URETHRA. 



1245 



the bulbous and membranous portions of the 

 canal.* 



Mr. Briggs observing that most of his pre- 

 decessors had examined the length of the 

 urethra after death, made a series of examina- 

 tions of the canal in the living subject; and 

 he adopted the following mode of examina- 

 tion : He introduced into the bladder a ca- 

 theter without a stilet, on the stem of which 

 was marked a graduated scale of inches and 

 fractional parts, measured from the eye of the 

 instrument. He observes, "as soon as the 

 urine begins to flow from the catheter, which 

 has only one eye, the line marked on the stem 

 corresponding with the external meatus will 

 necessarily indicate the exact length of the 

 canal, or the distance from the meatus to its 

 termination \n the bladder. Of sixty persons 

 in whom the urethra was measured thus, the 

 length was found to vary from 6f to 8 inches. 

 In eight instances, or rather less than one- 

 seventh of the whole (twenty of them being 

 persons of short stature, or not exceeding 

 5 feet 4- inches in height), the length of the 

 urethra was found to be under 7 inches. In 

 forty-five instances, or three- fourths of the 

 number, i. e. in persons of middle stature, the 

 measurement was found to be between 7 and 



8 inches, and in a few it exceeded 8. In some 

 instances of very corpulent subjects, at an 

 advanced age, the urethra was found to be 10 

 inches in length." He considers the average 

 length of the passage to be 7 or 7f inches, 

 the external parts being in a natural condition, 

 neither hanging in a loose, flabby state, nor 

 unusually retracted. Briggs found the pro- 

 portions of the various parts of the canal to 

 stand relatively thus : from the orifice to 

 the membranous part, 6 inches; from thence 

 to the bladder, 1 inch = 8^ inches. As there 

 was no stretching of the penis in the examina- 

 tions thus made, it is easy to reconcile the 

 discrepancies between Briggs's and Whately's 

 measurements. 



Of the relative length of the different por- 

 tions of the canal, M. Petrequin cites the fol- 

 lowing authorities : The prostatic portion 

 measures, according to Boyer, 15 or 16 lines ; 

 Littre, 15 lines; Ducamp and Blandin, from 

 12 to 15; Senn, 13; J. Cloquet, 15. M. 

 Petrequin agrees with Lisfranc, that the most 

 exact measurement is from 8 to 11 lines. 



Boyer estimates the length of the mem- 

 branous portion at 12 lines; Ducamp, from 



9 to 12; Blandin, at 10; Lisfranc, from 7 to 11. 

 M. Petrequin has found it to vary from 6 to 

 9 lines, when measured by its central axis ; 

 its upper surface measuring from 8 to 10 lines, 

 its under surface from 4 to 5 and sometimes 6, 

 the difference arising from the projection of 

 the bulb beneath. The mean length of the 

 prostatic and membranous portions taken to- 

 gether is, according to Malgaigne, 13 lines, 

 but it varies from 11 to 15 lines. Petrequin 



* See the review of M. Petrequin's work ( Traite 

 (TAnatomie Medico-chirurgique, *c.), in the British 

 and Foreign Medical Review, vol. xx. p. 136. 



has found it to vary from 14 to 18 and some- 

 times 20. As to the bulbous and pendulous 

 portions of the urethra, their rectilinear mea- 

 surement is 6 inches or 6 inches and 10 lines, 

 and the curvilinear 5 inches or 5 inches and 

 4 lines.* 



Diameter. In diameter, also, the urethra 

 varies according to age: thus in the young sub- 

 ject it is small ; indeed its diameter increases in 

 proportion to the age of the individual ; and 

 in the aged, partly in consequence of the flac- 

 cidity of the parts surrounding it, partly from 

 the loss of contractility in its own tissue, its 

 capacity becomes immensely increased, so 

 that it will readily admit a catheter of half- 

 an-inch bore, and the escape of fragments of 

 stone of equal size. 



Even in the infant, however, the urethra is 

 more capacious than is generally imagined, 

 and will admit a much larger sound than we 

 should a priori suppose ; a fact of no small im- 

 portance in sounding at this early period of 

 life. When the penis is erect, the urethra is 

 diminished in diameter, from the pressure of 

 the turgid veins of the spongy body, and from 

 the increased distension of its own blood- 

 vessels. 



To ascertain the diameter of the urethra, 

 and to compare it in persons of different 

 ages, Sir E. Home examined the canal in 

 two persons one of the age of 80, and the 

 other 30. 



At 80. At 30. 



At 9 lines from the meatus 



it measured - - - 5 lines 4-J lines. 

 At 4 inches 3 lines from ditto 4 4 " 



.At 6 inches from the meatus - 



(at the bulb) - - - 7 7 



At 7 inches (beginning of 



membranous part) - - 4 2 



At 7 inches 9 lines (near the 



prostate) - 5 4 



At 8 inches (beginning of 



the prostatic part) - 4 3 



At 8 inches 3 lines (the 



middle of ditto) - - 6 5 



At 81 inches (near the neck 



of the bladder) - 5 4 



Briggs directed his attention to the dia- 

 meter of the urethra in the various parts of 

 its course, and he found the dimensions ma- 

 terially altered if the urethra be injected with 

 wax or any other substance; and the result 

 of his examination throws considerable doubt 

 on the conclusions of Sir Everard Home. 

 From the casts which he made he failed to 

 discover any sudden narrowing or constric- 

 tion at the termination of the membranous 

 part of the urethra, or any resemblance in 

 the shape of the curve as represented in 

 Home's plates.-j- 



Briggs remarks, " The portion of the urethra 

 which extends from the apex of the prostate 



* Ibid. 



t From examinations I have made myself of wax 

 casts of the ui-ethra, I believe the representations of 

 Home not to be exaggerated. 



