214 



TEE MUSCLES. 



the origin of the anterior straight muscle of the thigh, from which it is 

 separated by a space filled with fat ; inwardly, with the crural vessels. It 

 passes between the vastus internus and the peotineus, to reach the 

 trochanter. 



Actions. — It is a flexor and rotator outwards of the thigh. 



4. Small Psoas Muscle. (Fig. 108, 2.) 



Synonyms. — Psoas of the loirs — Bourgelat. Sublumbo-pubialis, or sublumbo-iliaous, 

 according to Girard. (JPsoas parvus — Percivall, The lombo-iliacus of Leyh.) 



Situation — Form — Structure. — Placed at the inner side of the great psoas, 

 very much elongated, and semipenniform in shape, this muscle is terminated 

 behind by a flattened tendon, and is composed of fleshy fibres, the longest of 

 which are anterior. These fasciculi are all directed backwards and outwards 

 to gain the tendon. 



Attachments. — 1, To the bodies of the three or four last dorsal, and to all 

 the lumbar vertebrse, by the anterior extremity of its fleshy fibres ; 2, To 

 the ilio-peetineal eminence and the lumbo-iliac aponeurosis, by the posterior 

 extremity of its tendon. 



Relations. — By its inferior face with the pleura, the superior border of the 

 diaphragm, the aorta or posterior vena cava, and the great sympathetic 

 nerve ; by its upper face, with the psoas magnus. It is traversed, near its 

 vertebral insertions, by numerous vascular and nervous branches. 



Actions. — It flexes the pelvis on the spine, when the loins are the fixed 

 point ; but should the pelvis be fixed, it arches or laterally inclines the lumbar 

 region. It is also the tensor muscle of the lumbo-iliac aponeurosis. 



^'-- '°^- 5. Square Muscle of the Loins. 



(Fig. 109, 1.) 



Synonyms. — Saero-cosfalis — 

 Girard. (Sacro-lumbalis — Peroivall. 

 Quadratus lumborum of Man.) 



Situation — Form — Structure 

 — Attachments. — This muscle is 

 comprised between the trans- 

 verse processes of the lumbar 

 region and the great psoas, and 

 is elongated from before to be- 

 hind, flattened above and below, 

 and divided into several very 

 tendinous fasciculi. The prin- 

 cipal fasciculus, situated out- 

 wardly, takes its origin from 

 the sacro-iliac ligament, near 

 the angle of the sacrum, and ex- 

 tends directly forward to gain 

 the posterior border of the last 

 rib, after being attached by its 

 upper face to the summits of the 

 transverse processes of the lum- 

 bar vertebrffi. The other fasci- 

 culi are ■ longer as they are an- 

 terior; they leave the internal 

 border of the first, and are directed obliq^uely forward and inward, to be 



DEEP MUSCLES OP THE SUBLUMBAR REGION. 



Quadratus lumborum ; 2, 2, IntertransTersales ; 

 3, Small retractor muscle of the last rib — a de- 

 pendent of the small oblique of the abdomen. 



