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
Ultrasonography of chronic venous insufficiency of the legs and hemodynamics of the lower limb veins. Particular veins of the DVS and the SVS are looked at. The great saphenous vein (GSV), and the small saphenous vein (SSV) are superficial veins which drain into respectively, the common femoral vein and the popliteal vein. These veins are deep veins. Perforator veins drain superficial veins into the deep veins. Three anatomic compartments are described (as networks), (N1) containing the deep veins, (N2) containing the perforator veins, and (N3) containing the superficial veins, known as the saphenous compartment. This compartmentalisation makes it easier for the examiner to systematize and map. The GSV