Hormones | Back to Top. The endocrine system is a collection of glands that secrete chemical messages we call hormones. These signals are passed through the blood to arrive at a target organ, which has cells possessing the appropriate receptor. Exocrine glands (not part of the endocrine system) secrete products that are passed outside the body. Sweat glands, salivary glands, and digestive glands are examples of exocrine glands. The roles of hormones in selecting target cells and delivering the hormonal message.
Passport validity and the least six month rule. The requirement that a passport is valid for travel for six months beyond the holderâs stay in the United States is waived for certain nationalities, including British Citizens. Please visit 9 FAM 403.9 for more information .
We recommend applying for a passport as soon as you enroll on a tour, as it can take up to eight weeks to process. U.S. citizens traveling abroad must bring a passport that is valid for at least six months after the tourâs return and has at least three blank pages. Airlines will not permit you to travel if the name on your ticket does not match your passport exactly.