Air embolism and veins is greater than atmospheric pressure, an air embolus does not often happen when a blood vessel is injured. In the veins above the heart, such as in the head and neck, the venous pressure may be less than atmospheric and an injury may let air in. This is one reason why surgeons must be particularly careful when operating on the brain, and why the head of the bed is tilted down when inserting or removing a central venous catheter from the jugular or subclavian veins. When air enters the veins, it travels to the right side of the
Off-the-Neck Historic District Off-the-Neck Historic District The Off-the-Neck Historic District encompasses a well-preserved set of early 19th-century rural properties on Maine State Route 166 (SR 166) in Castine, Maine, as well as canal dug in 1779 by British forces during the American Revolutionary War across the neck separating the Bagaduce Peninsula (where the main village of Castine is located) from the mainland. The district takes its name from the fact that the included properties are just north of this neck on the mainland. The district was listed on the National Register of Historic Places in 1986. Maine State Route 166 (SR 166) is