494 



ANATOMY IN A NUTSHELL. 



The ischio-rectal fossae are situated on each side of the lower end of the 

 recutm, having on the outer side of each fossa, the tuberosity of the ischium, 

 The ischio-rectal fossa is in the form of a pyramid with its apex corresponding 

 to the junction of the Levator ani and Obturator muscles. Its base is between 

 the anus and the tuberischii. It is bounded on the inner side by the Sphincter 

 ani. Levator ani. and Coccygeus muscles; and behind by the edge of the Gluteus 

 maximus and the great sacro -sciatic ligament. It is the site of abscesses 

 and is filled with a mass of adipose connective tissue. (Plate CCLXX.) 



THE FAsei.K OF THE PERINEUM ARE: 



1. The superficial layer of the superficial fascia, which is continuous with 

 the sub-cutaneous fascia of the thighs, is thick and loaded with fat. This is 

 the lowest of all the fascia of the perineum. 



PLATECCLXII. 



ORBITAL PROCESS 

 ORBITAL SURFACE 



SPHENOIDAL SURFACE 



POSTERIOR NASAL SPINE 



AZYGOS UVULAE 



The Palate Bone, Posterior View. 



2. The deep layer of the superficial fascia is called Colles' fascia. It is 

 not thick, but very strong. It is attached posteriorly to the perineal ledge. 

 anteriorly it becomes continuous with the external fascial investment of the 

 scrotum ami the fascial covering of the penis. It extends laterally to the rami 

 of the pubis ami ischium. Some anatomists call this fascia the anterior 



LEAFLET OF THE TRIANGULAR LIGAMENT. 



3. Tin' anterior Layer of the deep perineal fascia is triangular in shape like 

 Colles' fascia,being bounded on either side by the ramus of the pubis and ischium 



and extending in from from the pubic arch and sub-pubic ligament to the per- 

 ineal Ledge p0Steri6rly. Some anatomists call this THE MIDDLE LEAFLET OF 

 'IH1-; TRIANGUL \l< LIG V.MENT. 



4. The posterior layer of the deep perineal fascia is called by some anato- 

 mists THE POSTERIOR LEAFLET OF THE TRIANGULAR LIGAMENT and has the same 

 attachments as the middle leaflet of the triangular ligament. 



