548 LABORATORY MANUAL OF HUMAN ANATOMY 



(a) Levator muscle of anus (M. levator ani). 



(aa) Pubococcygeus muscle (M. pub o coccygeus). 



(ab) Iliococcygeus muscle (M. iliococcygeus). 



(b) Coccygeus muscle (M. coccygeus}. 



Remove the viscera from the pelvic cavity. Divide the ves- 

 sels and nerves connected with the viscera, the levator ani mus- 

 cle, and the pubovesical ligaments. Divide the structures hold- 

 ing the urethra and vagina to the pubic arch. Separate the 

 rectum from the sacrum and coccyx. Now study- 

 Other Pelvic Muscles and Fascia. 



(a) Obturator internus muscle (M. obturator internus). (Vide Spalte- 



holz, Fig. 373.) 



(b) Obturator fascia (fascia obturatoria). 



(c) Piriform muscle (M. piriformis). 



Rectum (Intestinum rectum). (Vide Spalteholz, Fig. 576.) 



Dissect the rectum away from the vagina and uterus. Open 

 the rectum along its anterior wall and study its 



(a) Mucous membrane (tunica mucosa). 



(aa) Transverse rectal folds (plicae transversales recti). 



(ab) Lymph-nodules (noduli lymphatici). 



In the anal part of the rectum (pars analis recti) study 



(ac) Rectal columns of Morgagni (columnae rectales [Morgagnii]). 



(ad) Hemorrhoidal ring (annulus haemorrhoidalis) . 



(b) Submucous tela (tela submucosa). 



(c) Muscular tunic (tunica muscularis). 



(ca\ Longitudinal layer (stratum longitudinale) . 



(caa) Rectococcygeus muscle (M. rectococcygeus). 

 (cb) Circular layer (stratum circular e). 



Note that the circular fibres are increased in 

 number in the base of each transverse rectal fold. 

 (cba) Internal sphincter muscle (M. sphincter ani in- 

 ternus). 



Female Urethra. 



Open the bladder along its anterior surface. Carry the in- 

 cision along the anterior wall of the urethra. Pin the urethra 

 and bladder down upon a cork dissecting-tray and study the 

 female urethra (urethra muliebris). (Vide Spalteholz, Fig. 

 642.) Compare it with the male urethra, noting differences. 



(a) External urethral orifice (orificium urethras externum). 



(b) Spongy body of urethra (corpus spongiosum urethrae). 



(c) Muscular tunic (tunica muscularis). 



