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).
These blockages often cause insufficient blood flow to a patientâs heart muscle. Collateral vessels benefit some myocardial ischemia patients when their extra vessels open up and supply blood to the heart, partially replacing the lack of circulation in the blocked arteries.he collateral vessels can be microscopic or they may grow larger. In some individuals, enlarged collateral blood vessels begin to transport blood. Some cases of active collateral circulation are beneficial, while in other instances, this kind of added blood circulation can cause serious medical complications.