PRACTICAL ANATOMY. 



oblique folds. The entire arrangement is designated the 

 arbor vitaB uterina. The cavity of the body is triangular, 

 flattened from front to back, and communicates with the 

 cavity of the cervix at the inferior angle by the ostium 

 internum. The superior angles lead into the Fallopian 

 tubes, the orifices being each about the diameter of a 

 bristle. The anterior and posterior walls are in contact. 

 The uterus has three coats, serous, muscular, and 

 mucous. The serous coat is derived from the peritoneum, 

 which invests the posterior surface of the body, passes over 

 the fundus, and descends as far as the upper half of the 

 anterior surface of the body, whence it is reflected on the 

 bladder. The muscular coat, composed of involuntary 



fibres, is about one-half 

 inch thick, and disposed 

 in three layers, the ex- 

 ternal consisting of a 

 plane of fibres, which 

 cover the organ. These 

 fibres converge at the 

 angles and form the 



round ligaments, some fibres passing over the Fallopian 

 tubes and the ligaments of the ovary. The superficial 

 plane of muscular fibres is an erectile plane, and assists in 

 disposing the organ in a position favorable to fecundation. 

 The middle layer is thick and irregular in distribution. 

 The inner layer consists of two spiral laminae arranged 

 around the superior angles and the openings of the 

 Fallopian tubes, for which they form a sort of sphincter. 

 The mucous coat adheres closely to the muscular 

 coat ; it is continuous with the mucous membrane of the 

 Fallopian tubes and the vagina. In the cavity of the body 

 it is ciliated, but only a few ciliated epithelia are found in 

 the cavity of the cervix, where the prevailing epithe- 



