THE URO-GENITAL SYSTEM 



layers of the oviduct, which layers later develop the muscular 

 structure and the connective tissue. The epithelium and its 

 derivatives, which represent the glandular structures, are formed^ 

 from the walls of the old Mlillerian duct. Thus the two sets of 

 tissues, having different origins, likewise have different functions. 

 The epithelium is concerned entirely with secretion, and the deriva- 

 tives of the mesenchyme are con- 

 cerned with supporting and muscu- 

 lar function. 



To summarize, six layers of tissue 

 occur in the funnel region, namely, 

 an outer serous covering, an outer 

 longitudinal muscular layer, a layer 

 of connective tissue, an inner circular 

 layer, a second layer of connective 

 tissue, and an inner mucous layer. 

 The mucous layer is made up of 

 glands, as follows. The unicellular 

 glands occur between the ciliated 

 cells of the epithelium. These glands 

 are found only in the posterior half 

 of this division of the oviduct. The 

 glandular grooves are made up of an 

 accumulation of gland cells at the 

 bottom of the grooves between the 

 secondary folds of the epithelium. 

 These are found in all parts of this 

 division except the extreme posterior 

 part. In the posterior part we find 

 the third type of glands, the tubular 

 variety. 



The second division of the oviduct, 

 as stated above, is the albumin-secreting portion. The funnel divi- 

 sion gradually merges into the second portion. These two portions 

 are distinguishable from each other. The walls of the albumin- 

 secreting portion are much thicker and the longitudinal ridges are 

 higher. This section is the longest of the five divisions, measuring 

 from 40 to 42 centimeters in length, or more than half the length 

 of the oviduct. The albumin division terminates rather abruptly 

 into the third division, the isthmus (Fig. 59, A). 



FIG. 60, A. The mucous lining of 

 the oviduct. 



E. Section of the epithelium 

 from the vagina showing unicellular 

 glands. 



F. A section from the isthmus 

 showing opening of a tubule. 



