part_of adult salivay gand type I acinus adult salivary gland type I acinus constrictor cell A pair of small cells that surround the acinar duct. The constrictor cells control the outflow of secretions from the acinus into the main salivary duct. Constrictor cells are found only in type I (agranular) acini. However, it is possible that theperitubular cells (neck cells) in the granular acini perform a similar role. Fig. 8-5, in Biology of Ticks ISBN:0-19-505910-7. TADS:0000539 TADS:0000539 default_namespace cell