THE FIVE ALARM FIRE
What is inflammation?
A protective immune-driven process intended to eliminate the cause of cell injury and remove necrotic cells/tissues
The major effect of the vascular phase of inflammation is ________.
Vasodilation
The primary phagocyte that arrives early at an inflammatory site is the ________.
Neutrophils
What is chemotaxis?
The directed movement of leukocytes toward the site of infection/injury along a gradient of chemoattractants
What is an abscess?
A localized area of inflammation containing purulent exudate
The five cardinal signs of inflammation are heat, redness, swelling, pain, and ________.
Which type of exudate is described as a watery fluid with a low protein level?
A. Purulent
B. Fibrinous
C. Serous
D. Hemorrhagic
C. Serous
Example: Fluid in a blister
Which cell is considered a hallmark of acute inflammation?
A. Macrophage
B. Neutrophil
C. Monocyte
D. Platelet
Neutrophil
The movement of leukocytes through the vessel wall is called ________.
Transmigration
Which finding would be most consistent with an acute inflammatory response?
A. Decreased WBC count
B. Increased neutrophils
C. Decreased CRP
D. Increased RBC count
B. Increased neutrophils
Which vascular change is primarily responsible for redness at an inflammatory site?
A. Vasoconstriction
B. Vasodilation
C. Decreased vascular permeability
D. Coagulation
B. Vasodilation
Compare purulent exudate with hemorrhagic exudate.
Purulent: Contains pus composed of degraded WBCs, proteins and tissue debris.
Hemorrhagic: Contains RBCs and occurs with severe tissue injury involving damaged blood vessels.
What is the relationship between a monocyte and a macrophage?
A monocyte circulates in the blood. After it migrates into the tissues, it becomes a macrophage.
Monocyte in blood → macrophage in tissue
During which process do leukocytes move toward the inner lining of a blood vessel and begin "rolling" along the endothelium?
A. Phagocytosis
B. Chemotaxis
C. Margination
D. Transmigration
C. Margination
Give TWO differences between acute and chronic inflammation.
Acute inflammation:
Chronic inflammation:
Explain why increased vascular permeability causes swelling.
Increased vascular permeability allows fluid to leave the blood vessels and enter the interstitial spaces, producing swelling.
An exudate containing large amounts of fibrinogen that forms a thick, sticky meshwork is called ________ exudate.
Fibrinous exudate
Give THREE roles of macrophages in inflammation.
Put the four major steps of the cellular phase of acute inflammation in order:
Chemotaxis → Activation & phagocytosis → Margination & adhesion → Transmigration
Margination & adhesion → Transmigration → Chemotaxis → Activation & phagocytosis
A patient has the following lab results 24 hours after an inflammatory event:
WBC = 24 × 10⁹/L
Segmented neutrophils = 15,000/µL
CRP = 7.5%
What do these results suggest?
An inflammatory response.
A patient injures their ankle. Within a short period of time, the area becomes red, warm, swollen and painful. Explain the vascular changes responsible for:
A. Redness/warmth
B. Swelling
C. Pain
A. Vasodilation → ↑ blood flow → redness and warmth
B. ↑ vascular permeability → fluid enters interstitial spaces → swelling
C. Fluid entering the interstitial space contributes to pressure on surrounding nerves → pain
Exudate formation → Tissue injury → Flow stasis/coagulation → Vasodilation → Vasoconstriction → Altered vessel permeability
Tissue injury → brief vasoconstriction → vasodilation → altered vessel permeability → exudate formation → flow stasis & coagulation
Patient A has a new acute bacterial infection.
Patient B has had persistent inflammation for several months.
Which inflammatory cell would you expect to predominate in each patient?
Patient A → Neutrophils
Patient B → Macrophages/mononuclear cells
Neutrophils arrive early and are a hallmark of acute inflammation, whereas macrophages have an important role in chronic inflammation
A neutrophil has adhered to the endothelium, moved through the vessel wall, and is now in the surrounding tissue.
A. What process guides it toward the site of infection?
B. Name TWO examples of substances that can guide it.
C. Once it reaches the pathogen, what are the THREE steps of phagocytosis?
A. Chemotaxis
A patient has a persistent inflammatory response surrounding material that the body cannot easily digest or eliminate. Modified macrophages accumulate, become epithelioid cells, and clump together to form multinucleated giant cells. Connective tissue eventually encapsulates the area.
A. What type of inflammation is occurring?
B. What structure is being formed?
C. Give TWO examples of things from the lecture that can cause this response.
A. Granulomatous inflammation
B. A granuloma
C. Any two:
A granuloma is typically a small 1–2 mm lesion of modified macrophages surrounded by lymphocytes.