GLOSSARY

First-Phase Insulin Secretion
First-phase insulin secretion is the rapid early response to a defined glucose stimulus, especially evident after intravenous glucose. It involves release from readily available secretory granule pools.

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.

A distinction that matters. Its magnitude depends on stimulus delivery and beta-cell health. An ordinary meal combines absorption, incretins and neural inputs, so the same phase cannot be inferred directly from a single post-meal sample.

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.