408 MUSCLES AND FASCIAE. 



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 behind the Sartorius. 



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

 its deep surface, with the Iliacus, Psoas, Rectus, Vastus Internus, anterior crural 

 nerve, sheath of the femoral vessels, Adductor Longus, Adductor Magnus, Gra- 

 cilis, 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 por- 

 tions, which have received distinct 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 out- 

 wards, to be attached to a groove above the brim of the acetabulum ; this is the 

 reflected tendon of the Rectus, it unites with the straight tendon at an acute 

 angle, and then spreads 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 posterior surface, and gradually becoming narrowed 

 into a flattened tendon, is inserted into the patella in common with the Yasti 

 and Crureus. 



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

 Medius, the Tensor Vagina3 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 

 anatomists, separate from the Rectus, under the name of the Triceps Extensor 

 Cruris; in order to expose them, divide the Sartorius and Rectus across the 

 middle, and turn them aside, when the muscles in question 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 

 trochanter, 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 arise from the tendon of the Gluteus Maximus, and from the external 

 intermuscular septum between the Vastus Externus, and short head of the 

 Biceps. The fibres form a large fleshy mass, which is attached to a strong 

 aponeurosis, 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 synovial bursa. By its deep surface, with the Crureus, some large branches 

 of the external circumflex artery and anterior crural nerve being interposed. 



The Vastus Internus and Crureus are so inseparably connected together, as to 

 form but one muscle, as which it will be accordingly described. It is the smallest 



