endocrine system
Enable an AI agent to recognise an endocrine system, assess the evidence for its regulatory state, and identify justified observations, referrals, or authorised interventions.
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 an endocrine system, assess the evidence for its regulatory state, and identify justified observations, referrals, or authorised interventions.
The endocrine system is the set of ductless glands, dispersed endocrine cells, and circulating hormones that coordinate distant target-cell activity by chemical signalling through the bloodstream (and locally by paracrine/autocrine routes), distinct from neural transmission and from exocrine secretion.
It can be Map documented endocrine tissues, hormones, targets, and feedback relationships for the organism.; Record and contextualise hormone measurements alongside physiological responses.; Compare longitudinal or paired observations within an endocrine axis and flag unexplained discordance.; Identify missing observations needed to distinguish secretion, transport, clearance, and target-response explanations.; Track endocrine effects of documented exposures and authorised interventions.; Route findings for qualified review using applicable protocols while preserving uncertainty and action authority..
Distinguishing features
Determine whether the referent is an organism-level hormone-regulatory system rather than one gland, one hormone, or one endocrine disorder.
Distinguish internal hormone release and target signalling from exocrine delivery through ducts; a mixed-function organ can participate in both.
Identify hormone-producing tissue, a signalling route, and responsive targets; anatomical proximity alone does not establish endocrine participation.
Distinguish endocrine participation from exclusively local paracrine or autocrine signalling, while permitting a molecule or tissue to participate in multiple signalling modes.
Identify endocrine feedback or coordinated regulation rather than treating an isolated hormone concentration as the state of the whole system.
Scope
+ Endocrine glands, distributed endocrine cells, and their participation in hormone signalling
+ Hormone production, secretion, circulation, availability, and clearance
+ Endocrine axes, feedback relationships, and target-tissue responsiveness
+ Temporal regulation and changes associated with development and physiological context
+ Evidence of endocrine function, dysfunction, and effects of interventions
- Whole-organ anatomy and non-endocrine functions owned by individual organ models
- Exocrine secretion through ducts and its digestive or surface functions
- Neural signalling except where it regulates or receives endocrine signals
- Complete reproductive, metabolic, immune, or skeletal systems beyond their endocrine interfaces
- Disease-specific diagnostic criteria and treatment protocols
- Clinical encounter management, prescribing authority, and consent records
Characteristics
- Organism and physiological context
- Species, developmental stage, reproductive context, and relevant physiological conditions Determines which structures, axes, rhythms, and reference comparisons are applicable.
- Endocrine tissue participation
- Tissue or cell population → hormone product → endocrine role; evidence status attached Recognises distributed endocrine activity without equating the system with a fixed list of glands.
- Regulatory connections
- Source, target, signal, stimulatory or inhibitory effect, feedback direction, and supported context Supports interpretation of coordinated and discordant observations across an endocrine axis.
- Hormone concentration
- Analyte-specific units with specimen, collection time, assay, and total or free fraction Makes a measured result interpretable and comparable without confusing concentration with secretion rate.
- Hormone availability and disposition
- Binding, activation, inactivation, and clearance status; measured, inferred, or unknown Separates hormone production from the amount and form available to target tissues.
- Target responsiveness
- Preserved, reduced, increased, mixed, or unknown; qualified by hormone, tissue, and evidence Allows circulating hormone levels and biological response to be assessed separately.
- Secretory timing
- Sampling times, pulse intervals, rhythm phase, amplitude, and observation duration where established Prevents a single sample from being mistaken for sustained endocrine behaviour.
- Axis functional assessment
- Adequate, deficient, excessive, dysregulated, indeterminate, or unassessed; axis and context specified Records a bounded interpretation with uncertainty instead of declaring the entire system normal or abnormal.
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 · 30 questions.
Endocrine membership Establishes which tissues and signalling activities constitute this organism's endocrine system.
The system includes distributed endocrine activity and cannot be recognised solely by naming classical glands.
Organism-specific composition
Locates endocrine participation within the organism and its life stage.
Documented hormone-producing tissues
Record participating glands and cell populations, their hormone products, and the basis for including them.
- Which species and life stage define the endocrine system being modelled? definition
- What evidence establishes hormone production and endocrine participation for each included tissue or cell population? provenance
Signalling boundaries
Separates endocrine roles from adjacent functions without splitting mixed-function organs.
Endocrine role boundary
Record which activities belong to endocrine signalling and which remain owned by neighbouring models.
- For each included signal, what release route and target relationship justify treating it as endocrine? boundary
- Which exocrine, neural, paracrine, or autocrine activities share these tissues but require separate representation? boundary
Hormone availability Represents how hormone production becomes an available signal at a target.
A circulating concentration alone cannot identify whether a difference originates in secretion, binding, conversion, or clearance.
Production and release
Connects hormone products to producing tissues and documented release conditions.
Secretory capacity and drive
Record evidence about hormone production and release, distinguishing direct observations from inferred capacity.
- Which observations support the tissue's ability to produce and release this hormone? provenance
- Which measured stimuli or suppressive conditions accompanied the observed hormone level? measurement
Transport, conversion, and clearance
Tracks processes between release and target exposure.
Available hormone form
Record relevant circulating fractions, molecular forms, and evidence of altered disposition.
- Does the observation measure total hormone, free hormone, a precursor, or a metabolite, and in which specimen? measurement
- What evidence supports a contribution from binding, conversion, or clearance to the observed level? provenance
Axes, feedback, and response Represents coordinated endocrine regulation and the response of target tissues.
Endocrine state depends on relationships among signals and responses, including feedback and sensitivity.
Regulatory axis organisation
Maps upstream regulators, downstream signals, and feedback connections.
Supported feedback relationships
Record the direction, context, and evidential basis of endocrine regulatory connections.
- Which upstream signals, endocrine tissues, downstream hormones, and feedback targets define each represented axis? definition
- Which source supports each stimulatory or inhibitory relationship in this species and physiological context? provenance
Target-tissue response
Connects hormone exposure to tissue sensitivity and observed physiological effects.
Signal-response concordance
Record whether observed target responses align with hormone exposure, preserving alternative explanations.
- Which tissue-specific response measurements accompany the hormone observations, and over what interval? measurement
- What evidence distinguishes altered target responsiveness from altered hormone availability or a non-endocrine cause? provenance
Endocrine observation context Makes endocrine observations interpretable across sampling conditions, rhythms, and physiological transitions.
Sampling time, assay properties, and physiological context can materially change the meaning of an endocrine result.
Sampling and assay interpretation
Captures the conditions and analytical limitations of hormone measurements.
Interpretable hormone observation
Record sufficient analytical and contextual information to judge whether a result supports comparison or inference.
- What specimen, collection time, units, assay method, and relevant collection conditions accompany this result? measurement
- What source supports the chosen reference interval or decision threshold, and does it apply to this organism and context? provenance
- Which documented assay interference or specimen limitation could affect interpretation? measurement
Rhythms and physiological transitions
Places observations within endocrine timing and changes in physiological demand.
Time-dependent endocrine pattern
Record temporal patterns and relevant developmental or physiological transitions without assuming one sample represents a stable state.
- How do sampling times relate to relevant sleep, feeding, pulse, daily, or reproductive timing? measurement
- Which longitudinal observations distinguish a persistent change from a transient response or physiological transition? measurement
Endocrine state and action Connects bounded functional assessments to exposures, review needs, and authorised action.
An agent must distinguish observed endocrine evidence from causal interpretation and from permission to intervene.
Functional state and causal uncertainty
Records axis-specific assessments and competing explanations.
Bounded endocrine assessment
Record the supported functional interpretation, its time window, confidence, and unresolved causes.
- Which paired hormone and physiological observations support the stated functional assessment of this axis? measurement
- What remains unresolved among altered gland function, upstream regulation, hormone disposition, target response, and measurement error? boundary
Exposures and authorised interventions
Tracks endocrine perturbations and the basis for subsequent observation or action.
Endocrine action basis
Record relevant exposures and interventions, their temporal relationship to findings, and the authority and evidence for next steps.
- Which exogenous hormones, medicines, procedures, or other documented exposures preceded the endocrine changes? provenance
- Which applicable protocol and authorised decision-maker determine whether further sampling, dynamic testing, specialist review, or intervention is appropriate? action
- Which endocrine signals and target responses should be followed to assess the outcome of an authorised intervention? 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.
Kinds and varieties
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- classical ductless endocrine glands (pituitary, thyroid, parathyroid, adrenal, pineal)
- hypothalamic neuroendocrine control (releasing and inhibiting hormones, posterior pituitary peptides)
- gonadal endocrine tissue (ovary, testis)
- pancreatic islets (islets of Langerhans)
- diffuse neuroendocrine system / APUD cells (gut, lung, other mucosae)
- adipose and other non-classical endocrine organs (adipokines, myokines, osteokines)
- placental endocrine function (in pregnancy)
- ectopic and tumour-associated hormone production
- Which of these kinds and varieties hold for the sense of endocrine system 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 - Q11078 - item 'endocrine system'
- MeSH - D004703 - descriptor 'Endocrine System'
- UBERON - UBERON:0000949 - anatomical entity 'endocrine system'
- FMA - FMA:9668 - Foundational Model of Anatomy 'Endocrine system'
- ICD-11 - chapter 05 (5A00-5D46 range in MMS) - WHO classification of endocrine, nutritional or metabolic diseases; not an identifier of the healthy system itself
- Which of these identifiers and schemes hold for the sense of endocrine system 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.
- WHO ICD-11 chapter 05 - classification of endocrine, nutritional or metabolic diseases (World Health Organization)
- IUPAC / IFCC recommendations on nomenclature of peptide hormones and immunoassay reporting (International Union of Pure and Applied Chemistry; International Federation of Clinical Chemistry and Laboratory Medicine)
- ISO 15189 - requirements for quality and competence of medical laboratories performing hormone assays (International Organization for Standardization)
- CLIA (US) and IVDR (EU 2017/746) - legal frameworks governing clinical endocrine laboratory testing and in-vitro diagnostic devices (CMS/FDA; European Union)
- Endocrine Society / European Society of Endocrinology clinical practice guidelines - disease-specific standards of care, not a statute (professional societies)
- Which of these standards and regulation hold for the sense of endocrine system 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.
- Clinical endocrinology: diagnosis and long-term management of diabetes, thyroid disease, adrenal failure, pituitary tumours, and reproductive-hormone disorders via blood hormone panels and imaging.
- Pharmacotherapy: replacement (levothyroxine, insulin, hydrocortisone, sex steroids), suppression (antithyroid drugs, somatostatin analogues), and receptor modulation (SERMs, GLP-1 receptor agonists).
- Occupational and environmental health: biomonitoring of endocrine-disrupting chemicals (bisphenols, phthalates, persistent organic pollutants) against hormone-axis endpoints.
- Veterinary and livestock practice: reproductive synchronisation, growth-promoting hormone regulation, and companion-animal endocrine disease (hyperthyroidism, Cushing, diabetes).
- Research and drug development: use of the HPA, HPG and HPT axes as endpoints in toxicology, oncology (hormone-dependent cancers), and metabolic trials.
- Which of these real-world use hold for the sense of endocrine system 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.
- circulating thyrotropin (TSH) - about 0.4-4.0 in many adult reference intervals (method- and lab-specific) - mIU/L
- free thyroxine (FT4) - roughly 9-25 (assay-dependent adult interval) - pmol/L
- morning serum cortisol - approximately 140-690 (clock-time and assay dependent) - nmol/L
- HbA1c (glycated haemoglobin, diabetes/endocrine metabolic control) - non-diabetic typically <42; treatment targets often around 48-53 - mmol/mol (IFCC) or %
- plasma glucose (fasting) - normoglycaemia commonly 3.9-5.6 - mmol/L
- serum 25-hydroxyvitamin D (steroid-hormone metabolite often reported with endocrine panels) - deficiency commonly defined <30; sufficiency often 50-125 - nmol/L
- number of classical endocrine glands commonly enumerated in human anatomy teaching - 8-10 named glands depending on whether pineal, thymus, and gonads are counted - count
- Which of these typical measurements hold for the sense of endocrine system 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.
- Hyposecretion: primary gland failure (Addison disease, primary hypothyroidism, type 1 diabetes, hypogonadism) or secondary/tertiary failure from pituitary or hypothalamic disease.
- Hypersecretion and autonomy: Graves disease, Cushing disease/syndrome, primary hyperparathyroidism, acromegaly, insulinoma and other functioning tumours.
- Receptor or post-receptor resistance: type 2 diabetes, androgen-insensitivity syndromes, thyroid-hormone resistance.
- Iatrogenic disruption: exogenous glucocorticoids, immune-checkpoint inhibitor hypophysitis/thyroiditis, abrupt withdrawal of replacement therapy (adrenal crisis).
- Endocrine-disrupting chemical exposure altering development, fertility, or thyroid economy.
- Oncologic hazard: hormone-dependent cancers (breast, prostate, endometrium) and mass-effect/invasion from pituitary or adrenal tumours.
- Life-threatening acute crises: diabetic ketoacidosis, myxoedema coma, thyroid storm, adrenal crisis, severe hyponatraemia from SIADH or cortisol deficiency.
- Which of these failure modes and hazards hold for the sense of endocrine system 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.
- Iodine nutrition and thyroid disease pattern: iodine-deficient regions still show more goitre and some hyperthyroidism patterns; iodine-replete populations have more autoimmune thyroid disease (WHO/IGN iodine-status maps).
- Diabetes classification and screening thresholds vary slightly across ADA, WHO, and national programmes; gestational-diabetes criteria are not globally uniform.
- Legal status of hormone therapies (gender-affirming hormones, anabolic steroids, growth hormone) differs by jurisdiction.
- Naming: 'endocrine system' vs older 'ductless gland system'; some languages and curricula still treat the pancreas or gonads as primarily exocrine/reproductive rather than endocrine organs.
- Vitamin D cut-offs, units (nmol/L vs ng/mL), and screening policy differ between Endocrine Society, IOM/NAM, and national laboratories.
- Which of these regional variation hold for the sense of endocrine system 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.
- nervous system / neuroendocrine signalling - Neural transmission uses synapses and milliseconds; endocrine signalling uses blood-borne (or tissue-fluid) hormones over seconds to days. Shared hypothalamic neurons that secrete into the portal or systemic circulation are classified as neuroendocrine, not purely neural.
- exocrine system (glands with ducts) - Exocrine products leave via ducts to an epithelial surface (sweat, saliva, pancreatic enzymes, bile); endocrine products enter interstitial fluid and blood. Mixed organs (pancreas, gonads, liver) are separated by which product and route is meant.
- paracrine / autocrine local signalling - Same chemical classes may act locally without a physiologically relevant circulating concentration; endocrine status is assigned when the mediator acts at a distance via blood (or is measured as a circulating hormone in clinical practice).
- immune cytokine network - Cytokines can circulate and affect distant organs, but immunology catalogues them as immune mediators; endocrine catalogues restrict to hormones of dedicated glands and recognised endocrine cells unless a cytokine is used as an endocrine biomarker (e.g. adipokines).
- metabolic / nutritional disease chapter without a primary gland lesion - ICD-11 groups endocrine, nutritional and metabolic diseases together; a primary nutritional deficiency or inborn error of metabolism is not a failure of an endocrine gland even when hormone levels shift secondarily.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of endocrine system this model covers, and on what evidence? provenance
Sources
- Endocrine Glands - Anatomical definition of ductless glands, hormone transport in blood, and the classical gland list (pituitary, thyroid, parathyroid, adrenal, pineal, plus gonads and pancreatic islets as mixed organs).
- Endocrine system - System-level definition, distinction from exocrine glands, hypothalamic control, diffuse neuroendocrine cells, and neighbouring concepts (nervous system, exocrine system).
- ICD-11 - Endocrine, nutritional or metabolic diseases (chapter 05) - Clinical classification of endocrine diseases as a governed diagnostic domain (WHO ICD-11), including gland-specific disease blocks used in practice.
- MeSH - Endocrine System (D004703) - Controlled vocabulary identifier and scope: the system of glands that release chemical substances into the blood, covering glands and circulating hormones as catalogued by NLM.
What the second pass must settle
- Does the registry intend a human endocrine system, vertebrate endocrine systems, or a broader comparative scope requiring different anatomical and signalling structures?
- Which distributed endocrine tissues and signals should be mandatory for recognition, and which should be included only when relevant to the organism or task?
- What evidence standard should establish endocrine participation when the same molecule also acts through paracrine, autocrine, or neural routes?
- Which species-specific sources should govern axis relationships, physiological timing, assay interpretation, and functional assessment?
- Which existing Vercy models own overlapping endocrine concepts, disease protocols, and action authority, and should this entry link to an existing world model?