OSTEOLOGY. 65 



Troclilea is a smooth surface between the condyles in front 

 and articulates with the patella in front. The inferior surfaces 

 of both condyles are smooth, continuous in front, covered with 

 cartilage in the recent state, for articulation with the head of the 

 tibia. The femur articulates with three bones innominatum, 

 tibia, and patella. 



Its muscular attachments are twenty-three (23) two vasti, 

 three adductors, glutens maximus, medius, and minimus, pyri- 

 forinis, obturator externus and internus, two gemelli, quadratus 

 iVinoris, psoas inagnus, iliacus, biceps, pectineus, crureus, sub- 

 cntreus, gastrocnemius, plantaris, and popliteal. 



I is ossific centres are five three primary, one each for shaft 

 and each extremity, and one epiphysis for each trochanter. 



THE PATELLA is a flat, triangular bone, sesamoid in origin, 

 developed in the tendon of the quadriceps extensor, forming the 

 knee-cap, and entering into the formation of the knee-joint. 



The convex anterior surface is roughened by apertures for 

 nutrient vessels. 



The posterior or internal surface is divided by a vertical and 

 transverse ridge into three surfaces two smooth, articular facets, 

 for either condyle of femur above, -the outer being deeper and 

 broader, and a rough surface below (apex) for ligamentum 

 patellae. 



The supcnor border gives attachment to the rectus and 

 crureus muscles, the internal and external lateral borders to the 

 vasti internus and externus. 



It articulates with the femur. 



Its muscular attachments are four muscles rectus femoris, 

 crureus. VMS! us externus, and vastus internus. 



It is developed from a single ossific centre. 



Tin-; TIBIA, or shin-bone, extends on the internal aspect of 

 the leg from the knee to ankle, and consists of a shaft, upper and 

 lower ext remity. 



The shaft is triangular, prismoid, with the base above. 



Its anterior bonier and internal surface are subcutaneous, 

 the former forming the shin or crest of the tibia. 



The posterior surfucc presents above an tthlu/ne line for the 

 lower border of the popliteal muscle and fascia, and origin of the 

 soleus, and parts of flexor longus digitoruin and tibialis posticus 

 muscles. 



It presents just below the oblique line a nutrient canal, the 

 largest in the skeleton, directed downward. 



Its external border, or interosseous ridge, is thin, for attach- 

 ment of interosseous membrane. 



The external surface and internal borders are covered by 

 muscles. 



