GLOSSARY

PI3K–Akt Insulin Signaling
Insulin-linked PI3K–Akt signaling regulates GLUT4 trafficking, glycogen-related pathways and other metabolic processes.

Coordinated glucose regulation

Islet output integrates nutrients, autonomic inputs, incretin signals and local cell-to-cell communication. Insulin and glucagon act on different tissues through distinct receptor pathways. Secretion, circulating concentration, insulin sensitivity and glucose disposal are related but separate quantities.

Interpreting the mechanism

Phosphorylation of one component does not independently quantify whole-body insulin sensitivity.

During movement and recovery

Contracting muscle can increase glucose uptake while circulating insulin declines. Hepatic glucose output and carbohydrate availability help match demand. People using glucose-lowering medicines may have different exercise responses, so general physiology does not replace individualized clinical planning.