Effective in 2003, the Bureaus of Alcohol, Tobacco and Firearms (ATF), Federal Law Enforcement Training Center (FLETC), U.S. Customs, and the United States Secret Service (USSS) are no longer Bureaus of the Department of the Treasury.
The endocrine system is made up of a network of glands. These glands secrete hormones to regulate many bodily functions, including growth and metabolism. Endocrine diseases are common and usually occur when glands produce an incorrect amount of hormones.
Pancreatic islets house three major cell types, each of which produces a different endocrine product: 1  Alpha cells (A cells) secrete the hormone glucagon. 2  Beta cells (B cells) produce insulin and are the most abundant of the islet cells.