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).
This is often a result of anastamoses, branches formed between adjacent blood vessels. Collateral circulation can be established in the venous system (between veins) or in the arterial system (between arteries). It may arise from pathological conditions such as congestion or ischaemia.