OF THE UPPER EXTREMITY. 465 



tendinous point of the perinaeum, where it blends with the External sphincter ani. 

 Its fibres pass forward on each side of the vagina, to be inserted into the corpora 

 cavernosa of the clitoris, a fasciculus crossing over the body of the organ so as to 

 compress the dorsal vein. 



Nerve-supply. The perineal branch of the internal pudic. 



Actions. It diminishes the orifice of the vagina. The anterior fibres contribute 

 to the erection of the clitoris, as they are inserted into and are continuous with the 

 fascia of the clitoris ; compressing the dorsal vein during the contraction of the 

 muscle. 



The Erector clitoridis resembles the Erector penis in the male, but is smaller than 

 it. It covers the unattached part of the crus clitoridis. It is an elongated muscle, 

 broader at the middle than at either extremity, and situated on either side of the 

 lateral boundary of the perinaeum. It arises by tendinous and fleshy fibres from 

 the inner surface of the tuberosity of the ischium, behind the crus clitoridis from 

 the surface of the crus, and from the adjacent portion of the ramus of the ischium. 

 From these points fleshy fibres succeed, which end in an aponeurosis, which is 

 inserted into the sides and under surface of the crus clitoridis. 



Nerve-supply. The perineal branch of the internal pudic. 



Actions. It compresses the crus clitoridis and retards the return of blood 

 through the veins, and thus serves to maintain the organ erect. 



The triangular ligament (deep perineal fascia) in the female is not so strong as 

 in the male. It is attached to the pubic arch, its apex being connected with the sym- 

 physis pubis. It is divided in the middle line by the aperture of the vagina, with 

 the external coat of which it becomes blended, and in front of this is perforated 

 by the urethra. Its posterior border is continuous, as in the male, with the deep 

 layer of the superficial fascia around the Transversus perinaei muscle. 



Structures between the Two Layers of the Triangular Ligament. The subpubie 

 ligament above, the dorsal vein of the clitoris, the urethra and the Compressor 

 urethrje muscle, the glands of Bartholin and their ducts ; the pudic vessels and 

 the dorsal nerve of the clitoris ; the artery of the bulbi vestibuli, and a plexus 

 of veins. 



The Compressor urethrae (eonttrietor urethra; or deep transversus perincei) arises, 

 on each side from the margin of the descending ramus of the os pubis. The fibres,, 

 passing inward, divide into two sets ; those of the fore part of the muscle are 

 directed across the subpubie arch in front of the urethra to blend with the mus- 

 cular fibres of the opposite side ; while those of the hinder and larger part pass 

 inward to blend with the wall of the vagina behind the urethra. 



MUSCLES AND FASCLE OF THE UPPER EXTREMITY. 



The Muscles of the Upper Extremity are divisible into groups, corresponding 

 with the different regions of the limb. 



OF THE SHOULDER. OF THE ARM. 



Anterior Thoracic Region. Anterior Humeral Region. 



Pectoralis major. Pectoralis minor. Coraco-brachialis. Biceps. 



Subclavius. Brachialis anticus. 



ral Thoracic Region. Posterior Numeral Region. 



Serratus magnus. Triceps. Subanconeus. 

 Acromial Region. 



Deltoid. O F THE FOREARM. 



Anterior Scapular Region. Anterior Radio-ulnar Region. 



Subscapularis. ' "3 r^onator radii teres. 



' - \ r lexor carpi radians. 



Posterior Scapular Region. ^ ^ } p a l mar is longus. 



Supraspinatus. Teres minor. -Ji Flexor carpi ulnaris. 



Infraspinatus. Teres major. ~7. ^Flexor sublimis digitorum. 



