MUSCLES AND FASCIA OF UPPER EXTREMITY 147 



abdomen. The structures to be seen are the anus 

 (outlet of rectum), the scrotum in the male, and the 

 vagina in the female. 



The perineum is covered by skin, superficial fascia 

 divisible into a superficial layer, and a deep layer 

 called Colles'. 



The deep perineal or subpubic fascia or triangular 

 ligament of the urethra is stretched across the subpubic 

 arch and consists of two layers; the inferior layer 

 extends back to the central point of the perineum, 

 attached to the ischiopubic rami, connected at its 

 base with the other layer, and continuous with the 

 recurved margin of the superficial perineal fascia. 



The superior (deep) layer consists of right and left 

 lateral halves, separated in the middle line by the 

 urethra close to the prostate, and continuous on each 

 side with the fascia covering the obturator internus 

 muscle. The levator ani muscle is between this layer 

 and the rectovesical fascia. 



MUSCLES AND FASCLE OF THE UPPER 

 EXTREMITY 



Muscles and Fasciae of the Shoulder 



The Acromial Region. The deep fascia is strong and 

 tendinous over the back of the deltoid and infra- 

 spinatus; the infraspinatus fascia covers the teres 

 minor and splits at the posterior border of the deltoid, 

 a deep layer passing to the shoulder-joint under that 

 muscle, a superficial layer to the spine of the scapula 

 over the muscle. 



Deltoid. Origin in three portions : an anterior from 

 the front of the outer third of the clavicle, a middle 

 from the point and outer edge of the acromion, a pos- 

 terior from the lower border of the scapular spine and 

 triangular surface at its inner end, and from the infra- 



