Internal Jugular and Vertebral Vein Postural Flow Dependency 1-G

• Collapse of internal jugular veins, external tissue pressure, when upright

• Internal jugular veins- main outflow supine

• Vertebral veins- main outflow standing

• Gisolf, et al, standing 1-G CVP= -8.2mmHg,

• internal jugular vein pressure= -2.7mmHg.

• Pressure differential due to external tissue pressure causing higher pressure in internal jugular veins when gravitationally/hydrostatically it should be lower pressure (-21mmHg which is lost in microgravity)

Notes:

Some studies have indicated that the cause is collapse of the internal jugular veins by external tissue pressure when standing, but the exact tissues causing this have not been described.

Gisolf, standing CVP vs standing internal jugular venous pressure. The pressure increase in the internal jugular veins is due to the tissue pressure.

Now we need to figure out what tissues are causing the pressure. In doing so I performed numerous ultrasound studies, many on myself, which made it clear where the obstruction was and what tissues were causing it.