152 



THE SKELETON 



Ligaments : — 



Capsuhir of hip-joint. External lateral of knee-joint. 



Litianicntiuu teres. Anterior crucial. 



Internal lateral of knee-joint. Posterior crucial. 



Posterior, or Winslow's. 



Blood-supply. — The head and neck of the femur receive branches from the 

 sciatic, i)l)turator, and circumflex arteries. The trochanter receives twigs from the 

 circumflex arteries. The nutrient vessel for the shaft is derived from the second 

 perforating; it enters near the middle of the linea aspera, and is directed towards 

 the head of tlie bone. The condyles are nourished by articular branches from the 

 jtoplitcal and the anastomotic of the femoral. 



Ossification. — The shaft of the femur begins to ossify in the seventh week of 

 intra-uterine life. Early in the ninth month a nucleus appears for the condyles. 

 During the iirst year the nucleus for the head of the bone is visible, and one for 

 the greater troclianter in the fourth year. The centre for the lesser trochanter is 

 visible about the thirteenth or fourteenth year. The lesser trochanter joins the 

 shaft at the eighteenth, the greater trochanter at the nineteenth, the head about the 

 twentieth, and the condjdes at the twenty-first year. 



The neck of the femur is an apophysis, or outgrowth from the shaft. The line 

 of fusion of the condyloid epiphysis passes through the adductor tubercle. 



The morpliological relation of the patellar facet to the articular portions of the 

 condyles is worth notice. In a few mammals, such as the ox, this facet remains 

 separated from the condyles by a furrow of rough bone. In the human femur it is 

 faintly marked oft" by a shallow groove in the cartilage, best seen in a recently 

 opened knee-joint. Some anatomists attribute these grooves in the cartilage to the 

 pressure of the semilunar fil)ro-cartilages. 



The angle Avhich the neck of the femur forms with the shaft measures at birth, 

 on an average, 160°. In the adult it varies from 110° to 140°; hence the angle 

 decreases greatly during the period of growth. \¥hen once growth is completed, 

 the angle, as a rule, remains fixed. (Humphry.) 



THE PATELLA 



The patella is a sesamoid bone, somewhat triangular in shape, situated in 

 front of the knee-joint. Its anterior surface is slightly convex, and pitted with 



Fig. 162.— The Lp:ft Patella. 



Anterior surface 



Po.sterior surface 



EXTERNAL ARTICULAR FACET 



LATERAL FACET 

 FOR INTERNAL 

 CONDYLE 



FOR THE 

 PATELLAR 

 LIGAMENT 



small openings, which transmit nutrient vessels to the interior of the bone. This 



