TABLE 1.
Comparison of the effects of spaceflight and head-down bedrest (HDBR) on blood volume (+: increased, −: decreased). Adapted and modified from Diedrich et al. (2007).
Spaceflight | HDBR | |
---|---|---|
Headward fluid shift | + | + |
Hunger | − | +/- |
Thirst | − | +/- |
Diuresis | +/-, (explained above) | + |
Renal response to fluid & salt | Reset | Preserved |
Salt retention | + | Unknown |
Atrial natriuretic peptide | Reset to lower levels | + |
Mechanical compression of thorax | − | Maintained |
Central venous pressure | − | Transiently increased |
Radiation | + | NA |