The body as enterprise architecture.

Normal function: Coordinates perception, movement, autonomic control, and cognition.

Failure modes: Lesions, seizures, degeneration, altered neurotransmission.

Step 1 relevance: Localize deficits and connect anatomy to function.

Normal function: Maintains forward flow under variable demand.

Failure modes: Pump failure, ischemia, valvular dysfunction, arrhythmias.

Step 1 relevance: Pressure-volume logic, murmurs, shock, pharmacology.

Normal function: Routes pressure, volume, and nutrients to tissues.

Failure modes: Atherosclerosis, vasculitis, thrombosis, aneurysm.

Step 1 relevance: Hemodynamics, endothelial injury, clotting, perfusion.

Normal function: Balances volume, electrolytes, acid-base status, and toxins.

Failure modes: Glomerular, tubular, obstructive, and vascular disease.

Step 1 relevance: Urinalysis, compensation, diuretics, nephron localization.

Normal function: Metabolizes, detoxifies, synthesizes, stores, and secretes bile.

Failure modes: Hepatitis, cirrhosis, cholestasis, metabolic overload.

Step 1 relevance: LFT patterns, portal hypertension, bilirubin, coagulation.

Normal function: Distinguishes self from threat and coordinates defense.

Failure modes: Autoimmunity, immunodeficiency, hypersensitivity, malignancy.

Step 1 relevance: Cytokines, cell types, infection risk, immune therapies.

Normal function: Uses hormones to coordinate distributed organ behavior.

Failure modes: Overproduction, underproduction, resistance, feedback disruption.

Step 1 relevance: Axis logic, feedback loops, diabetes, thyroid, adrenal.

Normal function: Exchanges oxygen and carbon dioxide while regulating pH.

Failure modes: Obstruction, restriction, diffusion defects, V/Q mismatch.

Step 1 relevance: PFTs, ABGs, hypoxemia, pulmonary pharmacology.