UTERUS. 253 



the ciliary current moving toward the mouth of the gland. A 

 basal membrane (membrana propria) with a double contour 

 limits this row of cells on the side toward the tunica propria, 

 and is a continuation of the basal membrane of the surface 

 epithelium. The glands probably possess no secretory function. 



The mucosa of the cervix uteri shows some distinguishing 

 features. The surface is thrown into folds, known as tlie plicce 

 palmatce. The mucous membrane is thicker and firmer, and 

 possesses much higher cylindrical cells than the corpus uteri. 

 In the region of the external os it passes over into a stratified 

 pavement epithelium with papillae beneath. After repeated 

 pregnancies this pavement epithelium covers also the lower 

 part of the cervix. The mucosa of the cervix contains, besides 

 the glands already described, numerous glands which secrete 

 mucus (glandules cervicales uteri). Often the mouths of the 

 glands become closed and there are formed retention cysts, con- 

 taining a quantity of mucoid material and reaching the size of 

 a pea. These were formerly known as ovula Nabothi 



A submucosa in the uterus cannot be made out. The 

 mucosa lies directly on the muscularis, and the glands reach 

 down so as to touch the muscle coats. The latter is the 

 thickest layer of the uterus, and is made up of long, spindle- 

 shaped, smooth muscle elements. In the non-pregnant uterus 

 these are 40-60 a long, while at the end of pregnancy they 

 reach a length of 300-600^. They are arranged in bundles, 

 mostly running concentrically around the blood-vessels. The 

 whole muscle layer, however, can be divided roughly into layers, 

 which in the adult are by no means distinctly separated from 

 one another. The exact disposition of these layers has been the 

 <3ause of much discussion, and there have been many ideas ad- 

 vanced with regard to this subject. In general, three layers can 

 be made out: 1, a longitudinal inner layer (stratum mucosum); 

 2, a middle circular layer of bundles closely associated with the 

 blood-vessels (stratum vasculare); and 3, an outer layer, in 

 which the bundles run both longitudinally and circularly. 

 The latter layer can be divided into two parts : an inner layer 

 of mixed longitudinal and circular fibres (stratum supravascu- 



