THE THORAX AND THORACIC VISCERA. 89 



Deep perinaeal interspace, 1105-6. (1082-3) 



Contents: (i) Membranous urethra, 1074. (1052) 



(2) Cowper's glands. 



(3) Internal pudic arteries. 



Artery of the bulb, 610-11. (598-9) 



(4) Pudic veins. 



(5) Pudic lymphatics. 



(6) Dorsal nerve of the penis. 



(7) Transversus perinaei profundus, or deep transversus perinsei or 

 compressor urethrae. 



Muscular division of pudic nerve, 858. (838) 

 Superior or deep triangular ligament, 1106. (1083) 



Reflect the ischio-rectal fascia from the parietal surface of the levator ani muscle ; the muscle will be 

 considered again at a later period of the dissection. 



Levator ani muscle, 1099-1100. (1075) 

 Female External Genitals and Perinaeum. 



To expose the perinaeum for dissection, draw the subject to the end of the table, flex the thigh and leg, 

 and bind the palm of the hand over the dorsal surface of the foot. A slender stick placed between the 

 knees will keep the thighs separated. The pelvis should be raised on a block. 



Female external genitals, 1156-7-8-9. (1132-4-5) ; also, 1076-7. (1053-4) 

 Labia majora. Labia minora or nymphae. Vestibule. 

 Vaginal orifice, hymen, carunculae myrtiformes. 

 Fourchette and fossa navicularis. 

 Examination per vaginam. 

 The perinaeum, 1150-1. (1126) 

 Bony boundaries. 



Two triangles: (i) Anterior or urethral. 

 (2) Posterior or rectal. 



The rectum and vagina should be moderately distended with tow, and the orifice of each closed by 

 stitching together the lateral margins. 



The perinaeum. The outlet of the pelvis, 1096. (1072-3) 

 Perinaeum proper, fascia of Colles, 1103. (1080) 

 The female perinaeum, 1107. (1083) 



The ischio-rectal region, 1097. (1074) 



Make elliptical incisions around the margins of the vagina and anus-; make a median incision through 

 the intervening space, from the pubis to the end of the sacrum. Make a transverse incision passing 

 just in front of the tuberosities of the ischium. Carefully reflect the skin and expose the superficial 

 fascia. In the urethral triangle the superficial fascia consists of two layers, a superficial layer and a 

 deeper layer, or fascia of Colles. The deeper layer, or fascia of Colles, turns around the posterior bor- 

 der of the superficial transverse perinaei muscles, and blends with the posterior border of the triangular 

 ligament, not extending over the rectal triangle. The superficial layer of the fascia should now be 

 removed, carefully preserving the deeper layer, or fascia of Colles. In the rectal triangle the sphincter 

 ani and the superficial vessels and nerves will be exposed. 



Sphincter ani externus, action, 1097-8. (1074) 



Dissect out the fat from the ischio-rectal fossae, and expose the haemorrhoidal vessels and nerves. 



Care should be exercised not to injure the fascial boundaries of the ischio-rectal fossae. 



Ischio-rectal fossae, 1102-3. ( I0 9?) 



Anterior recess, posterior recess. 



Contents. 



The obturator fascia, 1098-9; Fig. 648. (1075) 

 Lower or ischio-rectal segment. 



Ischio-rectal or anal fascia, 1102; Fig. 648. (10779) 

 External or inferior haemorrhoidal branches, 609. (597) 

 Inferior haemorrhoidal nerve, 858. (838) 

 Perinaeal branch of fourth sacral nerve, 853. (834) 

 Superficial lymphatics of the perinaeum, 700. (685) 

 Fascia of Colles, 1103-4. (1080-1) 



Divide the fascia of Colles and reflect it, exposing the structures in the superficial perinaeal inter- 

 space, Figs. 654 and 656. 

 7 



