BIOL 1003: Immunity Overview

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Questions and Answers

What is considered the first line of defense in innate immunity?

Antibody production

Inflammatory responses

Physical and biochemical barriers (correct)

B + T cell mediated responses

What is NOT one of the cardinal features of inflammation?

Heat

Swelling

Numbness (correct)

Redness

Which of the following is NOT a component of the innate immune system's physical barriers?

Mucus and cilia

Tight junctions

Skin

Antibodies (correct)

What is the primary role of inflammation in the immune response?

To repair vascular tissue damage Signup and view all the answers

What is the primary goal of the inflammatory response?

Limit extent of tissue damage Signup and view all the answers

Which statement best describes the vascular response during inflammation?

It involves increased vascular permeability. Signup and view all the answers

How does skin contribute to the innate immune system's chemical barriers?

By producing antimicrobial peptides Signup and view all the answers

What characterizes the tissue response in inflammation?

It is non-specific and uniform across all species. Signup and view all the answers

What factors can trigger an inflammatory response?

Temperature extremes Signup and view all the answers

What follows cellular injury in the acute inflammatory response?

Activation of plasma systems Signup and view all the answers

Which type of exudate indicates the presence of a bacterial infection?

Purulent exudate Signup and view all the answers

What is a common characteristic of chronic inflammation?

Granuloma formation Signup and view all the answers

Which of the following is NOT an acute phase reactant?

Leukocytes Signup and view all the answers

What is typically a cause of chronic inflammation?

High lipid content of microorganisms Signup and view all the answers

What changes in the blood count may indicate acute inflammation?

Increase in immature neutrophils Signup and view all the answers

What is the primary function of the complement system in the plasma protein systems?

To directly destroy pathogens and activate other immune components. Signup and view all the answers

Which primary kinin is responsible for causing pain and increasing vascular permeability?

Bradykinin Signup and view all the answers

Which type of cytokine is primarily produced by macrophages and lymphocytes in response to pathogens?

Interleukins Signup and view all the answers

What is the role of tumor necrosis factor-alpha (TNF-α) in inflammation?

Induces fever and increases inflammatory serum proteins. Signup and view all the answers

What is the function of leukotrienes synthesized by mast cells?

They produce long-lasting effects similar to histamine. Signup and view all the answers

What are the main receptors involved in recognizing pathogens by white blood cells?

Pattern recognition receptors (PRRs). Signup and view all the answers

Which process involves adherence, engulfment, phagosome formation, and destruction of a target?

Phagocytosis. Signup and view all the answers

What is the primary mechanism by which mast cells release their mediators during inflammation?

Degranulation. Signup and view all the answers

How do interleukins assist in the immune response during inflammation?

By regulating adhesion, attraction, and activation of immune cells. Signup and view all the answers

What is the primary effect of histamine released from mast cells?

Enhances blood flow and increases vascular permeability. Signup and view all the answers

What does the term exudate refer to in the context of inflammation?

The fluid that leaks from blood vessels into surrounding tissues. Signup and view all the answers

Which phase of inflammation is characterized by the migration of leukocytes to the site of injury?

Exudative phase. Signup and view all the answers

Which of the following statements about the kinin system is true?

It causes vasodilation and leukocyte migration. Signup and view all the answers

Study Notes

Innate and Adaptive Immunity

Innate Immunity: The body's first line of defense, consisting of physical and biochemical barriers.
Adaptive Immunity: Acquired immunity involving B and T cells, providing 'memory' responses as a third line of defense.

Physical and Chemical Barriers

Physical Barriers:
- Skin covers approximately 2 m².
- Epithelial linings of gastrointestinal, genitourinary, and respiratory tracts span around 32 m².
- Includes tight junctions, sloughing off of cells, mucus, and cilia.
Chemical Barriers:
- Secretion of saliva, tears, earwax, sweat, and mucus contributes to protection.
- Antimicrobial peptides, including cathelicidins and collectins, play a role.
- pH levels: Skin (3-5), Stomach (1.5-3.5).

Inflammation: Response Mechanism

Inflammation is the host response to vascular tissue damage, featuring redness, heat, swelling, pain, and loss of function.
Goals include limiting tissue damage, destroying microorganisms, initiating adaptive immune responses, and clearing debris.
Acute Inflammatory Response: Involves cellular injury, activation of plasma systems, and release of autocoids.

Plasma Protein Systems

Systems contain inactive enzymes (proenzymes) that sequentially activate to combat infections.
The Complement System activates both innate and adaptive immunity, destroying pathogens and enhancing the inflammatory response through pathways like classical, lectin, and alternative.
Coagulation System creates a fibrin meshwork to trap pathogens and aid in repair.
The Kinin System activates inflammatory cells and elevates vascular permeability.

Cellular Mediators of Inflammation

White Blood Cells (WBC): Includes granulocytes, platelets, monocytes (macrophages, dendritic), and lymphocytes (T, B, NK).
Mast Cells: Located close to blood vessels; release histamine and chemotactic factors upon degranulation.
Cytokines are critical in signaling and modulating immune responses, classified into interleukins, interferons, and tumor necrosis factor-alpha (TNF-α).

Cytokines

Interleukins (IL): Produced primarily by macrophages and lymphocytes, facilitating chemotaxis and regulating immune activity.
Interferons (IFN): Protect against viral infections; types include IFN-alpha, IFN-beta, and IFN-gamma.
Tumor Necrosis Factor-alpha (TNF-α): Induces fever, increases inflammatory proteins, and can cause muscle wasting.
Chemokines: Attract leukocytes to inflammation sites.

Phagocytosis

A cellular process that engulfs and disposes of foreign material, carried out in two phases:
- Extravasation: Involves margination and diapedesis.
- Phagocytosis: Involves adherence, engulfment, phagosome formation, and fusion with lysosomes.

Acute vs. Chronic Inflammation

Acute Inflammation: Self-limiting and characterized by heat, swelling, redness, and pain. Leads to exudative fluid production.
Chronic Inflammation: Lasting over two weeks, often resulting from an unsuccessful acute response, high lipid content microbes, or toxins.

Exudative Fluids

Serous Exudate: Watery fluid indicating early inflammation.
Fibrinous Exudate: Thick, clotted fluid reflecting advanced inflammation.
Hemorrhagic Exudate: Contains blood, indicating bleeding.
Purulent Exudate: Pus indicating bacterial infections.

Systemic Acute Inflammation

Fever: Triggered by pyrogens acting on the hypothalamus.
Leukocytosis: Increased WBC count, with a 'left shift' indicating more immature neutrophils.
Acute Phase Reactants: Elevated plasma proteins such as C-reactive protein and fibrinogen, associated with the inflammatory response.

Chronic Inflammation Characteristics

Dense lymphocyte and macrophage infiltration, granuloma formation, epithelioid and giant cell formation.

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Description

This quiz covers the fundamentals of innate and adaptive immunity, including their mechanisms and roles in the immune response. It delves into the first, second, and third lines of defense, as well as defects in these systems. Enhance your understanding of how the body protects itself against diseases.