CIRCULAR DISTURUANCKS. 115 



Hematuria is hemorrhage into the urinar}' tract or bloody 

 urine. The blood ma_y escape from the kidney, and if so there 

 will be tubular casts discernible on microscopic examination of 

 the urine ; it may come from the ureter or bladder, and would 

 then be thoroughly mixed with the urine ; or it may have its 

 origin from the urethra and would not be mixed with the urine 

 but would usually precede it. 



Hcmatidrosis is hemorrhage) from the surface of the skin 

 and is the so-called sweating of the blood and is caused l)v in- 

 creased permeability of cutaneous capillaries. 



Entcrorrhayia is hemorrhage from the intestinal mucosa and 

 may be differentiated from hematemesis by the appearance of 

 the extravasate in tlie feces. The extravasate in hematemesis lias 

 the appearance of coft'ee bean grains in the feces while the en- 

 terorrhagia extra\asate retains tlie hemoglobin colcir and is not 

 broken up into granules. (The coffee bean appearance of l)lood 

 extravasated into the stomach is due to the action of the hydro- 

 chloric acid of the gastric juice.) Enterorrhagia is caused by 

 infection as in anthrax and by caustics. 



Hcuiatomctra is lieniorrhage from the uterine mucosa the 

 extrayasate being almost entirely retained in the uterus. This 

 is usually caused by improper removal of retained placenta. 



Mctrorrlnu/io is hemorrhage from the uterine mucosa and the 

 extra\-asate passes out of the uterus. Menstruation in the hu- 

 man is an illustration of metrorrhagia. 



Hciiiococlia is hemorrhage into the jwritoneal cavity and is 

 caused by rupture of the peritoneum or some alidominal organ. 



Hemothorax is hemorrhage in the pleural cavity, and is 

 caused l)y ruptured pleura as a result of fracture of a rib, etc. 



Hematocele is lieinorrhagc into the tunica xtiginalis ca-rity. 

 This may l)e the result of laceration or rupture of the tunica 

 vaginalis testis. 



Effects. — The effects of a hemorrhage depend upon the 

 quantity of blood lost and the location and secondary changes 

 of the extravasate. In health the vascular system practically 

 maintains a constant blood pressure by accomodating the 

 capacity of the blood channels to the volume of the blood. 



The' ciuantity of blood that an animal may loose without be- 

 ing seriously affected varies according to its age and healtli. 



The blood tissue of the horse has been estimated at from 

 1-lfi to 1-13 of the total body weight. One-tenth of the esti- 

 mated total amount of blood in the body has been withdrawn 

 from horses used in the production of anti-toxin once every t'.vo 

 weeks for from six to eight months without injurious results. 



