146 MUSCLE TISSUE 



Psoas Magnus (or Major). Origin, by five fleshy 

 slips from anterior surfaces and lower borders of the 

 lumbar transverse process, and by a series of processes, 

 each from a disk and contiguous margins of two bodies; 

 the highest is attached to the last thoracic and first 

 lumbar, and lowest to the fourth and fifth lumbar 

 and intervertebral substance between them; fibers 

 also come from the sacroiliac joint and sacrum. These 

 attachments are connected with arches passing over 

 the middle of the vertebrae. The fibers all unite to a 

 thick, long muscle running along the brim of the 

 pelvis, passing under Poupart's ligament, and inserted 

 by a tendon into the small trochanter; separated by 

 a bursa. 



The common tendon is also separated from the cap- 

 sule of the hip by a bursa. 



PSOAS PARVUS (OR MINOR). Placed on the surface 

 of the psoas magnus; rises from the bodies of the last 

 thoracic and first lumbar vertebrae and disk between; 

 ends in a flat tendon merged into the iliac fascia and 

 inserted into the iliopectineal line and eminence. 

 When present its origin is variable; was absent on 

 both sides in 40 per cent, of cases. 



The Muscles and Fasciae of the Perineum 



These are the structures wiiich enclose the space 

 between the rami of the pubes and ischii on both 

 sides and the pubic arch and subpubic ligament in 

 front, while they are bounded behind by a line extend- 

 ing transversely between the anterior edge of the 

 tuberosities of the ischii on both sides. The space 

 in front of this line is termed the perineum, and behind 

 the line, the space in front of the coccyx, is called the 

 ischiorectal region; this space is bounded on the sides 

 by the gluteus maximus muscles. 



The perineum can be demonstrated only by having 

 the subject on its back with the limbs flexed on the 



