[2] By trauma is understood a wound or injury of any sort.




CHAPTER IV

THE REACTIONS OF THE TISSUES OF THE BODY TO INJURIES.--INFLAMMATION.--
THE CHANGES IN THE BLOOD IN THIS.--THE EMIGRATION OF THE CORPUSCLES OF
THE BLOOD.--THE EVIDENT CHANGES IN THE INJURED PART AND THE MANNER IN
WHICH THESE ARE PRODUCED.--HEAT, REDNESS, SWELLING AND PAIN.--THE
PRODUCTION OF BLISTERS BY SUNBURN.--THE CHANGES IN THE CELLS OF AN
INJURED PART.--THE CELLS WHICH MIGRATE FROM THE BLOOD-VESSELS ACT AS
PHAGOCYTES.--THE MACROPHAGES.--THE MICROPHAGES.--CHEMOTROPISM.--THE
HEALING OF INFLAMMATION.--THE REMOVAL OF THE CAUSE.--CELL REPAIR AND
NEW FORMATION.--NEW FORMATION OF BLOOD-VESSELS.--ACUTE AND CHRONIC
INFLAMMATION.--THE APPARENTLY PURPOSEFUL CHARACTER OF THE CHANGES IN
INFLAMMATION.


Injury and repair have already been briefly considered in their
relation to the normal body and to old age; there are, however,
certain phenomena included under the term inflammation which follow
the more extensive injuries and demand a closer consideration than was
given in Chapter II. These phenomena differ in degree and character;
they are affected by the nature of the injurious agent and the
intensity of its action, by the character of the tissue which is
affected and by variations in individual resistance to injury. A blow
which would have no effect upon the general surface of the body may
produce serious results if it fall upon the eye, and less serious