Systems Physiology

Systems physiology examines how organ systems cooperate through dynamic networks of interaction to sustain homeostasis and generate complex organismal behaviours. Rather than studying isolated cells or pathways, it integrates multiple scales—from molecular signals and cellular networks to tissue microcirculation and whole-body reflexes—and investigates how feedback, delay and coupling across the cardiovascular, respiratory, neural, renal, immune and other systems underlie health and disease. For example, coordinated adjustments in vascular tone, lymphatic drainage and cardiac output buffer volume shifts in heart failure; interactions between carotid chemoreceptors, respiratory centres and pulmonary dynamics regulate ventilation under hypoxia; and neurovascular and astrocyte-mediated coupling matches local blood flow to neuronal demand. Advances draw on in vivo multimodal monitoring, single-cell transcriptomics of inter-organ ligand–receptor axes, high-resolution imaging of perfusion heterogeneity, and mathematical frameworks—such as delay-stability analysis and network graphs—to characterise emergent properties. By revealing how perturbations propagate through organ networks, this discipline informs novel biomarkers (for instance perfusion covariance patterns) and multifaceted interventions—from β-blockade plus anabolic hormones in fracture repair to device-based modulation of lymph flow—aimed at restoring system-level balance.

Research from Nature Portfolio

Work in model systems has pinpointed mitochondrial NADH dehydrogenase activity as the essential determinant of acute oxygen chemoreception in glomus cells. Expression of a single-molecule yeast NADH oxidoreductase in complex I-deficient mice fully restores hypoxic ventilatory responses without recuperating proton pumping, demonstrating that electron transport alone underlies arterial chemoreception and suggesting gene-therapy routes for respiratory disorders. Complementing this, studies employing controlled hypercapnia have shown that neurovascular coupling—the rapid haemodynamic increase triggered by synaptic activity—remains intact despite exogenous CO₂-mediated acidification, confirming that feedforward neuronal signals, rather than metabolic by-products, dominate local vasodilation and refining strategies to protect cerebral perfusion in hypercapnic or hypoxic settings.

Systems Physiology publication trend

The graph below shows the total number of articles in systems physiology across all publications each year (not limited to Nature Index journals).

Technical terms

Neurovascular coupling: The mechanism by which neuronal activity signals to adjacent microvessels, producing rapid, local increases in cerebral blood flow.

Arterial chemoreception: The process by which specialised glomus cells detect changes in blood oxygen, CO₂ or pH and trigger ventilatory reflexes.

Feedforward signalling: Anticipatory transmission of activity-dependent signals from neurons to blood-vessel walls, initiating vasodilation independently of downstream metabolic by-products.

Hypoxia-inducible factor 2α (HIF-2α): A transcription factor that activates gene programmes conferring oxygen sensitivity and adaptive proliferation in peripheral chemoreceptor and paraganglionic cells.

Lymphatic drainage: The transport of interstitial fluid and macromolecules through lymphatic vessels back into the central venous circulation, crucial for interstitial fluid homeostasis.

Remote ischaemic preconditioning (RIPC): A protective technique involving brief, non-lethal limb ischaemia to induce systemic resilience against subsequent hypoxic or ischaemic insults.

Electron transport chain (complex I): A multienzyme assembly in mitochondrial inner membranes that oxidises NADH, transferring electrons to ubiquinone and underpinning oxygen-sensing and ATP synthesis.

References

1. Transgenic NADH dehydrogenase restores oxygen regulation of breathing in mitochondrial complex I-deficient mice. Nature Communications (2023).
2. Neurovascular coupling during hypercapnia in cerebral blood flow regulation. Nature Communications (2024).
3. Hif-2α programmes oxygen chemosensitivity in chromaffin cells. Journal of Clinical Investigation (2024).
4. Effects of acetazolamide combined with remote ischemic preconditioning on risk of acute mountain sickness: a randomized clinical trial. BMC Medicine (2024).
5. The interstitial compartment as a therapeutic target in heart failure. Frontiers in Cardiovascular Medicine (2022).
6. β-Receptor blocker enhances the anabolic effect of PTH after osteoporotic fracture. Bone Research (2024).