Chest muscles
Aus Dornheim Anatomy
The Mm. intercostales and M. transversus thoracis muscles belong to the autochthonous chest musculature, which is an important part of the respiratory musculature. The Mm. scaleni belong to the deep neck muscles. As they functionally act as respiratory support muscles, they are also explained at this point.
Neighboring structures
autochthonous chest muscles - Mm. intercostales und M. transversus thoracis
| Mm. intercostales externi | Mm. intercostales interni | M. transversus thoracis | |
| origin | Lower margin of a rib (Tuberculum costae up to Cartilage-bone junction) | upper margin of a rib (Angulus costae to Sternum) | inside rib cartilage of 2nd-6th rib |
| insertion | upper margin of next deeper rib progression: from posterior top to posterior bottom (Tuberculum costae to cartilage-bone junction) |
lower edge of next highest rib progression: from back bottom to front top (Angulus costae to sternum) |
Inside of Corpus sterni and Processus xiphoideus sterni |
| function | rib lifter (inspiration), tighten the interrib spaces; stabilization of the thoracic wall |
rib countersink (expiration); tighten the interrib spaces; stabilization of the thoracic wall |
Rib countersink (expiration) |
| innervation | Nervi intercostales 1-11 | Nervi intercostales 1-11 | Nervi intercostales 2-6 |
Mm. scaleni
| M. scalenus anterior | M. scalenus medius | M. scalenus posterior | |
| origin | Tubercula anteriora of the transverse processes of the 3rd-6th cervical vertebra | Tubercula posteriora of the transverse processes of the 3rd - 7th cervical vertebra | Tubercula posteriora of the transverse processes of the 5th-7th cervical vertebra |
| insertion | Tuberculum musculi scaleni anterioris of the 1st rib | 1st rib (dorsal of Sulcus arteriae subclaviae) | Outside surface of the 2nd rib |
| function |
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| innervation | direct branches from the spinal nerves cervical plexus and brachial plexus (C3-6) | ||
Free Exploration
Look at the structure of the chest muscles in 3D and explore it freely. Afterwards you can test your acquired knowledge by the exercises.
