National Letter of Intent. The National Letter of Intent (NLI) is a document used to indicate a student athlete's commitment to participating National Collegiate Athletic Association (NCAA) colleges and universities in the United States.
Collateral Vessel Closure. Collateral vessels are abnormal blood vessels that connect the aorta with the pulmonary arteries. The aorta is a blood vessel that carries blood from the heart to arteries throughout the body.Pulmonary arteries are the vessels that transfer blood from the heart back to the lungs for oxygen.Everyone has collateral vessels, but they're normally small and not in use.They become enlarged in some people with congenital heart disease (heart disease that's present since birth).ulmonary arteries are the vessels that transfer blood from the heart back to the lungs for oxygen. Everyone has collateral vessels, but they're normally small and not in use. They become enlarged in some people with congenital heart disease (heart disease that's present since birth).
Medical Definition of Collateral. Collateral: In anatomy, a collateral is a subordinate or accessory part. A collateral is also a side branch, as of a blood vessel or nerve. After a coronary artery occlusion, collaterals (that is, collateral vessels) often develop to shunt blood around the blockage. The word collateral comes from the Latin col-, with + latus, side = with the side, situated at the side.