RQ-1A Predator is a long-endurance, medium-altitude unmanned aircraft system for surveillance and reconnaissance missions. Predator UAVs have been operational in Bosnia since 1995, where they have flown more than 600 missions for more than 4,000h in support of Nato, UN and US operations. Predator operated from a tactical control station located aboard the USS Carl Vinson, Nimitz class aircraft carrier.
Secretin functions as a type of fireman: it is released in response to acid in the small intestine, and stimulates the pancreas and bile ducts to release a flood of bicarbonate base, which neutralizes the acid. Secretin is also of some historical interest, as it was the first hormone to be discovered. similar, but quantitatively less important response to secretin is elicited by bile duct cells, resulting in additional bicarbonate being dumped into the small gut. As acid is neutralized by bicarbonate, the intestinal pH rises toward neutrality, and secretion of secretin is turned off.
Millions of cells form tissues and organs that all talk to each other via messages sent throughout the body. One type of messenger in the body are hormones. Hormones are chemical substances that travel through the blood and throughout the body to control bodily functions. One very important hormone is secretin. Secretin is a hormone that controls parts of the digestive system and maintains water balance in the body. It's released by the duodenum, the upper part of the small intestine. Let's explore the functions of secretin in closer detail.