1258 



SPLANCHNOLOGY 



ends by extrusion of the ovum through the abdominal ostium, although it is not uncommon for 

 the tube to rupture into the peritoneal cavity, this being accompanied by severe hemorrhage, 

 and needing surgical interference. 



The Uterus (Womb) (Figs. 1161, 1165, 1166). 



The uterus Is a hollow, thick-walled, muscular organ situated deeply in the 

 pelvic cavity between the bladder and rectum. Into its upper part the uterine 

 tubes open, one on either side, while below, its cavity communicates with that of 







xf?v"SSSf^^^^K'- '-;->--. \ 



POSTERIOR 

 FORNIX 



FIG. 1166. Sagittal section of the lower part of a female trunk, right segment. SM. INT. Small intestine. (Testut.) 



the vagina. When the ova are discharged from the ovaries they are carried to the 

 uterine cavity through the uterine tubes. If an ovum be fertilized it imbeds itself 

 in the uterine \vall and is normally retained in the uterus until prenatal develop- 

 ment is completed, the uterus undergoing changes in size and structure to accom- 

 modate itself to the needs of the growing embryo (see page 59) . After parturition 

 the uterus returns almost to its former condition, but certain traces of its enlarge- 

 ment remains. It is necessary, therefore, to describe as the type-form the adult 

 virgin uterus, and then to consider the modifications which are effected as a resul* 

 of pregnancy. 



