CHAPTER XII 

 WOUNDS AND WOUND INFECTIONS 



THE SYMPTOMS, TREATMENT, AND HEALING OF WOUNDS 



A wound is any break in the continuity of the skin or mucous 

 membrane. More or less destruction of tissue always occurs as 

 the result of a wound. 



The following kinds of wounds are recognized: (1) Incised 

 wounds, with clean-cut margins; (2) lacerated wounds, with flap- 

 like tears; (3) punctured wounds, with small, round openings; (4) 

 contused wounds, with the tissues bruised from contact with a 

 blunt instrument. The size of a wound is no guide to the prog- 

 nosis, which should depend in large measure on the situation oi 

 the wound and the nature of the injured vessels. Minor wounds 

 are just as likely to lead to complications as are extensive ones. 



The symptoms of wounds are hemorrhage, pain, gaping, and 

 disturbed function. 



Hemorrhage is the escape of blood from the tissues' in which it 

 is normally contained. It varies according to the size and kind 

 of the wounded blood-vessel, but is most pronounced in incised 

 wounds. When an artery is injured the blood is bright red in color 

 and spurts out with each heart-beat. An injured vein allows blood 

 of dark-red color to escape — it flows steadily from the wound and 

 upon exposure to the air turns lighter red. Capillary hemorrhage 

 is intermediate in color and oozes. If hemorrhage is into the body 

 cavities, the blood is rapidly and entirely absorbed. From the 

 tissues absorption is slower, and a "black-and-blue spot" or "blood 

 blister" (hematoma) remains for some time to- mark the location. 

 Where over one-third of the total volume of blood is lost, the 

 pressure fafls and death may foUow. After excessive loss of blood 

 the visible mucous membranes become very pale, the animal gets 

 dizzy, loses consciousness, and goes into convulsions. There is a 

 rapid re-establishment in the quantity of the blood following 

 hemorrhage by absorption of fluids from the tissues and intestines. 

 The solid constituents regain their normal numbers more slowly, 



165 



