UTERUS (NORMAL ANATOMY). 



625 



altered in texture after the whole of the cer- 

 vix has been destroyed by carcinomatous 

 ulceration. 



inner surfaces are not in immediate contact 

 like those of the uterine body ; but diverge 



On the other hand it is the part slightly to enclose a flattened spindle-shaped 



cavity, termed the canal or cavity of the 

 Fig. 424. cervix. 



The situation of the widest or central part 

 of this canal is indicated by an external late- 

 ral bulging of the walls of the uterine neck. 

 The posterior part of the cervix receives a 

 loose investment of peritoneum ; but the 

 whole or the greater portion of its anterior 

 wall, as well as the lower or vaginal portion, 

 is uninvested by that membrane. 



The vaginal portion. The lower extremity 

 of the cervix (fig. 424. below, c c) projects 



Fig. 425. 



Section showing the regional divisions of the uterus 

 (Outlined ad Nat.") 



from which polypi, that are not cervical in 

 their origin, most frequently arise; and it is 

 very commonly the seat of those large hyper- 

 trophic growths of the uterine tissue, which 

 are usually termed fibrous tumours. The 

 fundus is also the part to which the upper 

 portion of the placenta is most frequently 

 attached. 



The body is included between the line 

 above indicated, and another, B B, drawn 

 through the narrowest part of the organ, or 

 that point at which the tapering lateral walls 

 of the uterus approximate in the greatest de- 

 gree before they again diverge to pass into 

 the cervix. The body of the uterus consti- 

 tutes its principal portion. It is that part 

 which, more than any other, expands to in- 

 vest the ovum. It is freely supplied with 

 blood-vessels, which, entering by the lateral 

 border, ramify abundantly through the ante- 

 rior and posterior walls. These walls are 

 usually half an inch in thickness. They are 

 separated from each other by a scarcely appre- 

 ciable cavity, to be hereafter described, lying 

 between the inner surfaces of the parietes. 

 The extreme narrowness of this cavity is 

 shown in Jigs. 427 430., which represent 

 transverse sections of the uterine body, at 

 various points between the fundus and in- 

 ternal OS. 



The cervix, or neck, (fig. 424. B c), is a 

 cylindriform prolongation of the uterine bodv, 

 to which it serves as an excretory conduit. It 

 is composed in part of tissues similar to those 

 of the body, hut the arrangement of these is 

 materially different. The walls of the cervix 

 measure 4'" in average thickness. Their 

 Supp. 



Os uteri, and vaginal portion of the cervix. 

 (Ad Nat.) 



Virgin. 



into the vagina in the form of a flattened cone. 

 The length of this conical projection is about 

 4"'. It is of unequal diameter. Transversely 

 it measures 11'" 12"' at the base, and 6"' 

 7"' at the apex ; but its antero-posterior dia- 

 meters are only 1'" 8'" at the base, and 5"' at 

 the apex ; so that a section of this part will 

 represent an ellipse. Around the base of this 

 conical portion the walls of the upper end of the 

 vagina are attached. The vaginal attachment 

 constitutes the line of demarcation between 

 the lower or vaginal and the upper or supra- 

 vaginal division of the cervix. It should be 

 observed that the end of the cervix does not 

 lie, as is commonly supposed, exactly at the 

 extremity of the vaginal canal, but that it 

 projects into its upper wall, so that the upper 

 vaginal wall is shorter than the lower by the 

 whole antero-posterior diameter of the cervix 

 (fig. 426. and 433.). This explains the diffi- 

 culty which is sometimes experienced in 

 bringing the cervix into view when a tubular 

 speculum is employed, the sides of which are 

 all of equal length. There can be no doubt 

 that this peculiar position of the extremity of 

 the cervix prevents the part from suffering 

 injury in coitu, because the impulse of the 

 intromittent organ is received upon the end 

 of the vagina, and is distributed upon the 

 adjacent parts, through the intervention es- 

 pecially of the utero-sacral ligaments. See 

 further, p. 689. 



At the apex of this conical mamelon is 

 observed a transverse fissure 3"' 4'" in 

 length. This is the lower or terminal orifice 

 of the cervical canal, the os externum uteri, 

 fig. 425., as distinguished from the os inter- 

 s s 



