URETHRA. 



1255 



cording to the condition of the canal. If 

 any obstruction exists either at the prostatic 

 part, or in any other situation, the force, size, 

 shape, or direction, of the urinary stream is 

 altered according to circumstances; and hence, 

 by inspection during the passage of the urine, 

 we can often arrive at a satisfactory conclu- 

 sion of the nature of the obstruction without 

 the introduction of instruments. 



When, however, the seminal secretion is to 

 be expelled, the condition of the urethra is 

 totally altered, and the canal is diminished in 

 diameter but increased in length from the 

 general distension of the penis with blood, 

 and the consequent erection of the organ. 

 The direction of the anterior part of the 

 urethra is altered and straightened to the 

 utmost ; the prostatic part is raised by the 

 action of the levator prostate, and thus forms 

 a gentle inclination with the membranous 

 part'; and the fluid oozing through the vasa 

 ejaculatoria is collected in the bulb, which 

 thus becomes distended. Although it is not 

 possible to see what is going on, yet we may 

 imagine that at this period of the orgasm a 

 sort of vermicular movement takes place, and 

 that successive contractions and relaxations 

 of the muscular apparatus of this part of the 

 genitourinary system occur. Thus I appre- 

 hend that the sphincter vesicas effectually 

 closes up the orifice of the bladder, whilst 

 the levator ani and compressor prostatae ex- 

 pel the contents of the vesiculae and the pro- 

 state : and further, that after the bulb is dis- 

 tended with fluid, the acceleratores urinae con- 

 tract with considerable and successive effort, 

 and at this moment the muscles surrounding 

 the membranous part contracting prevent any 

 retrogression of the seminal and vesicular se- 

 cretions, and thus the contents of the urethra 

 are forcibly expelled through the anterior part 

 of the canal, now made rigid by the distension 

 of the penis, and by the contraction of its 

 own peculiar tissue, a forcible muscular 

 effort being required to expel the somewhat 

 inspissated fluids. The erection of the caput 

 gallinaginis, by the distension of its erectile 

 tissue, has considerable influence in closing 

 up the prostatic part of the urethra, and thus 

 assists in preventing its retrogression into the 

 bladder. 



The action of the acceleratores urmce in 

 expelling the contents of the urethra in the 

 venereal orgasm, has been denied on the high 

 authority of Cuvier. Kobelt believes that 

 their sole action is to compress the bulb, 

 and thus to force the blood onwards into the 

 glans penis, and to increase the turgescence 

 of this body ; but that they have no direct 

 influence either in accelerating the flow of 

 urine as their name implies, or in the evacua- 

 tion of the urethra during the act of copu- 

 lation.* 



There are few parts with which the consti- 

 tution has a more close sympathy than the 



* Die Mannlichen untl Weiblichen Wollust- 

 orgtine des Menschen, &c. Von Kobelt. Frei- 

 burg, 18-14. 



urethra : this is evinced by the general disturb- 

 ance of health under the influence of diseases 

 of this canal : thus, in inflammation from 

 gonorrhoea, or even common causes, irritative 

 fever is set up, persisting frequently as long as 

 the disease lasts. So also, when in suspected 

 or actual stricture, a bougie is passed along 

 the canal, faintness occurs, followed by a class 

 of symptoms resembling those of the suc- 

 cessive stages of an ordinary intermittent. 

 When nice-ration takes place, a similar train 

 of s\ mptoms sets in. The same is also fre- 

 quently remarked during the passage of stones, 

 or fragments of stone, along the canal. This 

 sympathy must be referred to the general 

 nervous supply derived from the filaments of 

 the sympathetic and cerebro-spinal axis. The 

 sensibility of the urethra is not the same 

 throughout ; it is evidently more intense at 

 the commencement, in the prostatic and mem- 

 branous portions, and near the meatus, than 

 in the spongy part generally. The pain, how- 

 ever, accompanying diseases of the urethra is. 

 commonly referred to the meatus, in obedi- 

 ence to the well-known law, that when irrita- 

 tion of any of the mucous surfaces produces 

 pain, this is principally felt at the point where 

 the mucous and cutaneous systems blend into 

 one another, namely at the outlet of the 

 mucous canal. 



DEVKLOPMENT. The development of the 

 male urethra is a subject of considerable 

 interest both in a physiological and patho- 

 logical point of view, as a comprehension of 

 the phenomena attending it enables us to offer 

 a ready explanation of those curious mal- 

 formations to which this canal is not un- 

 frequently liable. 



For the description of the development of 

 the intra-pelvic portion of the urethra from 

 the uro-genital sinus, the reader is referred 

 to the article PROSTATE, in which the separa- 

 tion between the bladder and rectum in the 

 male, and the bladder, rectum, and vagina of 

 the female, is considered ; and we have, there- 

 fore, now only to trace the growth ana exten- 

 sion of that portion of the urethra which 

 traverses the body of the penis. 



Up to the end of the fifth or beginning of 

 the sixth week, the external organs of ge- 

 neration in the male resemble those of the 

 female, and a common opening or cloaca exists, 

 into which the rectum, bladder, and genital 

 organs terminate. At the anterior part of 

 this common outlet a small projection is 

 formed, presenting a concavity below, along 

 which there runs a superficial groove towards 

 the anus. This corresponds to the clitoris in 

 the female, and the penis in the male. A 

 slight enlargement now takes place at the 

 extremity, which becomes the glans. In the 

 female the two sides of the groove begin to 

 swell out, and become the labia majora, A 

 separation now takes place between the open- 

 ings of the anus and vagina, and the perinaeum 

 begins to be formed. The opening of the 

 uro-genital canal is a small aperture in front 

 of the anus, at the extremity of a slit, which 

 proceeds as far as the root of the penis or 



