external intercostal muscles


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Related to external intercostal muscles: Internal intercostal muscles, Internal intercostals

external intercostal muscles

The outer layer of muscles between the ribs, originating on the lower margin of each rib and inserted on the upper margin of the next rib. During inspiration, they draw adjacent ribs together, pulling them upward and outward, and increasing the volume of the chest cavity. They are controlled by the intercostal nerves.
See also: muscle
References in periodicals archive ?
Thus, also stimulating external intercostal muscles or abdominal muscles is not necessary to maintain adequate alveolar ventilation in a nonexercising, paralyzed individual [4].
Contraction of the external intercostal muscles pulls the ribs outward, thereby preventing the inward movement of the upper rib cage; the net effect is to augment the volume of inspired air (Figure 3).
The larger external intercostal muscles assist in inspiration when the tidal volume is large by pulling the ribs upward and outward.

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