BLOOD FLOWS RADIALLY FROM CENTER OF ISLET TO THE PERIPHERY FACILITATING PARACRINE INHIBITION OF GLUCAGON SECRETION BY INSULIN
VENOUS BLOOD
ISLETS OF LANGERHANS
MANTLE FORMED BY a CELLS
 SECRETING GLUCAGON (20-25%)
CORE FORMED BY BETA CELLS SECRETING INSULIN
 (60-70 % OF TOTAL)
1 MILLION ISLETS EACH
CONTAINING ~2500 CELLS
 ARTERIAL BLOOD
 VENOUS BLOOD
b CELL
b CELL
SECRETORY
GRANULES