DICTIONARY OF THE VETERINARY ART. 281 



Ureters. Two small tubes by which the urine is conveyed 

 from the kidneys to the bladder. 



Urethra. A membranous and muscular tube by which the 

 urine is conveyed from the bladder j it is of considerable 

 length in the horse. 



Urine, Excessive Discharge of. (See Diabetes.) 

 Urine, Incontinence of. (See Incontinence.) 

 Uterus. The womb. The uterus of the mare is very 

 unlike that of the human subject, in whom it consists of one 

 bag, rather of an oval shape, somewhat resembling a pear ; 

 but in the mare and other quadrupeds, it has a body and two 

 branches, called its horns. The uterus terminates in the va- 

 gina by a narrow portion, called the neck, or mouth of the 

 womb. The extremities of these horns have tubes attached 

 to them, which, from the name of the discoverer, are called 

 Fallopian tubes ; one end of each is expanded, and has a 

 fringed kind of edge : this is named the fimbria of the Fallo- 

 pian tube. The Fallopian tube is very tortuous in its form ; 

 and that end which proceeds from the horn of the uterus is 

 extremely small ; but the other, which is slightly attached to 

 the ovarium, is considerably larger. The ovarium is an ob- 

 long body, about the size of a small hen's egg. The ovaria 

 — for there are two of them — are composed of a number of 

 transparent vesiculae, called ova, (eggs;) each ovum is sur- 

 rounded with cellular membrane ; and when the ovum is im- 

 pregnated and passes into the uterus, it leaves a mark which 

 is named corpus luteum. 



Uvula. In the human subject, the small flesh -like sub- 

 stance hanging in the middle and back part of the throat is 

 thus named. In the horse this is of a very different form. 

 The uvula completely closes the opening to the pharynx, 

 though it readily yields to the passage of food, or any liquid, 

 towards the gullet ; it prevents, also, there turn of any thing 

 to the mouth, even the air which is expired from the lungs, 

 unless it be thrown aside by a violent effort, as in coughing. 

 It is on this account that, when the horse is affected with 

 nausea, or has the action of the stomach inverted, — which 

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