322 NORMAL HISTOLOGY AND ORGANOGRAPHY. 



branched tubular mucous glands which, in the cer- 

 vix, are very large and have a tendency to become 

 sacculated. These glands extend radially as far as 

 the muscularis, and some of them may even pene- 

 trate a short distance into the muscle coat. The 

 gland ducts are lined by ciliated epithelium, while 

 in the deeper portions cilia are absent and the epi- 

 thelium becomes simple cubical, resembling a glandu- 

 lar type. Most of these glands take a tortuous or 

 spiral course, and are separated from each other by 

 an interstitial tissue composed of connective-tissue 

 cells. These cells are of the embryonic type, rich in 

 chromatin and therefore stain heavily with nuclear 

 dyes. The relative amount of interstitial and 

 glandular tissue in a normal uterine mucosa should 

 be approximately equal parts. The connective 

 tissue predominates in interstitial endometritis, and 

 the glandular tissue in adenitis. The whole uterine 

 mucosa is unusually thick and very vascular. In a 

 mature woman it is normally subject to marked 

 periodic changes resulting from menstrual condi- 

 tions, which reach a high degree of complexity in 

 case of pregnancy. The action of the cilia tend to 

 produce a downward movement of the uterine 

 secretions and, therefore, opposite to the upward 

 movement of spermatozoa. 



The Muscular Layer. The muscularis is an unusu- 

 ally thick layer of smooth muscle cells which in the 

 non-pregnant uterus measure forty to sixty mi- 

 crons, while at the end of pregnancy the cells measure 

 four hundred to six hundred microns in length. 

 These muscle cells are arranged in bundles with a 

 considerable amount of connective-tissue fibers and 



