Lymphatic and Immune Systems Vocabulary

Vocabulary flashcards detailing key concepts, antibody types, immune responses, and cellular mechanisms from Chapter 17 Lymphatic & Immune Systems notes.

Systemic Chronic Inflammation

A slow, long-term inflammation affecting the entire body that lasts from months to years, contributing to over $50\%$ of all deaths from diseases such as diabetes mellitus, heart disease, and stroke.

Pyrexia

An abnormal elevation of body temperature, commonly referred to as fever.

Febrile

A medical term used to describe a person who has a fever.

Pyrogen

A fever-producing substance secreted by neutrophils and macrophages during phagocytosis that stimulates the anterior hypothalamus to secrete prostaglandin E (PGE).

Prostaglandin E (PGE)

A substance secreted by the anterior hypothalamus in response to pyrogens that resets the body's temperature set point above normal.

Antibodies

Gamma globulin proteins (also called immunoglobulins, Ig) formed by B cells that are found in plasma and body secretions and bind specifically to the antigen that prompted their production.

IgA

A class of antibody that populates mucous membranes in the intestines, respiratory tract, and urinary tract, and is also present in saliva, tears, and breast milk.

IgD

A class of antibody existing in the blood in very small amounts that may activate basophils and mast cells.

IgE

A class of antibody involved primarily in allergic reactions.

IgG

The most abundant immunoglobulin, constituting $80\%$ of all circulating antibodies; it serves as the primary antibody of the secondary immune response and is the only antibody that can cross the placenta.

IgM

A class of antibody active in the primary immune response and involved in the agglutination of incompatible blood types.

Monoclonal Antibodies (mAbs)

Laboratory-engineered antibodies created to bind to a specific target in the body, such as cancer cell surface antigens or viral spike proteins.

Cellular Immunity

A branch of adaptive immunity (cell-mediated immunity) that uses T cells (cytotoxic, helper, and memory T cells) to directly destroy pathogens located within host cells.

Cytotoxic T Cells

T cells (also called killer T cells) in cellular immunity that carry out the direct attack and destruction of foreign or infected cells.

Helper T Cells

T cells that support the immune attack by secreting interleukins to attract neutrophils, natural killer cells, and macrophages, while also stimulating T and B cell production.

Memory T Cells

Long-lived T cells that retain a memory of a specific pathogen following an initial attack to allow for a rapid immune response upon re-exposure.

Antigen-Presenting Cell (APC)

A phagocyte (such as a macrophage, reticular cell, or B cell) that ingests a pathogen and displays fragments of the antigen on its surface to activate T cells.

Humoral Immunity

A branch of adaptive immunity (antibody-mediated immunity) that focuses on pathogens outside the cell and uses antibodies produced by plasma cells to mark antigens for destruction.

Plasma Cells

Effector B cells that secrete large numbers of antibody molecules (up to $2000$ molecules per second) into the blood stream.

Primary Response

The initial reaction of the immune system when first exposed to a new antigen, requiring $3\text{ to }6\text{ days}$ for blood antibody levels to rise.

Secondary Response

A rapid immune reaction occurring when memory B cells encounter a previously seen antigen, producing large quantities of antibodies within hours instead of days.

Antibody Titer

A blood test used to detect the presence and determine the quantitative amount of specific antibodies in the blood.