ANATOMY IN A NUTSHELL. 41)o 



Insertion. — Into the central tendon of the perineum. 



Action. — This muscle with its fellow fixes the central tendon. 



Nerve Supply.- — Perineal branch of internal pudic. 



Blood Supply. — Superficial perineal from internal pudic. 



Sphincter vagina. — Description.— The Sphincter vagina which surrounds 

 the orifice of the vagina is the homologue of the Accelerator mime in the male. 



Origin. — Posteriorly from the central tendinous part of the perineum 

 where it blends with the External sphincter aid. 



Insertion. — Into the corpora cavernosa of the clitoris, and a fasciculus 

 passes over the body of the clitoris to compress its dorsal vein. 



Action. — To diminish the orifice of the vagina. 



Nerve Supply. — Perineal branch of the internal pudic. 



Blood Supply. — Superficial perineal from internal pudic. 



Erector clitoridis. — Description. — This muscle is the homologue of the 

 Erector penis in the male, but is a smaller muscle. 



Origin. — From the inner surface of the tuberosity of the ischium behind 

 the eras clitoridis, and also from the surface of the eras and the adjacent por- 

 tion of the ramus of the ischium. 



Insertion. — Into the sides and upper surface of the eras clitoridis. 



Action. — To maintain the organ erect by pressing on the eras clitoridis 

 and retarding the return of blood through the veins. 



Nerve Supply. — Perineal branch of the internal pudic. 



Blood Supply. — Superficial peiineal from internal pudic. 



Compressor urethra. — (Constrictor urethra). — 



Origin. — From the margin of the descending ramus of the os pubis. 



Insertion. — The fibers from the front part of the muscle cross the sub- 

 pubic arch in front of the urethra to blend with its fellow of the opposite side, 

 while fibers from the posterior portion pass inward to blend with the walls of 

 the vagina behind the urethra. 



Action. — To expell the mine and assist in erection. 



Nerve Supply. — Perineal branch of the internal pudic. 



Blood Supply. — Superficial perineal from internal pudic. 



LESSON CLXII. 



The Perineum. (Plate CCLXIX.) 



The word Perineum is \\>n\ in three different senses. ( 1 ) il includes the 

 entire outlet of the pelvis, which extends from the apex of the sub-pubic arch 

 in front to the tip of the coccyx behind, and laterally between the tuberischii. 

 (2) Il is the part of the pelvic outlet in fnint of a line connecting the tuberi- 

 schii. This is called the true perineum, while the pari behind this line is called 

 the anal, ischio-rectal. or false perineum. (3) In the surgical and obstetrical 

 sense of the word the term may include in the female all the deeper par t between 

 the posterior wall of the vagina and the anterior wall of the ledum. Tin- is 

 called the perineal body. 



