PARVIZ M. POUR / SCIENCE PHOTO LIBRARY PARVIZ M. POUR / SCIENCE PHOTO LIBRARY
Islet of Langerhans. Light micrograph of a cross section through an islet of Langerhans in the human pancreas. The islet (brown) is composed of clumps of secretory cells. The main secretions from these cells are the hormones glucagon and insulin that control blood sugar. These cells are endocrine, their secretions go straight into the bloodstream. The cells surrounding the islet are packed into secretory acini (green) which secrete digestive enzymes. This part of the pancreas is exocrine, as the enzymes pass straight out into the gut via ducts. Magnification unknown.
Model release not required. Property release not required.