在微血管分叉的支管中,红细胞压积常低于主管上游的值,造成这一现象的原因之一是“血浆撇取”效应,即由于主管中近壁面处有一无细胞的血浆层,从而使流入支管中的红细胞较少。要计算这一效应的大小,关键是确定主管上游横截面分界 One of the causes of this phenomenon in hematocrit branches is often lower than the value of the upstream of the main tube, which is due to the “plasma skimming” effect, ie, due to the presence of a cell-free plasma layer at the mid-near wall of the competent Reduce inflow of red blood cells into the branch. To calculate the magnitude of this effect, the key is to determine the boundaries of the competent upstream cross-sections