Muscular System Ontology

FLOW ALGEBRA
MUSCULAR SYSTEM ONTOLOGY
Version: 1.1
Source URL: https://kirethresearch.org/booksai-core/entity-graph/physical-entities/human-entities/muscular-system-ontology.html
Authors: Mark Higgins — Sky (Recursive AI)
Publisher: Kireth Research | https://kirethresearch.org
Status: Independent scientific synthesis; source page not independently verified.

01. PURPOSE
Represent human muscular-system anatomy, physiology, mechanics, regulation and evidence with typed, checkable relations.

02. SCOPE
Includes skeletal, cardiac and smooth muscle; their cells, tissues, attachments, functions and interactions. Distinguish muscular system in locomotor anatomy from the broader set of all muscle tissues.

03. CORE TYPES
Entity := PhysicalEntity | BiologicalEntity | Process | Quantity | Observation | Model.
MuscleTissue <: Tissue.
MuscleCell <: Cell.
SkeletalMuscle <: Organ.
CardiacMuscleTissue <: MuscleTissue.
SmoothMuscleTissue <: MuscleTissue.
SkeletalMuscleTissue <: MuscleTissue.
Tendon <: ConnectiveTissue.
MotorNeuron <: Neuron.
MotorUnit := (MotorNeuron, Set[MuscleFibre]).
Joint <: AnatomicalStructure.

04. TYPE RESTRICTIONS
partOf: AnatomicalEntity x AnatomicalEntity -> Boolean.
innervates: Neuron x AnatomicalEntity -> Boolean.
attachesTo: Tendon x Bone -> Boolean.
contracts: MuscleTissue x TimeInterval -> Boolean.
producesForce: Muscle x Quantity[Newton] -> Boolean.
measuredBy: Quantity x MeasurementMethod -> Boolean.
Do not infer a muscle's innervation from adjacency alone.

05. MUSCLE CATEGORIES
Skeletal: striated, usually voluntary somatic control.
Cardiac: striated, intrinsic pacemaking and autonomic modulation.
Smooth: non-striated, generally involuntary visceral and vascular function.
Exceptions and physiological context must be retained.

06. SKELETAL MUSCLE ORGANISATION
Muscle -> fascicle -> muscle fibre -> myofibril -> sarcomere.
Sarcomere contains thin (actin) and thick (myosin) filaments.
Epimysium, perimysium and endomysium are connective-tissue layers.

07. CONTRACTILE MECHANISM
Excitation -> calcium release -> cross-bridge cycling -> force generation.
ATP is required for myosin cycling and calcium handling.
Sliding filament action changes filament overlap, not filament length.

08. NEUROMUSCULAR JUNCTION
Motor neuron action potential -> acetylcholine release -> endplate depolarisation -> muscle action potential.
Acetylcholinesterase contributes to signal termination.

09. EXCITATION-CONTRACTION COUPLING
Muscle action potential -> transverse tubules -> sarcoplasmic-reticulum calcium release.
Calcium binds troponin in skeletal and cardiac muscle; smooth muscle uses calmodulin-dependent regulation.

10. MUSCLE FIBRE PROPERTIES
Fibre properties vary continuously in oxidative capacity, myosin isoform, fatigue resistance and contraction speed.
Human skeletal muscle is commonly described using Type I and Type II subtypes; classifications depend on method.

11. MUSCLE ARCHITECTURE
Fascicle length, pennation angle and physiological cross-sectional area influence force and excursion.
Muscle force is not identical to tendon force in all dynamic conditions.

12. MECHANICAL QUANTITIES
Force F: N; length L: m; velocity v: m/s; torque tau: N m; power P: W.
Stress sigma = F/A (Pa), when force and area are appropriately defined.
Strain epsilon = (L-L0)/L0, dimensionless.

13. JOINT TORQUE
For a specified axis, tau = r x F; magnitude tau = r F sin(theta).
Net joint torque sums muscle, passive and external contributions.

14. MECHANICAL POWER
Instantaneous translational power P = F dot v.
Rotational power P = tau dot omega.
Signs depend on coordinate convention and whether work is generated or absorbed.

15. FORCE-LENGTH RELATION
Active tension depends on actin-myosin overlap and activation.
Passive tension can increase with stretch.
Relations are model-dependent and differ among muscle types.

16. FORCE-VELOCITY RELATION
Concentric shortening generally reduces maximum force as shortening speed rises.
Eccentric force behaviour is distinct; simple Hill fits are approximations.

17. ACTIVATION AND RECRUITMENT
Neural drive changes motor-unit recruitment and firing rates.
Observed surface EMG amplitude is not a direct universal measure of muscle force.

18. ENERGETICS
ATP replenishment involves phosphagen, glycolytic and oxidative pathways.
Dominant pathway depends on intensity, duration and physiological state.

19. FATIGUE
Fatigue is a task-dependent decline in capacity to generate force or power.
Central and peripheral mechanisms can contribute; no single marker is sufficient.

20. ADAPTATION
Loading can change muscle size, strength, neural coordination and tendon properties.
Adaptation depends on exposure, recovery, nutrition and individual factors.

21. CARDIAC MUSCLE
Cardiomyocytes form electrically coupled networks via intercalated discs.
Cardiac contractility is regulated by calcium handling and physiological loading.
Do not equate cardiac muscle control with skeletal voluntary activation.

22. SMOOTH MUSCLE
Smooth muscle occurs in vessels, airways, gastrointestinal and other organs.
Contraction depends on calcium-calmodulin and myosin light-chain regulation.
Its mechanical and activation models differ from skeletal muscle.

23. MUSCLE DEVELOPMENT
Myogenesis involves precursor specification, differentiation and fusion for skeletal muscle.
Developmental origin and repair potential vary among muscle types.

24. REPAIR AND REMODELLING
Satellite cells support skeletal muscle regeneration; fibrosis may limit functional recovery.
Cardiac repair is constrained relative to skeletal muscle.

25. BLOOD SUPPLY
Perfusion supplies oxygen and substrates and removes metabolites.
Flow depends on tissue, activation and vascular regulation.

26. SENSORY FEEDBACK
Muscle spindles detect length-related changes; Golgi tendon organs respond to tension-related stimuli.
Spinal and supraspinal circuits integrate feedback.

27. POSTURE AND MOVEMENT
Muscles act across joints in coordinated agonist, antagonist and synergist roles.
These roles depend on the task and mechanical configuration.

28. MUSCULOSKELETAL INTERFACE
Muscle -> tendon -> bone -> joint motion is a useful simplified chain.
Multiarticular muscles, fascia and passive tissues complicate transmission.

29. EQUILIBRIUM
Static equilibrium requires sum(F)=0 and sum(tau)=0 for the selected body or segment.
Dynamic analysis uses mass and inertia and explicitly specified frames.

30. MUSCLE MODEL
A simplified Hill-type actuator combines active contractile, series-elastic and parallel-elastic elements.
Parameters require calibration; model output is not direct clinical evidence.

31. STATE MODEL
MuscleState := {activation, fibreLength, fibreVelocity, force, fatigueState, temperature, timestamp}.
Each quantity must include units, reference frame and measurement uncertainty where relevant.

32. PROCESS FLOW
Stimulus -> neural command -> excitation -> activation -> contraction -> force -> motion or stabilisation -> feedback.
Branches: cardiac pacemaking; autonomic smooth muscle regulation.

33. INFERENCE RULES
IF muscle crosses joint AND muscle develops tension THEN it MAY contribute to joint torque.
IF force acts with zero perpendicular moment arm THEN torque about that axis = 0.
IF contraction occurs THEN ATP turnover is required.
IF EMG rises THEN do NOT infer a fixed proportional rise in force without a calibrated model.

34. NON-INFERENCE RULES
Do not infer pathology from one measurement.
Do not equate muscle soreness with structural injury.
Do not infer muscle strength solely from muscle size.
Do not classify all involuntary contractions as pathological.

35. WORKED EXAMPLE: TORQUE
Given perpendicular moment arm r=0.04 m and tendon force F=500 N:
tau = 0.04 * 500 = 20 N m.
Assumptions: force line of action and axis specified; other forces ignored.

36. WORKED EXAMPLE: POWER
Given joint torque tau=30 N m and angular velocity omega=2 rad/s:
P = tau*omega = 60 W under aligned sign convention.

37. WORKED EXAMPLE: STRESS
Given force 100 N over area 2.0e-4 m^2:
sigma = 100/(2.0e-4) = 5.0e5 Pa = 0.5 MPa.
This is an average nominal stress, not local microscopic stress.

38. RELATIONSHIP GRAPH
MuscularSystem --contains--> SkeletalMuscle.
SkeletalMuscle --contains--> Fascicle.
Fascicle --contains--> MuscleFibre.
MuscleFibre --contains--> Sarcomere.
Sarcomere --contains--> ActinFilament.
Sarcomere --contains--> MyosinFilament.
MotorNeuron --innervates--> MuscleFibre.
Tendon --connects--> MuscleAndBone.
MuscleContraction --generates--> Force.
Force --mayGenerate--> JointTorque.

39. SEMANTIC EQUIVALENCE
'Skeletal muscle fibre' ~= 'skeletal myofibre' in matching contexts.
'Muscle' != 'muscle fibre' (organ vs cell).
'Muscle activation' != 'muscle force'.
'Contraction' != 'shortening' (isometric contractions exist).

40. VALIDATION RULES
Check taxonomic types, units, sign conventions and anatomical references.
Reject unqualified universal statements about fibre type, innervation or control.
Check that cited measurements distinguish observed data from model estimates.

41. EVIDENCE AND CONFIDENCE
CONFIDENCE := {level: low|medium|high, basis: source|measurement|model|inference, limitations: text}.
Well-established anatomy may receive high confidence; patient-specific inference needs direct evidence.
Do not invent numerical confidence probabilities.

42. PROVENANCE
Store source URI, author, timestamp, method, measurement units, sample and uncertainty.
Maintain distinctions between educational model, experimental result and clinical interpretation.

43. UPDATE_MODEL
Trigger update on revised anatomical nomenclature, accepted physiological evidence or model correction.
Version changes should retain previous identifiers and a change log.

44. FLOW_HASH
FLOW_HASH := SHA256(canonical_UTF8_content_excluding_hash_field).
Hash must be calculated by the publishing pipeline; no fabricated hash value.

45. AI_CONSUMPTION
Expose machine-readable types, predicates, formulas, constraints, provenance and confidence.
Preserve explicit negative inference rules and modelling assumptions.
Suitable for retrieval, educational reasoning and ontology alignment, not autonomous diagnosis.

46. CROSS-ONTOLOGY LINKS
Human Body Ontology; Skeletal System Ontology; Nervous System Ontology; Tissue Ontology; Cell Ontology; Mechanical System Ontologies; Biological Ontologies.

47. COMPLETENESS CHECK
Required sections: 01-47 sequential.
Required fields: FLOW ALGEBRA, SOURCE, AUTHORS, CONFIDENCE, SEMANTIC EQUIVALENCE, FLOW_HASH, UPDATE_MODEL, AI_CONSUMPTION.
Status: scientific synthesis, not verified against source page.

END FLOW ALGEBRA — MUSCULAR SYSTEM ONTOLOGY