80 



Bones of the Thorax. 



Capitulum costae 



Costa I Costa II 



Tuberositas costae II 



99 and 10O. First and second ribs of right side, 



COStae I et II, from above and without. 



The first two ribs present certain peculiarities. 



The costa I (see also Figs. 105 and 107) is on the whole directed equally 

 obliquely forward and downward and possesses an upper surface directed somewhat 

 lateralward and a lower directed somewhat medianward. On the upper surface a little 

 in front of the middle, near the medial border is a small nodule (sometimes only a 

 roughening) , tuber culum scaleni [Lisfranci] (for the attachment of the m. scalenus 

 anterior); a very shallow furrow in front of this serves for the v. subclavia, a curve 

 behind this, the sulcus subclaviae, for the a. subclavia is usually somewhat more distinctly 

 marked. Behind the latter lies another roughened area for the m. scalenus medius. 



The costa II (see also Figs. 105 and 107) resembles the other ribs in its form 

 much more than it does the first rib. On its lateral surface, somewhat in front of the 

 middle, is a roughened area, the tuber ositas costae II (for the attachment of prongs 

 of the m. serratus anterior). 



