258 



NORMAL HISTOLOGY. 



cervix. The longitudinal muscle-bundles are continued beyond the uterus 

 into the oviducts and the broad, round, ovarian and utero-sacral ligaments. 

 The component fibre-cells of the uterine muscle vary in form, in some places 

 being short and broad and in others long and fusiform. 



The serous coat, or perimetrium, continuous laterally with the peri- 

 toneal investment of the broad ligament, is closely adherent to the uterine 

 muscle over the fundus and adjacent parts of the anterior and posterior surfaces. 



The blood-vessels approach the uterus between the layers of the broad 

 ligament. On gaining the muscular coat, the larger branches divide into 

 twigs that penetrate the outer layer of the myometrium and within the cir- 



Longitudinal muscle 

 Blood-vessels 



^5S^ "V 



r? -,- - ; K 



Attachment !:'_ 

 of broad <?j 

 ligament, . 



LC. & 



Circular muscle 



Mucous membrane' 



Longitudinal muscle- 



Peritoneum 



FIG. 307. Transverse section of uterus through the body. X ij. 



cular muscle break up into tortuous branches which in part pass to the 

 mucous membrane and, in conjunction with the large veins, confer a highly 

 vascular character to the stratum. Within the mucosa, the capillaries sur- 

 round the glands and form a network beneath the epithelium. The veins 

 begin in the mucosa, but within the middle of the muscular coat form large 

 tortuous channels, sections of which appear as conspicuous irregular spaces 

 between the muscle-bundles. 



The lymphatics within the mucosa are represented by a network of 

 lymph-spaces, from which stems pass through the muscular coat to join the 

 close-meshed subserous network of larger lymphatics. The efferent trunks 

 pursue various courses and communicate with the lymphatics of the neigh- 

 boring organs vagina, rectum, ovaries, and oviducts. 



The nerves of the uterus are abundant and include both sympathetic 

 and spinal fibres, nonmedullated and medullated. Since their chief destina- 

 tion is the involuntary muscle and blood-vessels, the nonmedullated fibres 

 are associated with minute terminal ganglia from which the terminal filaments 

 pass to the myometrium. Other fibres reach the mucosa, within which a 

 close subepithelial plexus is formed, fibrils probably entering the epithelium. 



Changes During Menstruation and Pregnancy. Although liberation of a mature 

 ovum may occur at any time, in the vast majority of cases ovulation and menstruation 

 are synchronous processes, the uterine changes occurring regularly, every twenty- 

 eight days, only when the ovaries are functionally active. In anticipation of the 

 possible reception of a fertilized ovum, the uterine mucous membrane becomes 



