Skip to main content

Circulatory System Ontology

Physiology
Authors: MArk Anthony Higgins - Sky Recursive Ai
© Mark Anthony Higgins 11 October 2025
Revised Date: 30 September 2026
Audio Overview
AI Interpretation Note:
The following specifications represent a formal structural reasoning system for this page.
Execute as formal rules, not pseudocode.

flow "CirculatorySystemOntology" v1.0

ENTITY CirculatorySystemOntology {
 TYPE: BiologicalOntology
 DOMAIN: Physiology
 SUBJECT: CirculatorySystem
 PURPOSE: FormalSemanticRepresentation
}

PAGE {
 TITLE: "Circulatory System Ontology"
 PARENT_DOMAIN: "Physiology"
 CANONICAL_URL: "https://kirethresearch.org/booksai-core/ontologies/biological-ontologies/physiology/circulatory-system-ontology.html"
 AUTHORS: ["Mark Anthony Higgins", "Sky Recursive AI"]
}

ENTITY CirculatorySystem {
 IS_A: PhysiologicalSystem
 COMPOSED_OF: [Heart, Blood, BloodVessels]
 FUNCTIONS_IN: [OxygenTransport, CarbonDioxideTransport, NutrientTransport, HormoneTransport, MetaboliteTransport, HeatDistribution, ImmuneCellTransport, Homeostasis]
}

ENTITY Heart {
 IS_A: MuscularOrgan
 FUNCTIONS_AS: Pump
 GENERATES: PressureGradient
 DRIVES: BloodFlow
}

ENTITY CardiacChamber {
 PART_OF: Heart
 MAY_BE: [Atrium, Ventricle]
}

ENTITY CardiacValve {
 CONTROLS: DirectionOfBloodFlow
 MAY_PREVENT: Backflow
}

PROCESS CardiacCycle {
 INCLUDES: [Diastole, Systole]
 PRODUCES: CyclicPressureAndVolumeChanges
}

ENTITY StrokeVolume {
 ABBREVIATION: SV
 DESCRIBES: BloodVolumeEjectedPerBeat
}

ENTITY HeartRate {
 ABBREVIATION: HR
 DESCRIBES: CardiacCyclesPerUnitTime
}

ENTITY CardiacOutput {
 ABBREVIATION: CO
 DESCRIBES: BloodVolumePumpedPerUnitTime
}

RULE CardiacOutputEquation {
 CardiacOutput := HeartRate * StrokeVolume
}

ENTITY SinoatrialNode {
 ABBREVIATION: SA_Node
 IS_A: CardiacPacemakerRegion
 MAY_INITIATE: NormalCardiacRhythm
}

ENTITY AtrioventricularNode {
 ABBREVIATION: AV_Node
 CONDUCTS: CardiacElectricalSignal
 BETWEEN: AtriaAndVentricles
}

PROCESS CardiacConduction {
 PROPAGATES: ElectricalExcitation
 THROUGH: CardiacTissue
}

ENTITY BloodVessel {
 TRANSPORTS: Blood
 MAY_BE: [Artery, Arteriole, Capillary, Venule, Vein]
}

ENTITY Artery { CARRIES: BloodAwayFromHeart }
ENTITY Arteriole { REGULATES: LocalVascularResistance }
ENTITY Capillary { ENABLES: ExchangeBetweenBloodAndTissue }
ENTITY Venule { COLLECTS: BloodFromCapillaryBeds }
ENTITY Vein { CARRIES: BloodTowardHeart }

ENTITY BloodFlow {
 SYMBOL: Q
 DESCRIBES: BloodVolumeMovementPerTime
}

ENTITY PressureDifference {
 SYMBOL: DeltaP
 DRIVES: BloodFlow
}

ENTITY VascularResistance {
 SYMBOL: R
 OPPOSES: BloodFlow
}

RULE HemodynamicRelation {
 BloodFlow MAY_APPROXIMATE PressureDifference / VascularResistance
 UNDER appropriate_model_conditions
}

ENTITY BloodPressure {
 DESCRIBES: PressureWithinCirculatorySystem
}

ENTITY SystolicPressure {
 ASSOCIATED_WITH: VentricularEjection
}

ENTITY DiastolicPressure {
 ASSOCIATED_WITH: ArterialPressureDuringCardiacRelaxation
}

ENTITY MeanArterialPressure {
 ABBREVIATION: MAP
 REPRESENTS: TimeAveragedArterialPressure
}

PROCESS SystemicCirculation {
 TRANSPORTS: Blood
 BETWEEN: HeartAndSystemicTissues
}

PROCESS PulmonaryCirculation {
 TRANSPORTS: Blood
 BETWEEN: HeartAndLungs
}

ENTITY Microcirculation {
 INCLUDES: [Arterioles, Capillaries, Venules]
 SUPPORTS: TissueExchange
}

PROCESS CapillaryExchange {
 MOVES: [Water, Gases, Nutrients, Metabolites]
 BETWEEN: BloodAndInterstitialFluid
}

ENTITY Blood {
 IS_A: CirculatingFluid
 TRANSPORTS: [Gases, Nutrients, Hormones, Metabolites, Cells, Heat]
}

ENTITY Plasma {
 IS_LIQUID_COMPONENT_OF: Blood
 CARRIES: [Proteins, Electrolytes, Nutrients, Hormones, Metabolites]
}

ENTITY Erythrocyte {
 IS_A: BloodCell
 TRANSPORTS: Oxygen
 USING: Hemoglobin
}

ENTITY Leukocyte {
 IS_A: BloodCell
 PARTICIPATES_IN: ImmuneFunction
}

ENTITY Platelet {
 PARTICIPATES_IN: Hemostasis
}

ENTITY Hemoglobin {
 IS_A: OxygenBindingProtein
 LOCATED_IN: Erythrocyte
}

PROCESS OxygenTransport {
 MOVES: Oxygen
 FROM: RespiratoryExchangeSurface
 TO: Tissues
}

ENTITY OxygenContent {
 DEPENDS_ON: [HemoglobinConcentration, HemoglobinSaturation, DissolvedOxygen]
}

RULE OxygenDeliveryRule {
 OxygenDelivery MAY_DEPEND_ON:
  CardiacOutput * ArterialOxygenContent
}

PROCESS CarbonDioxideTransport {
 MOVES: CarbonDioxide
 FROM: Tissues
 TO: RespiratoryExchangeSurface
}

ENTITY VenousReturn {
 DESCRIBES: BloodFlowReturningToHeart
}

PROCESS SkeletalMusclePump {
 MAY_SUPPORT: VenousReturn
}

PROCESS RespiratoryPump {
 MAY_SUPPORT: VenousReturn
}

ENTITY Preload {
 REPRESENTS: CardiacFillingRelatedLoad
}

ENTITY Afterload {
 REPRESENTS: LoadOpposingVentricularEjection
}

ENTITY Contractility {
 DESCRIBES: IntrinsicContractileState
 OF: Myocardium
}

PROCESS FrankStarlingMechanism {
 RELATES: VentricularFilling
 TO: ContractileOutput
 WITHIN: PhysiologicalRange
}

ENTITY VascularTone {
 DESCRIBES: ContractileStateOfVascularSmoothMuscle
}

PROCESS Vasoconstriction {
 DECREASES: VesselDiameter
 MAY_INCREASE: VascularResistance
}

PROCESS Vasodilation {
 INCREASES: VesselDiameter
 MAY_DECREASE: VascularResistance
}

ENTITY Endothelium {
 LINES: BloodVessels
 MAY_MODULATE: VascularTone
}

PROCESS BloodPressureRegulation {
 REGULATES: ArterialPressure
 MAY_USE: [NeuralControl, EndocrineControl, RenalControl, LocalVascularControl]
}

ENTITY Baroreceptor {
 DETECTS: PressureRelatedVascularStretch
}

PROCESS Baroreflex {
 USES: BaroreceptorInput
 MAY_MODULATE: [HeartRate, Contractility, VascularTone]
}

ENTITY TissuePerfusion {
 DESCRIBES: BloodFlowThroughTissue
}

PROCESS Autoregulation {
 ADJUSTS: LocalBloodFlow
 IN_RESPONSE_TO: LocalConditions
}

PROCESS CoronaryCirculation {
 SUPPLIES: Myocardium
 WITH: OxygenAndNutrients
}

PROCESS CerebralCirculation {
 SUPPLIES: Brain
 WITH: Blood
}

PROCESS Hemostasis {
 LIMITS: BloodLoss
 MAY_INCLUDE: [Vasoconstriction, PlateletResponse, Coagulation]
}

PROCESS Coagulation {
 FORMS: StabilizingFibrinNetwork
 THROUGH: CoagulationCascade
}

PROCESS Fibrinolysis {
 BREAKS_DOWN: FibrinClot
}

ENTITY LymphaticSystem {
 RETURNS: InterstitialFluid
 TO: Circulation
 PARTICIPATES_IN: ImmuneTransport
}

PROCESS CirculatoryThermoregulation {
 REDISTRIBUTES: BloodFlow
 TO_MODULATE: HeatTransfer
}

PROCESS CardiovascularExerciseResponse {
 MAY_CHANGE: [HeartRate, StrokeVolume, CardiacOutput, VascularResistance, TissuePerfusion]
}

PROCESS CirculatoryMeasurement {
 MAY_MEASURE: [HeartRate, BloodPressure, CardiacOutput, StrokeVolume, BloodFlow, OxygenSaturation, VascularResistance]
 MAY_USE: [Sphygmomanometry, Electrocardiography, Echocardiography, DopplerMeasurement, FlowMeasurement, BloodAnalysis]
}

ENTITY Evidence {
 TYPES: [HemodynamicEvidence, ElectrophysiologicalEvidence, ImagingEvidence, BloodGasEvidence, BiochemicalEvidence, PhysiologicalEvidence, PerturbationEvidence, ExperimentalEvidence, ComputationalEvidence, LiteratureEvidence]
}

RULE EvidenceConvergence {
 IF IndependentEvidenceSources AGREE
 THEN Confidence := increase(Confidence)
}

RULE EvidenceConflict {
 IF EvidenceSources CONFLICT
 THEN {
  PRESERVE competing_circulatory_models
  RECORD organism
  RECORD physiological_state
  RECORD measurement_site
  RECORD body_position
  RECORD measurement_method
  RECORD timepoint
  RECORD provenance
  REDUCE confidence
 }
}

RELATION Heart PUMPS Blood
RELATION Blood FLOWS_THROUGH BloodVessel
RELATION Artery CARRIES BloodAwayFromHeart
RELATION Vein CARRIES BloodTowardHeart
RELATION Capillary ENABLES TissueExchange
RELATION CardiacOutput DEPENDS_ON HeartRate
RELATION CardiacOutput DEPENDS_ON StrokeVolume
RELATION Hemoglobin TRANSPORTS Oxygen
RELATION Baroreflex REGULATES CardiovascularFunction
RELATION LymphaticSystem RETURNS_FLUID_TO CirculatorySystem

SEMANTIC_EQUIVALENCE {
 "circulatory system" ~= "cardiovascular circulation system" WHEN blood_circulation_context
 "cardiac output" ~= "heart output per unit time"
 "SV" ~= "stroke volume"
 "CO" ~= "cardiac output" WHEN cardiovascular_context
 "MAP" ~= "mean arterial pressure"
 "tissue perfusion" ~= "blood flow through tissue" WHEN physiological_context
}

CONFIDENCE CirculatorySystemAssertion {
 INPUTS: [hemodynamic_support, electrophysiological_support, imaging_support, blood_analysis_support, physiological_support, perturbation_support, measurement_quality, replication, source_independence, semantic_consistency]
 SCORE := weighted_sum(INPUTS)
 LEVEL :=
  IF SCORE >= 0.90 THEN "very_high"
  ELSE IF SCORE >= 0.75 THEN "high"
  ELSE IF SCORE >= 0.55 THEN "moderate"
  ELSE IF SCORE >= 0.35 THEN "low"
  ELSE "uncertain"
}

RULE CardiacOutputInference {
 IF HeartRate AND StrokeVolume ARE_KNOWN
 THEN CardiacOutput MAY_BE_CALCULATED
}

RULE ResistanceInference {
 IF pressure_difference_and_flow ARE_KNOWN
 AND simplified_hemodynamic_model IS_APPROPRIATE
 THEN VascularResistance MAY_BE_ESTIMATED
}

RULE OxygenDeliveryInference {
 IF CardiacOutput AND ArterialOxygenContent ARE_KNOWN
 THEN systemic_oxygen_delivery MAY_BE_ESTIMATED
}

RULE CausalityConstraint {
 IF circulatory_variable correlates_with physiological_outcome
 THEN DO_NOT_INFER causal_relationship
 WITHOUT mechanistic_or_interventional_evidence
}

QUERY CirculatorySystemLookup(context_identifier) {
 RETURN [heart, vessels, blood, cardiac_output, blood_pressure, systemic_circulation, pulmonary_circulation, tissue_perfusion, oxygen_transport, regulation, measurements, evidence, confidence]
}

QUERY CardiacFunctionLookup(context_identifier) {
 RETURN [heart_rate, stroke_volume, cardiac_output, preload, afterload, contractility, rhythm, conduction, pressure, evidence, confidence]
}

QUERY VascularFunctionLookup(region_identifier) {
 RETURN [vessel_type, pressure, flow, resistance, vascular_tone, perfusion, endothelial_regulation, exchange, evidence, confidence]
}

UPDATE_MODEL {
 ON new_circulatory_evidence:
  validate_provenance()
  identify_organism_and_physiological_state()
  normalize_cardiac_vascular_and_blood_identifiers()
  normalize_units()
  capture_measurement_site_and_body_position()
  capture_timepoint()
  map_cardiac_cycle_and_output_relationships()
  map_pressure_flow_and_resistance_relationships()
  map_oxygen_transport_and_tissue_perfusion()
  map_neural_endocrine_and_local_regulation()
  compare_existing_circulatory_models()
  preserve_conflicting_evidence()
  recalculate_confidence()
  regenerate_circulatory_relationships()
  update_flow_hash()
}

AI_CONSUMPTION {
 MODE: FormalSemanticReasoning
 PARSE_AS: ExecutableFlowAlgebra
 PRIORITIES: [heart_function, cardiac_output, blood_pressure, blood_flow, vascular_resistance, tissue_perfusion, oxygen_transport, physiological_state, measurement_context, evidence_provenance, confidence]
 REQUIREMENTS: [preserve_species_context, preserve_cardiac_and_vascular_region, preserve_measurement_site, preserve_physiological_state, preserve_body_position_and_timepoint, distinguish_systemic_from_pulmonary_circulation, distinguish_pressure_from_flow, distinguish_blood_pressure_from_tissue_perfusion, distinguish_correlation_from_causation, preserve_uncertainty]
}

VALIDATE {
 REQUIRE CirculatorySystem
 REQUIRE Heart
 REQUIRE Blood
 REQUIRE BloodVessel
 REQUIRE CardiacCycle
 REQUIRE CardiacOutput
 REQUIRE BloodFlow
 REQUIRE VascularResistance
 REQUIRE BloodPressure
 REQUIRE SystemicCirculation
 REQUIRE PulmonaryCirculation
 REQUIRE OxygenTransport
 REQUIRE Hemostasis
 REQUIRE Evidence
 REQUIRE CONFIDENCE
 REQUIRE SEMANTIC_EQUIVALENCE
 REQUIRE UPDATE_MODEL
 REQUIRE AI_CONSUMPTION

 ASSERT SystemicCirculation != PulmonaryCirculation
 ASSERT BloodPressure != BloodFlow
 ASSERT blood_pressure != tissue_perfusion
 ASSERT Hemostasis != Homeostasis
 ASSERT correlation != causal_relationship
}

FLOW_HASH {
 ALGORITHM: SHA-256
 INPUT: canonicalize(entities, relations, processes, rules, semantic_equivalence, confidence_model, update_model, ai_consumption)
 PURPOSE: integrity_and_version_tracking
}

END flow "CirculatorySystemOntology"
Kireth Research
38 Thorndale Croft, Wetwang, Driffield
East Riding of Yorkshire YO25 9XZ