152 EQUINE ANATOMY. 



with a flattened epithelium. Is covered with an abundance of 

 mucus, and has longitudinal folds (ruga). 



Outer or Muscular. Of circular and longitudinal unstriped 

 fibres. 



Serous or Peritoneal. Only in its anterior part. 



Vessels. 



Internal pudic. 



Nerves. 



Pelvic plexus. 



THE UTERUS. 



The uterus is a hollow, muscular organ, in which the ovum is 

 received, and the foetus developed. It is situated in the abdominal 

 cavity in the sub-lumbar region, its posterior extremity ending 

 in the pelvic cavity. 



Relations. 



Above, to rectum; below, with bladder; anteriorly and laterally 

 with intestinal convolutions; behind, with vagina. 



Parts. 



Behind is a constriction, the cervix (or neck), with a circular 

 opening, the os. In front is the fundus, directly continuous with 

 the two cornua. These have a superior or convex, and posterior 

 or concave curvature, a base continuous with the uterus, and a 

 summit continuous with the oviducts. 



Ligaments. 



Two broad, descending from the sub-lumbar region to the sides of 

 the uterus and cornua and enveloping the ovaries and their ducts. 



Two rudimentary, round ligaments, running from the sides of 

 the uterus to the beginning of the inguinal canal. 



Structure. 



Serous coat, complete, from peritoneum. 



Muscular coat, longitudinal (external) and circular (deep) 

 unstriped fibres. The latter most marked about the cervix. 



Some muscular fibres pass into the broad ligaments. 



Mucous coat, of basement membrane covered with ciliated 

 epithelium, except at the cervical canal, where it is columnar, 

 and at the os, where it is flattened. It is thrown into folds at the 

 cervix and is divided into two canals those of the cervix and 

 body. It is supplied with mucus by numerous simple and cylin- 

 drical glands. 



