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 .
Some countries require that your passport be valid at least six months beyond the dates of your trip. Some airlines will not allow you to board if this requirement is not met. Consider the following scenario: A country requires that you have at least six months of validity on your passport. You currently have seven months of validity on your passport. However, your trip is two months from now. At that point, you will only have five months of validity remaining on your passport which is not enough to satisfy that country's entry requirements. In this situation, you would need to renew your passport before you can make your trip. Check our Country Specific Information to learn about entry and exit requirements for the country or countries in which you are traveling. Watch this short YouTube video about why you need at least six months of validity on your U.S. passport! If your passport has already expired, you may still be able to renew your passport by mail. See How to Renew Your U.S. Passport.