192 PRACTICAL ANATOMY. 



Insertion Posterior part of second rib. 

 Nerve Brachial plexus. 



MUSCLES OF THE THORAX. 

 ELEVEN EXTERNAL INTERCOSTALS. 



Origin Inferior border of rib, above. 

 Insertion Superior border of rib, below. 

 Nerves Intercostals. 

 ELEVEN INTERNAL INTERCOSTALS. 



Origin Inferior border of rib, above. 

 Insertion Superior border of rib, below. 

 Nerves Intercostals. 



The external intercostals pass downward and forward, 

 and extend from tubercle of the ribs to costal cartilages. 

 The internal intercostals pass upward and inward, 

 and begin anteriorly at the sternum and extend back- 

 ward to the angle of ribs. 

 TWELVE LEVATORES COSTARUM. 



Origin Apices of transverse processes of dorsal ver- 

 tebrae. 



Insertion Pass downward and outward, and are in- 

 serted posterior to angles of ribs. 

 Nerve Intercostals. 

 INFRACOSTALES. 



Origin Fibres arise from inner surface of rib. 

 Insertion Into ribs below. 

 Ne rve Intercostal . 

 TRIANGULARIS STERNI. 



Origin Lower part of inner surface of sternum and 



costal cartilages. 

 Insertion Costal cartilages of third, fourth, and fifth 



ribs. 



Nerve Intercostal. 

 DIAPHRAGM. 



The diaphragm is a fibro-muscular partition be- 



