36 LABORATORY DIRECTIONS 



Action: to aid the biceps femoris. 



5. Caudo-femoralis. — This is partly covered by the anterior 

 border of the biceps femoris. It originates from the transverse 

 processes of the second and third caudal vertebrae. The fibers 

 converge, and about half way down the thigh end in a slender 

 tendon, by means of which this muscle is inserted on the lateral 

 border of the patella. 



Action: to abduct the thigh; to extend the shank. 



6. Gluteus Maximus. — This short muscle originates ante- 

 rior to the proximal end of the caudo-femoralis from the trans- 

 verse processes of the last sacral and first caudal vertebrae and 

 from dorsal fasciae. The fibers converge and are inserted just 

 below the great trochanter. The fibers also frequently inter- 

 mingle with the fibers of the next muscle, the tensor fasciae latae, 

 making it difficult to find the exact boundary of the muscle. 



Action: to abduct the thigh. 



7. Tensor Fasciae Latae. — Cut the sartorius muscle 

 through the middle. Under this and extending around to the 

 lateral side of the thigh is a heavy, glistening fascia, the fascia 

 lata (lata, wide). Slit it lengthwise on each side, being careful 

 not to Injure the quadriceps femoris muscle which lies under- 

 neath. Probe under the fascia and trace It to its insertion on 

 the patella. The proximal end of the fascia lata Is attached to a 

 triangular muscle, the tensor fasciae latae, which originates partly 

 from the outer ventral border of the ilium, and partly from the 

 fascia covering the next muscle, the gluteus medlus. 



Action: to stretch the fascia lata (as its name implies) and 

 to extend the shank. 



8. Gluteus Medius. — This is the heavy muscle anterior 

 to the gluteus maximus and largely covered by the tensor fasciae 

 latae. It originates from the dorsal half of the lateral surface 

 of the ilium, from dorsal superficial fasciae, and from the tips 

 of the transverse processes of the last sacral and first caudal 

 vertebrae. The fibers converge and join a large central tendon 

 inserted on the great trochanter of the femur. 



Action: to abduct the thigh. 



Deep Muscles of the Thigh 



To expose the deeper muscles, cut through the middle of the 

 tensor fasciae latae and caudo-femoralis and pin back the proxi- 



