schwann cell unit.","Locate the barrier being assessed: a fascicular sheath and the lining of an endoneurial blood vessel are different anatomical structures."],"structure":{"bundles":[{"id":"fascicular-identity","name":"Fascicular identity","description":"Establish which fascicular sheath is being modeled and where its boundaries lie.","layers":[{"id":"anatomical-localization","name":"Anatomical localization","description":"Anchor the sheath to a particular nerve segment and fascicle.","findings":[{"id":"enclosed-fascicle","name":"Enclosed fascicle","description":"Record the fascicle enclosed by the candidate sheath and the anatomical extent actually observed.","questions":[{"text":"Which species, nerve, segment and fascicle does this perineurium belong to?","id":"enclosed-fascicle-q01","kind":"provenance"},{"text":"What demonstrates that the candidate boundary encloses a fascicle rather than the entire nerve or an individual fiber?","id":"enclosed-fascicle-q02","kind":"boundary"}]}]},{"id":"adjacent-compartments","name":"Adjacent compartments","description":"Resolve the inner and outer interfaces and distinguish tissue from constituent cells.","findings":[{"id":"sheath-compartment-boundaries","name":"Sheath and compartment boundaries","description":"Identify the perineurial tissue boundary separately from epineurium, endoneurium and isolated perineurial cells.","questions":[{"text":"Where do the inner and outer perineurial surfaces lie in this preparation?","id":"sheath-compartment-boundaries-q01","kind":"boundary"},{"text":"Does the observation concern a native sheath, a fragment of it or cells identified as perineurial?","id":"sheath-compartment-boundaries-q02","kind":"definition"}]}]}]},{"id":"lamellar-architecture","name":"Lamellar architecture","description":"Describe the cellular and matrix organization that forms the fascicular enclosure.","layers":[{"id":"cellular-layering","name":"Cellular layering","description":"Resolve perineurial lamellae and their geometry.","findings":[{"id":"lamellar-geometry","name":"Lamellar geometry","description":"Measure local sheath thickness and resolved layer count without assigning an unsupported normal range.","questions":[{"text":"How many cellular lamellae are resolved at each sampled location?","id":"lamellar-geometry-q01","kind":"measurement"},{"text":"What is the sheath thickness, and how were oblique sections and tissue shrinkage addressed?","id":"lamellar-geometry-q02","kind":"measurement"}]}]},{"id":"junctions-and-matrix","name":"Junctions and matrix","description":"Assess cell contacts and the matrix associated with the sheath.","findings":[{"id":"structural-sealing-evidence","name":"Structural sealing evidence","description":"Record observed cell junctions, basal laminae and matrix organization separately from conclusions about permeability.","questions":[{"text":"Which cell contacts and associated basal laminae can the chosen method actually resolve?","id":"structural-sealing-evidence-q01","kind":"measurement"},{"text":"What evidence supports perineurial cell identity rather than identification from position alone?","id":"structural-sealing-evidence-q02","kind":"provenance"},{"text":"Which apparent gaps could result from sectioning, fixation or limited resolution?","id":"structural-sealing-evidence-q03","kind":"boundary"}]}]}]},{"id":"perineurial-barrier","name":"Perineurial barrier","description":"Evaluate passage across the fascicular sheath under explicitly defined conditions.","layers":[{"id":"transport-assessment","name":"Transport assessment","description":"Define the probe, route and experimental conditions for permeability observations.","findings":[{"id":"probe-specific-passage","name":"Probe-specific passage","description":"Represent permeability as an observation for a named substance, exposure and direction rather than a universal sealed-or-open property.","questions":[{"text":"Which substance was tested, at what concentration, for how long and in which direction across the sheath?","id":"probe-specific-passage-q01","kind":"measurement"},{"text":"Was passage measured quantitatively or inferred from tracer localization?","id":"probe-specific-passage-q02","kind":"measurement"},{"text":"What control excludes entry through exposed ends or preparation-induced breaches?","id":"probe-specific-passage-q03","kind":"boundary"}]}]},{"id":"barrier-attribution","name":"Barrier attribution","description":"Separate the perineurial boundary from endoneurial vascular barriers.","findings":[{"id":"sheath-versus-vessel-route","name":"Sheath versus vessel route","description":"Require route-specific evidence before attributing endoneurial tracer entry to perineurium; these routes showed different permeability behavior in [a nerve-grafting experiment](https://pubmed.ncbi.nlm.nih.gov/537675/).","questions":[{"text":"What distinguishes passage across the sheath from leakage through endoneurial vessels?","id":"sheath-versus-vessel-route-q01","kind":"boundary"},{"text":"Does the experiment measure perineurial function specifically or a combined nerve-barrier outcome?","id":"sheath-versus-vessel-route-q02","kind":"definition"}]}]}]},{"id":"integrity-and-remodeling","name":"Integrity and remodeling","description":"Track local mechanical changes, structural damage and subsequent sheath reorganization.","layers":[{"id":"local-damage","name":"Local damage","description":"Locate discontinuities and relate deformation to documented exposures.","findings":[{"id":"breach-and-deformation","name":"Breach and deformation","description":"Record the position and extent of sheath alteration while separating observation from its proposed cause.","questions":[{"text":"Where is the sheath disrupted, separated or deformed, and over what measured extent?","id":"breach-and-deformation-q01","kind":"measurement"},{"text":"What evidence links the alteration to loading, injury or disease rather than specimen handling?","id":"breach-and-deformation-q02","kind":"provenance"}]}]},{"id":"repair-trajectory","name":"Repair trajectory","description":"Compare structural re-enclosure and barrier recovery over time.","findings":[{"id":"structural-and-functional-recovery","name":"Structural and functional recovery","description":"Treat restored enclosure and restored permeability control as separate outcomes; compartment formation and persistent tracer permeability coexisted in [experimental nerve grafts](https://pubmed.ncbi.nlm.nih.gov/537675/).","questions":[{"text":"What evidence shows continuity or lamellar reorganization at each observed time point?","id":"structural-and-functional-recovery-q01","kind":"measurement"},{"text":"Was barrier function tested independently of the appearance of structural repair?","id":"structural-and-functional-recovery-q02","kind":"measurement"},{"text":"Which species, injury model and follow-up interval limit application of this repair evidence?","id":"structural-and-functional-recovery-q03","kind":"provenance"}]}]}]},{"id":"assessment-and-manipulation","name":"Assessment and manipulation","description":"Connect the evidence available about a sheath to justified assessment and intervention decisions.","layers":[{"id":"specimen-interpretation","name":"Specimen interpretation","description":"Determine what a particular preparation can establish about native perineurium.","findings":[{"id":"assessment-adequacy","name":"Assessment adequacy","description":"Match imaging, section sampling and functional assays to the specific perineurial property under assessment.","questions":[{"text":"Can this preparation resolve the lamellae, junctions or discontinuity relevant to the question?","id":"assessment-adequacy-q01","kind":"measurement"},{"text":"How much of the fascicular circumference and longitudinal extent was examined?","id":"assessment-adequacy-q02","kind":"measurement"},{"text":"What additional evidence is required before generalizing this observation to the intact sheath?","id":"assessment-adequacy-q03","kind":"action"}]}]},{"id":"boundary-crossing-actions","name":"Boundary-crossing actions","description":"Locate proposed sampling or manipulation relative to the perineurial enclosure.","findings":[{"id":"manipulation-footprint","name":"Manipulation footprint","description":"Specify whether an action remains outside the sheath, contacts it or breaches it, and how the resulting change would be assessed.","questions":[{"text":"Would the proposed action contact, remove or cross the perineurium of an identified fascicle?","id":"manipulation-footprint-q01","kind":"boundary"},{"text":"What procedure-specific evidence and qualified judgment are required before proceeding?","id":"manipulation-footprint-q02","kind":"action"},{"text":"How would the location and extent of any resulting sheath disruption be documented?","id":"manipulation-footprint-q03","kind":"action"}]}]}]},{"id":"evidence-and-external-alignment","name":"Evidence and external alignment","description":"What the world already says about this thing, gathered so the model can be checked against it.","layers":[{"id":"reported-evidence","name":"Reported evidence","description":"Findings from the breadth pass, kept separate from the structural claims.","findings":[{"id":"evidence-confidence-notes","name":"Check these first","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these check these first hold for the sense of perineurium this model covers, and on what evidence?","id":"evidence-confidence-notes-q01","kind":"provenance"}]},{"id":"evidence-identifiers","name":"Identifiers and schemes","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these identifiers and schemes hold for the sense of perineurium this model covers, and on what evidence?","id":"evidence-identifiers-q01","kind":"provenance"}]},{"id":"evidence-real-world-use","name":"Real-world use","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these real-world use hold for the sense of perineurium this model covers, and on what evidence?","id":"evidence-real-world-use-q01","kind":"provenance"}]},{"id":"evidence-failure-modes-and-hazards","name":"Failure modes and hazards","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these failure modes and hazards hold for the sense of perineurium this model covers, and on what evidence?","id":"evidence-failure-modes-and-hazards-q01","kind":"provenance"}]},{"id":"evidence-neighbours","name":"Neighbouring kinds and how to tell them apart","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these neighbouring kinds and how to tell them apart hold for the sense of perineurium this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Describe the perineurium's structure and barrier function from anatomical and research literature.","Annotate or measure perineurial layers in histological images for lawful research or teaching."],"mustNot":["Give surgical or injection guidance for working on or through a nerve sheath.","Interpret a person's nerve biopsy or imaging as a diagnosis.","Use human nerve tissue or images without ethical approval and donor consent.","Present animal findings about nerve barriers as established in people."],"requiresHuman":["Any clinical interpretation or procedure involving a patient's nerves.","Approving research use of human nerve tissue."]},"ethics":{"considerations":["Nerve injury causes lasting pain and disability, so clinical caution matters.","Human tissue and biopsy images carry donor consent conditions and patient privacy."],"affectedParties":["Patients with nerve injury or disease","Tissue donors and their families","Research animals"]},"owners":{"steward":"The clinician or researcher responsible for the tissue, under the institution's ethics approval.","roles":[],"masterSystems":["Institutional biobank and ethics approval records"]},"relations":[{"target":"Q112826975","type":"parent","note":"registry parent class"},{"target":"Q6036578","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.perineurium","Wikidata: Q2393792 (https://www.wikidata.org/wiki/Q2393792)"]},"properties":{"applicability":"required","items":["Anatomical attachment: Species, individual or specimen, named nerve, side, segment and enclosed fascicle","Boundary continuity: Continuous in sampled extent; discontinuous; indeterminate; include sampled length or circumference","Sheath thickness: µm, with sampling positions, section orientation and preparation method","Lamellar count: Number of resolved cellular layers at specified positions","Junctional evidence: Ultrastructurally demonstrated; molecularly supported; unresolved; not assessed","Perineurial permeability: Assay-defined permeability coefficient, such as cm/s, or tracer passage with concentration, time and direction","Local deformation: Strain (%) or displacement (µm), with loading direction, rate and boundary conditions","Observed alteration: No alteration detected by stated method; thickening; separation; breach; remodeling; indeterminate","Observation context: In vivo; fresh ex vivo; fixed tissue; cultured cells; reconstructed experimental system"]},"recognition":{"applicability":"required","items":["In a transverse histological section, it forms a distinct boundary around an individual nerve fascicle.","At sufficient microscopic resolution, its flattened cells form concentric layers around the enclosed nerve fibers.","It is more organized into a fascicular sheath than the delicate endoneurial connective tissue between individual nerve fibers.","It lies inside the broader epineurial connective tissue that surrounds and separates fascicles."]},"capabilities":{"applicability":"required","items":["Annotate the perineurial boundary and link it to the enclosed fascicle.","Quantify thickness, lamellar organization and discontinuities using a documented sampling method.","Evaluate tracer passage while separating perineurial transport from vascular leakage and cut-edge artifacts.","Compare local sheath changes across matched anatomical sites or experimental time points.","Identify which fascicular boundary a proposed sampling or manipulation would cross.","Flag unsupported interpretations and specify the additional imaging or functional evidence required."]},"hazards":{"applicability":"required","items":["Damage to the perineurial barrier can disturb the protected environment of nerve fibers and impair nerve function.","Scarring or pathological thickening can accompany nerve injury and altered fascicular mechanics.","Misidentification of the sheath during sampling or intervention can contribute to unintended nerve injury."]},"interfaces":{"applicability":"required","items":["Terminologia Anatomica, issued by the Federative International Programme for Anatomical Terminology, provides standardized anatomical nomenclature that includes the perineurium."]},"context":{"applicability":"required","items":["The perineurium surrounds individual fascicles within peripheral nerves and helps maintain their internal environment.","It is examined in anatomy, histology and nerve pathology to understand fascicle organization and barrier integrity."]}},"sources":[{"title":"Wikidata item Q2393792: perineurium","url":"https://www.wikidata.org/wiki/Q2393792","note":"identity and sense of the item"},{"title":"Wikipedia: Perineurium","url":"https://en.wikipedia.org/wiki/Perineurium","note":"general description of the item"}],"openQuestions":["What reference ranges for thickness and lamellar count are defensible for particular species, ages, nerve segments and fascicle sizes?","Which combinations of morphology and molecular markers reliably identify perineurial cells in normal, injured and diseased specimens?","How should this registry entry relate to specialized perineurial continuations or perineurial-like layers at nerve roots, terminals and sensory corpuscles?","Which permeability assays and thresholds predict meaningful loss of perineurial barrier function in each intended use context?","What evidence establishes functional recovery after sheath repair, and how transferable are experimental injury findings to human peripheral nerves?"],"resources":{"spec":"/models/things/publications/thing-q2393792/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q2393792/spec.json"],"providers":["Codex"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T12:00:51Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"filled","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-09T07:30:01+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass"},"score":1.0}}