Midttun M, Sejrsen P
Department of Medical Physiology, The Panum Institute, University of Copenhagen, Denmark.
Clin Physiol. 1996 May;16(3):275-89. doi: 10.1111/j.1475-097x.1996.tb00574.x.
Measurements of blood flow rate in the pulp of the thumb, the first toe, the ear lobe, and the nose were performed using the heat-washout method, and the 133Xe-washout method under orthostatic changes in humans. Blood flow rate measured by the heat-washout method in the thumb was about 127.5 ml (100 g x min)-1 at heart level in two subjects, (n=10), and in the pulp of the first toe in 6 subjects (n=12) 49.3 ml (100 g x min)-1 at heart level. Above heart level blood flow rate decreased with the falling pressure head, and 50 cm below heart level blood flow remained unchanged compared to heart level. The arterioles supplying the capillaries in this region showed autoregulation of blood flow to 50 cm above heart level, but a veno-arteriolar reflex was not present. Blood flow rate in the ear lobe and on the side of the nose showed a similar pattern of reaction, with a blood flow rate in the arteriovenous anastomoses of about 100 ml (100 g x min)-1 in sitting position.
在人体直立位变化时，采用热洗脱法和¹³³氙洗脱法对拇指、拇趾、耳垂和鼻尖处的血流量进行了测量。两名受试者（n = 10）采用热洗脱法测得拇指在心脏水平处的血流量约为127.5 ml/（100 g·min）⁻¹，六名受试者（n = 12）拇趾在心脏水平处的血流量为49.3 ml/（100 g·min）⁻¹。高于心脏水平时，血流量随压力头下降而降低，低于心脏水平50 cm处的血流量与心脏水平相比保持不变。该区域供应毛细血管的小动脉在高于心脏水平50 cm处表现出血流自动调节，但不存在静脉 - 小动脉反射。耳垂和鼻尖处的血流量表现出类似的反应模式，坐位时动静脉吻合处的血流量约为100 ml/（100 g·min）⁻¹。
