98 ATLAS AND TEXT-BOOK OF HUMAN ANATOMY. 



Fig. 137. — The right femur seen from behind (f). 



Fig. 138. — The right femur seen from the inner surface (f). 



Fig. 139. — The right femur seen from in front (§•). 



Fig. 140. — The upper end of the right femur seen from behind (£). 



Fig. 141. — The lower end of the right femur seen from below (^). 



Fig. 142. — The patella seen from in front ({). 



Fig. 143. — The patella seen from behind (|). 



the upper and the lower extremity of the bone, passing toward the trochanters above and to the 

 epicondyles below. 



The outer lip of the linea aspera passes upward to a long broad elevation, the gluteal tuber- 

 osity* (Fig. 140), which is usually flat but markedly roughened, and receives the greater portion 

 of the insertion of the glutaeus maximus muscle. The internal lip becomes less distinct as it 

 passes upward and is continuous with the intertrochanteric line. Parallel to the upper part 

 of the inner lip and somewhat to the outer side of it is situated a second rough line, the pectineal 

 line (Fig. 140), for the insertion of the pectineus muscle. 



Toward the lower extremity of the femur the two lips of the linea aspera gradually diverge 

 and form the boundaries of an almost plane triangular area upon the posterior surface of the 

 bone, the popliteal surface (Fig. 137). Upon the line, above its middle, there are usually one or 

 more nutrient foramina which lead into canals pursuing a distinct upward (proximal) direction. 



The shaft of the femur exhibits a distinct curvature, which is convex anteriorly (Fig. 139), 

 and upon its anterior broad portion there may be distinguished an antero-internal, an antero- 

 external, and a posterior surface. The linea aspera furnishes either the origin or the insertion 

 for a large number of muscles. 



The inferior extremity of the femur is very broad, and presents two convex condyles 

 (Fig. 137), a larger internal condyle and a smaller external condyle, which are directed posteriorly 

 and are separated from each other by the intercondyloid fossa, an intercondyloid line separating 

 this fossa from the popliteal surface. Anteriorly (Fig. 141) the cartilaginous surfaces of both 

 condyles are continuous with an articular surface, the patellar surface, which is concave from 

 side to side and convex from above downward, so that the entire articular surface of the lower 

 end of the femur is shaped somewhat like a horseshoe. Above the condyles upon the lateral 

 surfaces of the lower end of the bone are situated two rough and slightly prominent processes, 

 the epicondyles (Figs. 137, 138, and 141), which are termed the internal epicondyle and the 

 external epicondyle. The lower portions of the lips of the linea aspera run downward to the 

 epicondyles, which give origin to the gastrocnemius muscle. 



Like most of the long bones, the femur is developed from a diaphyseal and two primary epiphyseal centers. The 

 diaphyseal center appears as early as the seventh week of embryonic life, and while the lower epiphyseal center 

 is usually visible at birth, the center for the head of the femur does not appear until after birth (at the end of 

 the first year). At a later period special epiphyseal centers appear in the greater trochanter (fourth year) and 

 in the lesser trochanter (thirteenth to fourteenth year). 



Although the center for the lesser trochanter appears later than any of the other epiphyseal centers, it is the 



* Sometimes the gluteal tuberosity develops into a more pronounced projection, the third trochanter. 



