inflammation 1 l General pathology MCQs for dental students

inflammation 1 l General pathology MCQs for dental students (multiple choice question)

 Acute Inflammatory Process

• Any time the body is injured by exogenous or endogenous elements, it must respond. The inflammatory process is the mechanism for dealing with injuries caused by these elements. Most of the time the inflammatory process is beneficial, but occasionally, the inflammatory process is ultimately the cause of severe damage and must be held under control. Many immune system diseases are the result of excessive or unnecessary inflammatory processes. There are two broad categories of inflammatory processes, acute and chronic.

• Acute inflammation is most often limited in area and duration and is characterized by the cardinal signs of inflammation . Occasionally, acute inflammation is extensive and involves multiple organs or systems. Chronic inflammation, one possible result of acute inflammation, is characterized by a long duration or a history of repeated insults or injuries. Other outcomes of acute inflammation are abscess formation, resolution of inflammation (reversal of the inflammatory process with return to normal), and healing or repair of the area. Although the repair process is discussed at the end of this chapter, repair begins at almost the same time he inflammatory process is activated. That is, they occur simultaneously.

Phases of the Acute Inflammatory Process

• There are three phases of the acute inflammatory process. The first phase, or initiation, is activated when the injury occurs. It comprises changes to the structure of small blood vessels (microcirculation) in the area of the injury, leading to loss of fluid from the blood and movement of white blood cells from the blood vessels to the injured area. The second phase (amplify cation) involves the action of chemical substances that direct more and different types of white blood cells into the injured area.

• The white blood cells act to increase the response, quickly neutralize whatever caused the injury, and clean up the debris resulting from the injury. The third phase (termination) requires other chemical substances to stop or inhibit the inflammatory process; if the inflammatory process continues unhindered, more damage than the initial injury will result.

• Understanding the inflammatory process requires an understanding of events occurring within the tissues on a microscopic level and the stimuli causing these events.

Initiation Phase

• The first reaction during initiation is an immediate constriction of the microcirculation comprising the arterioles, capillaries, and venules known as vasoconstriction (Event 1).

• The constriction is very brief, lasting several minutes or less, but it serves the purpose of controlling bleeding, especially in small injuries. When tissue cells are damaged, as the cells of the foot in this situation, they release substances called chemical mediators that start the inflammatory process. Their first action is to cause the blood vessels in the area to undergo vasodilation (Event 2), or increase in diameter, so more blood (hyperemia) and nutrients can be brought into the area.

• Some chemical mediators cause blood vessels to become more permeable (Event 3) as cells in the capillaries separate slightly, forming microscopic gaps between them. This allows plasma fluid and white blood cells in the vessels to travel out of the vessels and into the injured area. The plasma fluid and  white blood cells clear the area of dead or injured cells and any foreign material that entered along with the nail.