Venous flow and valves

More fun with the new Zonareā€¦

With high resolution imaging you can see venous flow without using Doppler.

Here is a clip of the posterior tibial vein in the calf. Note the 2 valves and also the respiratory phasicity of flow.

Here is a clip of a valve in the IJ (the flow pattern is more chaotic, as there is backwash from heart contractions)

In the legs, venous flow slows during inspiration (due to increased intra-abdominal pressure). The opposite pattern occurs in the arms and neck, as inspiration sucks blood toward the heart.

– steve