330 MUSCLES AXD FASCIA. 



muscle to the femoral artery should be carefully examined, as its inner border 

 forms the chief guide in the operation of including this vessel in a ligature. In 

 the upper third of the thigh, it forms, with the Adductor longus, the side of a 

 triangular space, Scarpa's triangle, the base of which, turned upwards, is formed 

 by Poupart's ligament : the femoral artery passes perpendicularly through the 

 centre of this space from its base to its apex. In the middle third of the thigh, 

 the femoral artery lies first along the inner border, and then beneath the Sar- 

 torius. 



Relations. By its superficial surface, with the fascia lata and integument. By 

 its deep surface, with the Iliacus, Psoas, Eectus, Yastus internus, anterior crural 

 nerve, sheath of the femoral vessels, Adductor longus, Adductor magnus, Graci- 

 lis, long saphenous nerve, and internal lateral ligament of the knee-joint. 



The Quadriceps extensor includes the four remaining muscles on the front of 

 the thigh. It is the great Extensor muscle of the leg, forming a large fleshy mass, 

 which covers the front and sides of the femur, being united below into a single 

 tendon, attached to the tibia, and, above, subdividing into separate portions, which 

 have received separate names. Of these, one occupying the middle of the thigh, 

 connected above with the ilium, is called the Rectus femoris, from its straight 

 course. The other divisions lie in immediate connection with the shaft of the 

 femur, which they cover from the condyles to the trochanters. The portion on 

 the outer side of the femur is termed the Vastus externus; that covering the inner 

 side, the Vastus internus ; and that covering the front of the femur, the Crureus. 

 The two latter portions are, however, so intimately blended, as to form but one 

 muscle. 



The Rectus femoris is situated in the middle of the anterior region of the thigh; 

 it is fusiform in. shape, and its fibres are arranged in a bipenniform manner. It 

 arises by two tendons ; one, the straight tendon, from the anterior inferior spinous 

 process of the ilium ; the other is flattened, and curves outwards, to be attached 

 to a groove above the brim of the acetabulum ; this is the reflected tendon of the 

 Rectus, uniting with the straight tendon at an acute angle, and then spreading into 

 an aponeurosis, from which the muscular fibres arise. The muscle terminates in 

 a broad and thick aponeurosis, which occupies the lower two-thirds of its poste- 

 rior surface, and, gradually becoming narrowed into a flattened tendon, is inserted 

 into the patella in common with the Vasti and Crureus. 



Relations. By its superficial surface, with the anterior fibres of the Gluteus 

 medius, the Tensor vaginas femoris, Sartorius, and the Psoas and Iliacus ; by its 

 lower three-fourths, with the fascia lata. By its posterior surface, with the hip- 

 joint, the external circumflex vessels, and the Crureus and Vasti muscles. 



The three remaining muscles have been described collectively by some anato- 

 mists, separate from the Rectus, under the name of the Triceps extensor cruris ; in 

 order to expose them, divide the Sartorius and Rectus muscles across the middle, 

 and turn them aside, when they will be fully brought into view. 



The Vastus externus is the largest part of the Quadriceps extensor. It arises 

 by a broad aponeurosis, which is attached to the anterior border of the great tro- 

 chanter, to a horizontal ridge on its outer surface, to a rough line, leading from 

 the trochanter major to the linea aspera, and to the whole length of the outer lip 

 of the linea aspera ; this aponeurosis covers the upper three-fourths of the muscle, 

 and from its inner surface many fibres arise. A few additional fibres come from 

 the tendon of the Gluteus maximus, and from the external intermuscular septum 

 between the Vastus externus and short head of the Biceps. These fibres form a 

 large fleshy mass, which is attached to a strong aponeiirosis, placed on the under 

 surface of the muscle at its lowest part; this becomes contracted and thickened 

 into a flat tendon, which is inserted into the outer part of the upper border of the 

 patella, blending with the great Extensor tendon. 



Relations. By its superficial surface, with the Rectus, the Tensor vaginas 

 femoris, the fascia lata. and the Gluteus maximus, from which it is separated by a 



