But these blood vessels are different from all the other blood vessels in our body. They are lined by a strange structure called the blood-brain barrier. It closely controls what is, and is not, allowed to leave the blood supply and enter the brain.It's your own personal customs and border security.We used to think of the blood-brain barrier as some kind of biological flyscreen.hey are lined by a strange structure called the blood-brain barrier. It closely controls what is, and is not, allowed to leave the blood supply and enter the brain. It's your own personal customs and border security. We used to think of the blood-brain barrier as some kind of biological flyscreen.
Follow this guide to find the best time to see Smoky Mountain fall colors. September. Fall in the Smokies begins in September, with the emerging changes occurring above 4,000 feet. Red, orange and yellow colors can be seen on sourwood, dogwood, maple, sassafras and birch trees. Drives recommended for September viewing are Parsons Branch Road, Newfound Gap Road and Clingmans Dome Road.
We spend a lot of time outdoors. We especially enjoy the crisp air and vibrant colors of autumn. For our school science project, we decided to explore the many different leaf colors we notice in the fall and find out what makes these leaves change from green to brilliant orange, yellow and red.e especially enjoy the crisp air and vibrant colors of autumn. For our school science project, we decided to explore the many different leaf colors we notice in the fall and find out what makes these leaves change from green to brilliant orange, yellow and red.