Odeh M, Schnall R, Gavriely N, Oliven A
Department of Medicine B, Bnai-Zion Medical Center, Haifa, Israel.
Respir Physiol. 1993 May;92(2):139-50. doi: 10.1016/0034-5687(93)90034-8.
The activation of upper airway (UAW) muscles is believed to increase UAW patency to air flow. To evaluate the mechanisms by which UAW muscles act to prevent UAW collapse, pressure-flow relationships of the isolated UAW as well as the negative pressure required to cause UAW collapse (Pcrit) were assessed before and during electrical stimulation of four UAW muscle pairs in anesthetized dogs. Stimulation of each of the muscles shifted the pressure-flow curve toward lower pressures for any given flow rate, indicating UAW dilatation. UAW resistance decreased from 7.9 +/- 0.6 to 0.4 +/- 0.1, 2.7 +/- 0.6, 2.3 +/- 0.8 and to 4.8 +/- 1.5 cmH2O.L-1.sec during genioglossus, geniohyoid, sternothyroid and sternohyoid stimulation respectively (P < 0.01 in all cases). However, only genioglossus stimulation significantly increased Pcrit (from -3.4 +/- 0.6 to -12.0 +/- 1.8 cmH2O, P < 0.001). Relaxation of the genioglossus thus appears to produce the main impediment to air flow through the UAW, and contraction of this muscle improves UAW patency both by dilating the supraglottic airway and by stiffening its walls.
上气道（UAW）肌肉的激活被认为可增加上气道对气流的通畅性。为了评估上气道肌肉防止上气道塌陷的作用机制，在麻醉犬中，于电刺激四对上气道肌肉之前和期间，评估了离体上气道的压力-流量关系以及导致上气道塌陷所需的负压（Pcrit）。对于任何给定的流速，刺激每块肌肉都会使压力-流量曲线向较低压力方向移动，表明上气道扩张。在颏舌肌、颏舌骨肌、胸骨甲状肌和胸骨舌骨肌刺激期间，上气道阻力分别从7.9±0.6降至0.4±0.1、2.7±0.6、2.3±0.8和4.8±1.5 cmH₂O·L⁻¹·s⁻¹（所有情况P<0.01）。然而，只有颏舌肌刺激显著增加了Pcrit（从-3.4±0.6升至-12.0±1.8 cmH₂O，P<0.001）。因此，颏舌肌的松弛似乎是气流通过上气道的主要阻碍，而该肌肉的收缩通过扩张声门上气道和加固其壁来改善上气道通畅性。
