THE BONES. 75 



times present at the superior border of the sternum, one upon 

 either side ; they are generally rather larger than the Pisiform 

 bone. 



85. II. Costse, Ribs, twenty-four. 



Position : between the vertebral column and sternum ; twelve 

 upon either side. 



Figure : flat, narrow, long, thin, elliptically curved, and directed 

 from behind forwards, from above downwards. 



Breadth : From three to six lines ; thickness : one line. 



Division: Costse verse, 7; Costse spurise, false ribs, 5 upon 

 either side. 



Portions of each rib: Body, posterior and anterior termination. 



Connection : with the twelve dorsal vertebrae, with the cartilages 

 of the ribs and the sternum, with the last bone by means of the 

 cartilages of the seven superior, or true ribs. 



1. Posterior extremity, Head, presents : Capitulum with two semi-articular 

 surfaces, uniting with bodies of the dorsal vertebrae, from the second to the 

 tenth rib between the two vertebrae, on the eleventh and twelfth rib in the 

 centre of the body [on the eleventh above the centre]. Neck, the thinnest 

 part ; rough, in relation with the transverse proc. of the vertebra above, it ; 

 Tuberculum, tubercle, the internal portion, for the transverse process of the 

 vertebra below ; the external for ligaments ; the termination of the neck of 

 the rib. 



2. Body, central portion, with the Angulus co&tse not far from the Tubercle , 

 has an external convex, rough, and an internal, concave, smooth surface, a 

 thick superior, a sharp inferior border. On the last, within : Sulcus coslalis, 

 for the art., ven., and nerv. intercostalis. 



3. Anterior extremity, with oval articular surfaces [fossae] for the cartilages ; 

 at the last an obtuse angle. 



The true ribs unite by their cartilages, immediately, with the 

 sternum at an acute angle ; increasing in length from above to 

 below. 



The false ribs, c. spurise, five, decrease from above to below in 

 length ; as well as their cartilages. 



Particular ribs. 1. First rib, the smallest and broadest, with short and 

 thick cartilage almost immoveable. The external surface ; for ven. subclavia, 

 before, for art. xubclavia, behind m. scalenus anterius and subclavius, looks 

 upwards, the superior border inwards. On the Capitulum one articular sur- 

 face ; Collum, long, cylindrical ; Tuberculum, projecting, angular ; anterior 

 extremity broad. 



2. Second rib, as long again as the first, may lie horizontal, the angle very 

 indistinct. External surface, above, for m. serratus post, sup., scalenus med. et 

 post. Internal surface obliquely downwards, with a very superficial groove. 



3. Third rib, much larger, more arched below and before: angle more 

 marked. 



