THE SKELETON. 



39 



A process is a projection or elevation. 



A tuberosity is a rough obtuse pro- 

 cess. 



A tubercle is a small and usually more 

 or less pointed process. 



A condyle is a rounded and somewhat 

 elongated smooth articular process. The 

 distal end of the femur presents a pair 

 of condyles (Fig. 40). 



A fossa is an irregular depressed area 



(Fig. 30). 



A foramen is an aperture for the pas- 

 sage of vessels or nerves. 



The shaft is the body or middle por- 

 tion of an elongated bone. 



The head is a spheroidal prominence 

 at one end of an elongated bone (Fig. 

 40). 



The epiphysis is a small process of 

 bone ossified from a separate center. In 

 the young animal it is attached to the 

 main bone by cartilage, but in the adult 

 becomes a part of the main bone (Fig. 

 12). The femur has four epiphyses, one 

 for the head, one for the distal extremity, 

 and one for each trochanter process (Fig. 

 40). With the exception of the pha- 

 langes, metacarpals, and metatarsals, all 

 of the long bones have an epiphysis at 

 each extremity. In the human, these 

 epiphyses do not unite with the shaft 

 before the sixteenth year. Diploe is 

 the spongy layer of bone between the 

 layers of the flat bones (Fig. 18). 



FIG. 13. LONGITU- 

 DINAL SECTION 

 OF THE FEMUR. 



w<l, Medullary cav- 

 ity; d and h, can- 

 cellous tissue ; tr. 

 cancellous tissue 

 of trochanter pro- 

 cess ; b, compact 

 bony tissue. 



compact surface 



