220 MYOLOGY, OR ANATOMY OF MUSCULAR SYSTEM 



The common femoral vessels are surrounded by the funnel- 

 shaped crural sheath, made of transversalis fascia in front and 

 iliac fascia behind; it is divided into three compartments- 

 outermost for the artery, middle one for the vein, and inner- 

 most contains a lymphatic gland and fat, and when distended 

 by a femoral hernia is the crural canal, % to If inches (14 to 

 34 mm.) long. The crural ring (upper opening of the canal) 

 is closed by the septum crurale. 



THE ILIAC REGION 



1. M. Qaadratus Lumborum. A quadrilateral muscle placed 

 between the last rib and the pelvis. Origin, iliolumbar liga- 

 ment, external lip of the crest of the ilium for 2 inches, from 

 two, three, or four lumbar transverse processes by fleshy slips 

 passing up anteriorly (Gray says this is a separate portion); 

 insertion, inner half of last rib and upper four lumbar trans- 

 verse processes. 



Nerves. Last dorsal and upper lumbar. 



Actions. Lateral flexor or both may extend the spine. 

 Draws down the last rib, giving fixed point for the diaphragm, 

 and aids inspiration (Quain); muscle of forced expiration 

 (Henle). Fixed above, draws pelvis to one side, or both draw 

 it forward. 



2. M. Iliopsoas. It has a broad outer head, iliacus, and 

 a narrow inner head, psoas magnus. 



Iliacus. Origin, upper half of the iliac fossa down as far 

 as the anterior inferior spine, posteriorly from ala of the sacro- 

 iliac and iliolumbar ligaments. Inserted mostly into tendon 

 of the psoas; outermost fibers pass to the femur in front of 

 and below the small trochanter. 



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 dorsal 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 



