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HANDBOOK OF PHYSIOLOGY. 



surrounded by unstriped muscular tissue. In the intermediate portion 

 many large veins run amongst the bundles of muscular tissue. Many 

 mucous glands, glands of Littre, are present. 



(b.) The corpora cavernosa, a true erectile structure, consist of a 

 matrix, formed of trabecula3 cerva, made up chiefly of unstriped muscle- 

 fibres, which run in all directions from the fibrous sheath, and from the 

 septum, which separates the two corpora cavernosa, intermixed with con- 

 nective tissue, and a few elastic fibres. The matrix is arranged in 

 bundles, and thus form a spongy tissue, lined everywhere with endothe- 

 lium, into the interstices of which, the venous sinuses, the venous blood 

 passes. The trabeculse thus constitute the greater part of the substance 

 of each corpus cavernosum. The venous sinuses anastomose with each 

 other to form plexuses. The arteries run in the muscular trabeculae. 



(c.) The corpus spongiosum urethrae consists of an inner portion or 



FIG. 434. Erectile tissue of the human penis, a, fibrous trabeculae with their ordinary capil- 

 laries; 6, section of the venous sinuses; c, muscular tissue. (Cadiat.) 



plexus of longitudinal veins, and of an outer or really cavernous portion 

 identical in structure with that which has just been described. The 

 lymphatics of the penis are very numerous, both superficially and also 

 around the urethra. They join the inguinal glands. 



The nerves, derived from the pudic nerves and hypogastric plexus, 

 are distributed to the skin and mucous membrane and to the corpora 

 cavernosa and spongiosum respectively. The nerves are provided with 

 end bulbs and Pacinian corpuscles in the glans penis, and form also a 

 dense subepithelial plexus. 



Coiuper's glands, are two small glands the ducts of which open into 

 the bulbous part of the urethra. They are small round bodies, of the 

 size of a pea, yellow in color, resembling the sublingual gland; in struc- 

 ture they are compound tubular mucous glands. 



The Prostate Gland. The prostate is situated (Fig. 435) at the 

 neck of the urinary bladder, and incloses the commencement of the 



