Fig. 1
From: Q&A: insulin secretion and type 2 diabetes: why do β-cells fail?
Glucose homeostasis. A rise in blood glucose triggers insulin secretion from β-cells (blue) within the pancreatic islets. Insulin lowers blood glucose by acting on target tissues, suppressing glucose output from the liver and stimulating glucose uptake into muscle and fat. α-cells (yellow) are the glucagon-secreting cells of the pancreas; δ-cells (green) secrete somatostatin