Immune System: Second Line of Defense Flashcards

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Questions and Answers

What is the second line of defense in the immune system?

Adaptive immunity

General, non-specific response to infection (correct)

Physical barriers

None of the above

What are the components of the second line of defense?

Recognition, Fever, Inflammation, Complement protein, Phagocytosis, Interferon

What do phagocytic cells do?

Engulf and enclose microbes in vacuoles

What are macrophages known for?

Large phagocytic cells that destroy extracellular antigens Signup and view all the answers

What triggers inflammation?

Damaged tissues and basophils releasing chemicals Signup and view all the answers

What role does a fever play in fighting infections?

Helps immune cells perform more efficiently and hinders bacterial growth Signup and view all the answers

What are the two main roles of complement proteins?

Mark pathogens for destruction and create holes in foreign cells Signup and view all the answers

How do phagocytes reach an area of injury or infection?

They migrate through blood vessel spaces into tissue spaces via diapedesis and respond to chemical stimuli. Signup and view all the answers

What is a systemic reaction to infections, allergies, and other illnesses?

Fever Signup and view all the answers

What initiates a fever?

Pyrogens reset the hypothalamus to a higher temperature setting Signup and view all the answers

What are some benefits of fever?

Inhibiting microorganism multiplication, reducing available iron, increasing metabolism Signup and view all the answers

What is the main role of phagocytes?

Survey, ingest, eliminate, and extract immunological information from foreign matter Signup and view all the answers

The five steps in phagocytosis are: chemotaxis, adherence, ingestion, digestion, and ______.

killing Signup and view all the answers

What are cytokines?

Molecules secreted during phagocytosis that trigger the third line of defense Signup and view all the answers

What are interferons?

Produced by certain white blood cells and tissue cells Signup and view all the answers

What does the complement protein cascade reaction consist of?

Initiation, Amplification, Cascade, Polymerization, Membrane attack Signup and view all the answers

What are the pathways for complement proteins?

Classical pathway, MB-Lectin pathway, Alternative pathway Signup and view all the answers

Study Notes

Second Line of Defense in the Immune System

The second line of defense represents the body's innate immunity, providing a non-specific response to infections.
Key components include recognition, fever, inflammation, complement proteins, phagocytosis, and interferons.

Phagocytic Cells

Phagocytic cells engulf and enclose microbes within vacuoles to neutralize threats.
Macrophages are a significant type of phagocytic cell, effective at destroying extracellular antigens.

Inflammation

Triggered by damaged tissues and basophils releasing chemicals that attract immune cells such as macrophages.
Characteristics of inflammation include redness, swelling, warmth, pain, and potential loss of function.

Role of Fever

Fever raises body temperature, enhancing the efficiency of immune cells and inhibiting bacterial growth.
It serves as a systemic response to infections, allergies, and cancers, with initiation by pyrogens that reset the hypothalamic thermostat.

Function of Complement Proteins

Circulate in blood plasma, assisting in immune response by marking microbes for destruction and forming pores in foreign cells.
The complement protein cascade includes initiation, amplification, cascade, polymerization, and membrane attack stages.

Surveillance Mechanism

White blood cells (WBCs) continually monitor for foreign agents and infections, acting as a surveillance system.
Phagocytes perform vital roles of surveying, ingesting, and eliminating pathogens, while also extracting immunological information.

Phagocytosis Process

Involves five steps: chemotaxis (movement toward infection), adherence, ingestion, digestion, and killing of pathogens.
Cytokines released during phagocytosis trigger the activation of the body's third line of defense.

Benefits of Fever

Inhibits growth of temperature-sensitive microorganisms and reduces available iron, a vital nutrient for bacteria.
Increases metabolism and promotes protective processes within the body.

Complement Protein Pathways

Include classical pathway (most commonly used), MB-Lectin pathway, and alternative pathway, enhancing the effectiveness of antibodies and phagocytic cells in clearing microbes.

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Description

Test your knowledge of the innate immune system with these flashcards focusing on the second line of defense. Explore key concepts such as recognition, fever, inflammation, and the role of complement proteins and phagocytosis. Perfect for students of biology or anyone interested in understanding how our bodies fight infections.