chapter14

What are the two main types of immunity?

Innate (non-specific) Immunity and Adaptive (specific) Immunity.

Characteristics of Innate Immunity:

Immediate, non-specific, no memory. Includes barriers (skin, mucous membranes), inflammation, fever, and phagocytes.

Characteristics of Adaptive Immunity:

Specific to pathogens, slower response, has memory. Involves lymphocytes (B cells and T cells) and antibodies.

What are the 3 major functions of the Complement System (O.I.L)?

Opsonization, Inflammatory Response, and Lysis.

Describe Opsonization:

Tags microbes for phagocytosis.

Describe the Inflammatory Response (Complement System):

Recruits immune cells to infection sites.

Describe Lysis (Complement System):

Forms the membrane attack complex (MAC) to burst bacterial cells.

What triggers fever?

Triggered by pyrogens (often from infections).

What are the benefits of fever?

Inhibits pathogen growth, speeds up immune reactions, and increases metabolism.

Interferon (IFN)

Antiviral proteins that block viral replication in neighboring cells.

Endotoxin

Lipopolysaccharide (LPS) from Gram-negative bacteria; triggers fever and shock.

Plasma Cell

Activated B cell that produces antibodies.

Cytokines

Chemical messengers coordinating immune response.

Diapedesis

Movement of WBCs through vessel walls to infection site.

T-helper (CD4+) Cells

Activate B cells, macrophages, and cytotoxic T cells.

Phagocytes

Engulf and digest pathogens (macrophages, neutrophils).

Monocytes

Circulating phagocytic precursors that mature into macrophages.

Immunoglobulins

Antibodies; produced by B cells for pathogen recognition.

Where do Lymphocytes develop and mature?

From **bone marrow

• B cells** (mature in bone marrow)
• T cells (mature in thymus).

What are Granulocytes and what role do they play?

Neutrophils, eosinophils, basophiles—part of innate defense.

What are the Primary lymphoid organs?

Bone marrow, thymus.

What are the Secondary lymphoid organs and their function?

Lymph nodes, spleen, tonsils—where immune responses activate.