Immune System: Innate and Adaptive Defense Mechanisms

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

Physical barriers, chemical barriers, and normal biota.

What are the components of the second line of defense?

Phagocytosis, inflammation, fever, and antimicrobial products.

What characterizes the third line of defense in the immune system?

Cells learn and develop over time to target specific pathogens.

What role does the skin play in the immune system?

It serves as a physical barrier to block invasion at the portal of entry.

What is the function of lysozyme in the immune system?

It is a nonspecific chemical defense that breaks down bacterial cell walls.

What is the significance of pH in the immune system?

Different pH levels in various body fluids inhibit the growth of certain bacteria.

What are PAMPs?

Pathogen-associated molecular patterns recognized by phagocytes.

What is the role of macrophages in the immune system?

They patrol, identify, and destroy foreign cells and pathogens.

What are the primary lymphatic organs?

Red bone marrow and thymus.

What is the function of the spleen in the immune system?

It filters pathogens from the blood and removes old blood cells.

What are the signs of inflammation?

Rubor (redness), calor (warmth), tumor (swelling), and dolor (pain).

What triggers the inflammatory response?

Trauma, tissue injury, and specific immune reactions.

What is the purpose of fever in the immune response?

To increase body temperature to enhance immune function and inhibit pathogen growth.

What are pyrogens?

Substances that reset the body's temperature to a higher setting.

What is the role of interferons in the immune system?

They are proteins produced in response to viral infections that help inhibit virus replication.

What is the classical pathway in the complement system?

A cascade reaction that leads to opsonization, inflammation, and cytolysis of pathogens.

What are antimicrobial peptides?

Short proteins that insert into microbial membranes to kill microbes.

What is the function of transferrin in the immune system?

It exports iron, which is essential for bacterial growth.

What are defensins?

Cationic proteins that create channels in bacterial membranes, leading to cell lysis.

What is the role of neutrophils in the immune response?

They are phagocytes that react early in the inflammatory response and are a primary component of pus.

What is the significance of the thymus in immune function?

It is where T cells mature and gain the ability to recognize specific antigens.

What is the role of cytokines in inflammation?

They are signaling molecules that attract immune cells to damaged areas.

What are the effects of high fever?

It can lead to tachycardia, tachypnea, and a lowered seizure threshold.

What is the function of lactoferrin?

It binds iron and has antimicrobial properties, crossing the blood-brain barrier.

What is the role of Peyer's patches?

They are lymphoid nodules in the ileum that monitor intestinal bacteria and prevent growth of pathogenic bacteria.

What is the function of sebaceous secretions?

They produce sebum, which has antimicrobial properties.

What is the role of normal biota in the immune system?

They provide a genetic component of susceptibility and help prevent pathogen colonization.