GLOSSARY

Glucagon Receptor
The glucagon receptor is a G protein-coupled receptor with an important hepatic role. Activation commonly engages Gs, adenylyl cyclase, cAMP and downstream phosphorylation mechanisms.

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

The final glucose response depends on available substrates, glycogen stores and interacting hormones. A receptor signal and the measured rate of hepatic glucose production are different levels of observation.

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.