Bio 433: Mechanisms of Disease - Acute Inflammation

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Questions and Answers

Which of the following is NOT one of the main clinical signs of acute inflammation?

HYPERPLASIA (correct)

DOLOR

RUBOR

CALOR

What does an exudate imply about the vascular permeability?

Variable vascular permeability

Decreased vascular permeability

Increased vascular permeability (correct)

Normal vascular permeability

Which of the following best describes the role of neutrophil margination during acute inflammation?

Destruction of pathogens

Formation of new blood vessels

Direction movement towards the injury site (correct)

Secretion of histamine

What is the primary role of histamine in the immediate early response of acute inflammation?

To induce vasodilation Signup and view all the answers

What is the role of increased lymphatic drainage during inflammation?

To transport immune cells and antigens Signup and view all the answers

Which statement about the immediate sustained response is true?

It may lead to prolonged vascular changes Signup and view all the answers

How does the body initially combat injury during acute inflammation?

By increasing blood flow and vascular permeability Signup and view all the answers

Which mechanism is NOT involved in the function of acute inflammation?

Cytokine storm Signup and view all the answers

What is the role of endogenous pyrogens such as IL1 in the body during acute inflammation?

They are responsible for fever by acting on the hypothalamus. Signup and view all the answers

Which of the following is NOT a consequence of systemic effects during acute inflammation?

Localized tissue swelling and pain. Signup and view all the answers

Which protein is known for its bactericidal properties and is involved in the acute inflammatory response?

Lysozyme Signup and view all the answers

What may occur after the development of acute inflammation?

Potentially leads to complete resolution or chronic issues. Signup and view all the answers

What is the primary function of C-reactive protein (CRP) in the acute phase response?

To enhance phagocytosis and immune response. Signup and view all the answers

Which of the following mechanisms is primarily responsible for the resolution of acute inflammation?

Neutrophil apoptosis and clearance by macrophages. Signup and view all the answers

During acute inflammation, which type of white blood cells typically increases during bacterial infections?

Neutrophils Signup and view all the answers

In what situation is complete resolution of acute inflammation NOT possible?

When there is complete tissue necrosis. Signup and view all the answers

What initiates the margination process in neutrophils?

Histamine and thrombin activating P-selectin Signup and view all the answers

Which mediator is primarily responsible for the conversion of superoxide ions during microbial killing?

NADPH oxidase Signup and view all the answers

What is the main role of prostaglandins and leukotrienes in inflammation?

Facilitate vasodilation and inflammation Signup and view all the answers

What is a significant effect of oxygen-derived free radicals in the inflammatory process?

Endothelial damage and inactivation of antiproteases Signup and view all the answers

Which of the following substances is an example of a product from activation of platelets during inflammation?

5-hydroxy tryptamine Signup and view all the answers

What mechanism allows neutrophils to detect and respond to foreign substances during their movement?

Detection of concentration gradients through chemotaxis Signup and view all the answers

Which cytokines are specifically mentioned as activating E selectin on the endothelium?

IL-1 and TNF alpha Signup and view all the answers

How do neutrophils primarily kill microbes once they have internalized them?

Through the action of secondary lysosomes Signup and view all the answers

What is the primary causative organism of lobar pneumonia?

Streptococcus pneumoniae Signup and view all the answers

What happens to the alveoli in lobar pneumonia?

They should contain air. Signup and view all the answers

What typically characterizes a skin blister?

Includes a clear exudate if non-infected. Signup and view all the answers

Which mechanism signifies 'resolution by crisis' in lobar pneumonia?

The appearance of antibodies. Signup and view all the answers

In the context of inflammation in serous cavities, what condition may respiratory impairment lead to?

Pleural effusion. Signup and view all the answers

What type of necrosis is commonly associated with an abscess?

Liquefactive necrosis. Signup and view all the answers

Which of the following is a feature not typical of acute inflammation in serous cavities?

Presence of high neutrophil count. Signup and view all the answers

What is a common disorder of acute inflammation that results from inherited deficiencies?

Hereditary angio-oedema. Signup and view all the answers

Study Notes

Features of Acute Inflammation

Main clinical signs include: rubor (redness), tumor (swelling), calor (heat), dolor (pain), and functio laesa (loss of function).
Described through the ‘triple response’ consisting of brief blanching, followed by reddening, flare, and wheal.
Microscopic changes involve vascular dilation, increased red blood cell sludging, and fluid leakage into interstitium due to increased vascular permeability.

Definitions of Fluid Types in Inflammation

Transudate: Low protein content, indicating hydrostatic or oncotic pressure alterations.
Exudate: High protein content, suggesting an inflammatory process and increased vascular permeability.

Mechanisms of Inflammation

Vasodilation enhances blood delivery, raises temperature, and aids toxin removal.
Exudate carries immunoglobulins, dilutes toxins, and facilitates lymphatic drainage.
Increased lymphatic drainage aids in delivering pathogens to phagocytes and transporting antigens.

Chemical Mediators of Acute Inflammation

Three phases of response:
- Immediate early response: Histamine release from mast cells, basophils, and platelets causes vascular effects.
- Immediate sustained response: May occur due to direct endothelial cell damage.
- Delayed response: Peaks around 3 hours with numerous chemical mediators involved.

Key Chemical Mediators

Includes proteases, kinins (e.g., Bradykinin), cytokines (e.g., TNF alpha, IL-1), and arachidonic acid metabolites (e.g., prostaglandins, leukotrienes).
NSAIDs like aspirin block these mediators.
Platelets and neutrophils release additional inflammatory substances and mediators.

Neutrophil Role in Inflammation

Neutrophils marginate and emigrate towards the injury site by binding to the endothelium and moving through vessel walls.
Diapedesis involves relaxation of endothelial junctions and digestion of the vascular basement membrane.
They perform phagocytosis and microbial killing through oxygen-dependent and independent mechanisms.

Systemic Effects of Acute Inflammation

Fever and leukocytosis result from endogenous pyrogens (e.g., IL-1, TNF alpha).
Acute-phase response is characterized by decreased appetite, altered sleep patterns, and changes in plasma levels of acute-phase proteins (e.g., C-reactive protein).

Problems Caused by Acute Inflammation

Local complications include swelling, pain, and potential for autoimmunity.
Systemic issues may involve the spread of microbes or toxins, leading to shock.

Resolution of Acute Inflammation

Possible outcomes include complete resolution, progression to chronic inflammation, or fibrous repair.
Morphological changes reverse as neutrophils die, vessel permeability normalizes, and exudate drains.

Clinical Examples

Lobar Pneumonia: Caused by Streptococcus pneumoniae; affects young adults and alcoholics; characterized by worsening symptoms with resolution upon antibody appearance.
Skin Blister: Resulting in pain, exudate, and potential tissue damage, particularly if bacterial infection occurs.
Abscess: Solid tissues separate due to inflammatory exudate leading to liquefactive necrosis and pain.

Disorders of Acute Inflammation

Rare diseases, such as hereditary angioedema or alpha-1 antitrypsin deficiency, highlight the significance of complex inflammatory mechanisms.

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Description

Explore the mechanisms and features of acute inflammation in this quiz. Understand the clinical signs and microscopic changes associated with this pathological condition. Key topics include the triple response of inflammation and vascular dynamics.