TRIANGULARIS STERNI - A PRIMARY MUSCLE OF BREATHING IN THE DOG
TRIANGULARIS STERNI - A PRIMARY MUSCLE OF BREATHING IN THE DOG
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DOI：
10.1152/jappl.1986.60.1.14
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发表时间：
1986-01-01
影响因子：
3.3
通讯作者：
NINANE, V
中科院分区：
文献类型：
--
作者：
DETROYER, A;NINANE, V
在仰卧位麻醉犬上研究了胸三角肌（胸横肌）的单独动作、神经激活模式和对正常呼吸的机械贡献。用线性位移传感器测量肋骨和胸骨的轴向位移。强直刺激呼吸暂停动物的胸骨三角肌导致肋骨明显向尾侧移位，胸骨中度向颅侧移位，肺容量减少。在安静的呼吸，总是有一个有节奏的激活肌肉的阶段与呼气是独立的存在或不存在的活动在腹部和内部骨间肋间肌。这种阶段性的呼气活动在胸骨三角肌是大幅度的，并导致肋骨更尾部和胸骨更颅在自发呼气暂停比在放松。对清醒动物的其他研究表明，胸骨三角肌的节律性激活发生在所有体位，而不是由麻醉引起的。这些发现表明，在狗的呼气不是一个被动的过程，呼气末的胸腔容积不是由静态力的平衡单独决定。相反，在整个呼气过程中，通过胸骨三角肌的收缩，它被主动地确定并保持在其松弛体积以下。使用这块肌肉可能会通过增加胸骨旁肋间肌的长度并承担其部分工作来促进吸气。
The isolated action, pattern of neural activation, and mechanical contribution to eupnea of the triangularis sterni (transversus thoracis) muscle were studied in supine anesthetized dogs. Linear displacement transducers were used to measure the axial displacements of the ribs and sternum. Tetanic stimulation of the triangularis sterni in the apneic animal caused a marked caudal displacement of the ribs, a moderate cranial displacement of the sternum, and a decrease in lung volume. During quiet breathing, there was invariably a rhythmic activation of the muscle in phase with expiration that was independent of the presence or absence of activity in the abdominal and internal interosseous intercostal muscles. This phasic expiratory activity in the triangularis sterni was of large amplitude and caused the ribs to be more caudal and the sternum to be more cranial during the spontaneous expiratory pause than during relaxation. Additional studies on awake animals showed that rhythmic activation of the triangularis sterni occurs in all body positions and is not caused by anesthesia. These findings indicate that expiration in the dog is not a passive process and that the end-expiratory volume of the rib cage is not determined by an equilibrium of static forces alone. Rather, it is actively determined and maintained below its relaxation volume by contraction of the triangularis sterni throughout expiration. The use of this muscle is likely to facilitate inspiration by increasing the length of the parasternal intercostals and taking on a portion of their work.