Pectoral Muscles 胸肌 The pectoral muscles consist of the pectoralis major and the pectoralis minor, which are fan-shaped muscles of the shoulder. They shape the anatomy of the breast.胸肌由胸大肌和胸小肌组成，它们是肩部的扇形肌肉，影响乳房的解剖结构。 The pectoralis minor lies under the pectoralis major and both form the anterior wall of the axilla where they can be palpated. The innervation is carried by the medial and the lateral pectoral nerves (direct branches of the brachial plexus).胸小肌位于胸大肌下，它们共同形成腋窝的前壁，我们可以触诊到。胸肌由胸内侧神经和胸外侧神经（臂丛神经直接发出的分支）支配。 The pectorals are located close in relation to the brachial plexus, and both the subclavian artery and vein, which all run between the muscle and the rib cage.胸肌与臂丛、锁骨下动脉和静脉的位置接近，它们都在肌肉和胸廓间走行。 The pectoralis major muscle is the most important muscle for the adduction and anteversion of the shoulder joint, which is why it is also known as the breaststroke muscle.胸大肌是肩关节内收和前倾最重要的肌肉，因此也被称为蛙泳肌。 It rotates the upper arm outwards and makes a powerful stroke movement called retroversion when the arms are elevated or, for example, in wood chopping. If the arms are fixed, the muscle lifts the trunk, which can be helpful in climbing or during inspiration.它向外旋转上臂，参与发出手臂抬高或劈柴等的后倾强冲击性活动。如果手臂固定不动，肌肉将提拉躯干，这有助于攀爬或吸气。 The pectoralis minor has two main functions.胸小肌有两大功能。 On one hand, it pulls the scapula anteriorly and inferiorly toward the ribs, known as abduction and depression respectively. 一方面，它可以拉肩胛骨向前，向下朝向肋骨，这两种运动分别称为外展和下压。 This leads to a dorsomedial movement of the inferior angle of the scapula. This movement is both helpful when retracting the elevated arm as well as moving the arm posteriorly behind the back.这会导致肩胛骨下角向背内侧运动。这种运动有助于收回抬高的手臂，以及向后移动手臂。 On the other hand, the pectoralis minor elevates the third to fifth ribs, given a fixed scapula, and expands the ribcage. By those means, it can also serve as an accessory muscle during inspiration.另一方面，肩胛骨固定不动时，胸小肌会抬高到第 3-5 肋，扩大胸腔。通过这些方式，它也在吸气期间充当辅助肌。 相关单词学习
Pectoralis
①发音和释义 pec•to•ral•is/ˈpektərəlɪs/ 胸肌Either of two large muscles of the chest. 单词 pectoralis的复数形式 pectorales（图源：太帅图库）
