OIA1010 INFLAMMATION

What is inflammation?

A tissue response to injury or infection, aiming to bring leukocytes and plasma proteins to the affected site to eliminate the cause and start healing

Is inflammation always beneficial?

Generally, yes, but severe or misdirected inflammation can cause tissue damage.

What are the two types of inflammation based on duration?

Acute and chronic inflammation.

What are the cardinal signs of inflammation?

Redness (rubor), heat (calor), swelling (tumor), pain (dolor), and loss of function (functio laesa).

Name three common causes of inflammation.

Infective agents (bacteria, viruses), physical agents (trauma, heat), and immune reactions (autoimmune disorders).

How does tissue necrosis lead to inflammation?

Dead cells release signals that trigger an inflammatory response.

What are the two main components of the inflammatory response?

Vascular changes and cellular events.

What triggers the vascular changes in inflammation?

Chemical mediators like histamine causing vasodilation and increased permeability.

What is chemotaxis?

The directed movement of leukocytes toward the site of infection along a concentration gradient of chemoattractants.

What are the effects of vasodilation in inflammation?

Increased blood flow leading to redness and heat.

How does increased vascular permeability contribute to inflammation?

It allows fluid and proteins to escape into tissues, causing edema (swelling).

What are the two mechanisms that increase vascular permeability?

Retraction of endothelial cells and direct endothelial injury.

What is the role of neutrophils in inflammation?

They are rapidly recruited to the site, perform phagocytosis, and release enzymes to destroy pathogens.

What are macrophages' roles in inflammation?

They arrive later to clean up debris, ingest microbes, and produce growth factors for tissue repair.

What are the stages of leukocyte emigration?

Loose attachment and rolling, firm adhesion, migration across the endothelium, and chemotaxis.

How do selectins and integrins function in leukocyte migration?

Selectins mediate rolling, while integrins mediate firm adhesion to endothelial cells.

What are the three phases of phagocytosis?

Recognition and attachment, engulfment, and killing/degradation.

What molecules act as opsonins in phagocytosis?

IgG, complement proteins (C3b), and some lectins.

What mechanisms do phagocytes use to kill microbes?

Reactive oxygen species (ROS), nitric oxide, and lysosomal enzymes.

Name two chemical mediators involved in the vascular response.

Histamine and prostaglandins.

What are the key cytokines in inflammation?

TNF, IL-1, and IL-6.

What role does complement play in inflammation?

It enhances phagocytosis (opsonization), promotes chemotaxis, and forms the membrane attack complex (MAC).

What is resolution in inflammation?

The ideal outcome where the harmful agent is removed, and tissue returns to normal.

When is chronic inflammation likely to occur?

When the causative agent cannot be removed, as seen in autoimmune diseases.

What factors favor resolution of acute inflammation?

Minimal cell death, rapid elimination of the causative agent, and efficient removal of exudate.

How does histamine contribute to the vascular response?

By causing vasodilation and increasing vascular permeability.

What is the significance of ICAM-1 and VCAM-1 in inflammation?

These endothelial adhesion molecules bind integrins on leukocytes to mediate firm adhesion.

Why are neutrophils short-lived in inflammation?

They degranulate and release enzymes that may also cause tissue injury before dying.

How do macrophages contribute to tissue repair?

By producing growth factors and removing debris.

What is the role of fibrinolysin in resolution?

It dissolves fibrin clots, aiding in the restoration of normal tissue.