Both islet and insulin come from Latin insula (island) — because the pancreatic cells that make insulin looked like tiny islands under a microscope.
A very small island; in anatomy, a small cluster of cells distinct from the surrounding tissue, especially the islets of Langerhans in the pancreas.
From Old French islette, diminutive of isle (island), from Latin insula (island). The anatomical sense refers to isolated clusters of cells that resemble tiny islands within a larger tissue. Key roots: insula (Latin: "island").
The islets of Langerhans — tiny cell clusters in the pancreas that produce insulin — were named by Paul Langerhans in 1869, who noticed them as "islands" scattered through pancreatic tissue. The word insulin itself comes from the same Latin root insula (island), because the hormone was produced by these little islands. So both islet and insulin trace to the same