PATELLA TIBIA. 



91 



of the adductor magnus ; and beneath the tubercle, upon the upper 

 surface of the condyle, a depression, from which the internal head 

 of the gastrocnemius arises. The outer side of the internal condyle 

 is rough and concave, for the attachment of the posterior crucial 

 ligament. 



Developement. By five centres ; one for the shaft, one for each 

 extremity, and one for each trochanter. 



Articulations. With three bones ; with the os in- Fi g- 35.* 

 nominatum, tibia, and patella. 



Attachment of Muscles, To twenty-three ; by the 

 greater trochanter, to the gluteus medius and mini- 

 mus, pyriformis, gemellus superior, obturator in- 

 ternus, gemellus inferior, obturator externus, and 

 quadratus femoris ; by the lesser trochanter, to the 

 common tendon of the psoas and iliacus. By the 

 linea aspera, its outer lip, to the vastus externus, 

 gluteus maximus, and short head of the biceps; by 

 its inner lip, to the vastus internus, pectineus, ad- li 



ductor brevis, and adductor longus ; by its middle 

 to the adductor magnus ; by the anterior part of 

 the bone, to the cruraeus and subcrurseus; by its 

 condyles, to the gastrocnemius, plantaris and 

 popliteus. 



PATELLA. The patella is a sesamoid bone, de- 

 veloped in the tendon of the quadriceps extensor 

 muscle, and usually described as a bone of the 

 lower extremity. It is heart-shaped in figure, the 

 broad side being directed upwards and the apex 

 downwards, the external surface convex, and the 

 internal divided by a ridge into two smooth surfaces, 

 to articulate with the condyles of the femur. The 

 external articular surface corresponding with the 

 external condyle is the larger of the two, and serves 

 to indicate the leg to which the bone belongs. 



Articulations. With the two condyles of the femur. 



Attachment of Muscles. To four; the rectus, crurasus, vastus 

 internus, and vastus externus, and to the ligamentum patellae. 



TIBIA. The tibia is the large bone of the -leg ; it is prismoid in 

 form, and divisible into a shaft, an upper and lower extremity. 



The upper extremity, or head, is large, and expanded on each 

 side into two tuberosities. Upon the upper surface the tuberosi- 

 ties are smooth, to articulate with the condyles of the femur ; the 

 internal articular surface being oval and oblong, to correspond 

 with the internal condyle ; and the external broad and nearly cir- 



* A diagram of the posterior aspect of the right femur, showing the lines of attach- 

 ment of the muscles. The muscles attached to the inner lip are, ^, the pectineus; 

 a 6, the adductor brevis ; and a I, the adductor longus. The middle portion is occupied 

 for its whole extent by a m, the adductor rnagnus ; and is continuous superiorly with 

 qf, the linea quadrati, into which the quadratus femoris is inserted. The outer lip is 

 occupied by g m, the gluteus maximus ; and b, the short head of the biceps. 



