Meninges- three layers of connective tissue
1) Dura Mater: tough top layer
2) Arachnoid Mater: middle; collagen/elastic fibers; spiderweb effect
3) Pia Mater: delicate and thin; bottom transparent layer made up of elastic/collagen fibers; blood vessels
If you are a smoker quit smoking. Eat three meals a day, doesn't mean you have to eat a lot. Eat alot of vegetables and fruits - at least 1/4 cup worth a day. Avoid processed/canned fruits as they most likely added sugar to it. Exercise daily at least half an hour a day. Stay hygienic. Eat more proteins than junk food. Lessen the amount of snacks a day to 1-2 each should be 100 cals or below. Avoid eating a lot of carbs as it can raise insulin and make you feel hungry often.
18 to somewhere around 20-21? Depends what culture tho