THE THIGH 179 



its deep surface processes pass off which penetrate the limb and 

 constitute sheaths for the muscles and other structures which 

 compose it. Three of these, which are especially strong, form 

 distinct septa or partitions which reach the femur and are 

 attached to the linea aspera on its posterior aspect. These 

 partitions are termed the intermuscular septa, and are so dis- 

 posed that they intervene between the three great groups of 

 muscles in this region. The septum intermusculare laterale is 

 placed between the- extensor muscles in the anterior area 

 of the thigh and the hamstring muscles in the posterior 

 region ; the septum intermuscular mediale intervenes between 

 the extensor muscles and the adductor muscles in the medial 

 region ; whilst the septum intermusculare posterius, weak and in- 

 conspicuous in comparison with the other two, is interposed 

 between the adductor and the hamstring muscles. These 

 partitions will be disclosed in the subsequent dissection. In 

 the meantime, merely observe that the medial and the 

 lateral septa show on the surface of the fascia in the lower 

 part of the thigh as white lines. By means of the three septa 

 the thigh is divided into three osteo-fascial compartments, viz. 

 an anterior, containing the extensor muscles and the femoral 

 nerve ; a posterior, holding the hamstrings and the sciatic 

 nerve ; and a medial, for the adductors with the obturator 

 nerve (Fig. 67). 



Bursae Patellares (Patellar Bursse). Several mucous bursae 

 are situated in the patellar region, those which lie superficially 

 may be investigated now and the more deeply placed bursae 

 should be examined at later stages of the dissection as 

 opportunity occurs. 



The bursae are (i) The subcutaneous prepatellarbursa which 

 lies immediately beneath the skin opposite the distal part 

 of the patella. (2) The subfascial prepatellar bursa situated 

 between the fascia lata superficially and the proximal part of 

 the patella and the adjacent part of the tendon of the 

 quadriceps deeply ; this bursa may be displayed by an incision 

 made through the fascia lata in the area indicated. (3) The 

 subtendinous prepatellar bursa lying between the superficial 

 fibres of the tendon of the quadriceps and the periosteum of 

 the anterior surface of the patella. (4) The suprapatellar bursa. 

 This lies proximal to the patella, posterior to the tendon 

 of the quadriceps and anterior to the distal part of the 

 anterior surface of the femur ; it usually communicates with 



i 12 a 



