Letâs start with military unmanned aircraft. According to the annual almanac published by the Air Force Association (http://www.airforcemag.com/Magaz...), as of mid-2016: MQ-1 Predators: 268 produced, 139 in service, 111 destroyed in accidents; MQ-9 Reapers: 346 (including those as yet undelivered), 165 in service, 24 destroyed in accidents
Secretion is the process of elaborating, releasing, and oozing chemicals, or a secreted chemical substance from a cell or gland.In contrast to excretion, the substance may have a certain function, rather than being a waste product.ecretion is the process of elaborating, releasing, and oozing chemicals, or a secreted chemical substance from a cell or gland.
Salivary Glands and Saliva. Saliva is produced in and secreted from salivary glands. The basic secretory units of salivary glands are clusters of cells called an acini. These cells secrete a fluid that contains water, electrolytes, mucus and enzymes, all of which flow out of the acinus into collecting ducts.ost animals have three major pairs of salivary glands that differ in the type of secretion they produce: 1  parotid glands produce a serous, watery secretion. 2  submaxillary (mandibular) glands produce a mixed serous and mucous secretion.