Immunity and Stress Lecture Notes

Vocabulary flashcards generated from lecture notes covering innate and adaptive immunity, hypersensitivity types, transplant rejections, autoimmune disorders, HIV/AIDS categories, and physiological stress responses.

Innate Immunity

A nonspecific, immediate immune defense mechanism that recognizes nonself using barriers such as skin, mucous membranes, chemicals, and the microbiome without requiring prior exposure.

Acute Phase Inflammatory Response

The immediate vascular reaction occurring right after injury until the threat is eliminated, involving vasodilation, vasoconstriction, phagocytosis, and fibrinogen.

Pyrogens

Substances released by bacteria or immune cells that trigger fever during a systemic inflammatory response to create an unfavorable environment for pathogens.

Interferons

Proteins released by virus-infected cells that bind to nearby uninfected cells to inhibit viral replication.

Complement Proteins

Plasma proteins activated by pathogens that enhance inflammation, promote pathogen destruction, and support the immune response.

Cellular Immunity

A component of adaptive immunity driven by T cells (helper, suppressor, and cytotoxic killer T cells) that directly destroys antigens.

Humoral Immunity

A component of adaptive immunity where B cells produce antibodies against antigens starting $72\,\text{hours}$ after initial exposure.

Immune Dimorphism

The biological condition in which the sexes respond differently to infection and vaccination.

Immune Senescence

The age-related decline in immune response characterized by lower B- and T-cell production and increased apoptosis of these cells.

Type I Hypersensitivity

An immediate, IgE-mediated local or systemic reaction requiring prior sensitization, characterized by mast cell and basophil activation and histamine release.

Type II Hypersensitivity

A cytotoxic antibody-mediated reaction where IgG or IgM antibodies bind to self cells, causing complement activation and cell lysis or phagocytosis.

Type III Hypersensitivity

An immune complex-mediated reaction where antigen-antibody complexes form and deposit in tissues, triggering complement activation and inflammatory tissue damage.

Type IV Hypersensitivity

A delayed, T-cell-mediated hypersensitivity response involving no antibodies, triggered by hapten exposure such as poison ivy.

Erythroblastosis Fetalis

A Type II cytotoxic hypersensitivity condition where maternal anti-Rh antibodies cross the placenta during a subsequent pregnancy with an Rh+ fetus, attacking and destroying fetal Rh+ red blood cells.

Allogeneic Transplant

A transplant between a donor and recipient who are related or unrelated but share similar tissue types; it is the most common transplant method.

Syngeneic Transplant

A tissue transplant performed between identical twins.

Autologous Transplant

A transplant where the donor and recipient are the same person; recognized as the most successful transplant method.

Xenogenic Transplant

A tissue transplant performed between individuals of different species.

Hyperacute Tissue Rejection

A nearly immediate transplant rejection response driven by the complement system that results in tissue necrosis.

Acute Tissue Rejection

A treatable transplant reaction occurring within $3\,\text{months}$ of transplantation, presenting with fever and edema.

Chronic Tissue Rejection

An antibody-mediated transplant rejection occurring from $4\,\text{months}$ onward, caused by ischemia in the vessel walls of transplanted tissue.

Systemic Lupus Erythematosus

A chronic stress-related inflammatory autoimmune disease affecting connective tissue, driven by B cells producing autoantibodies and autoantigens.

Primary Immunodeficiency

A diminished or absent immune response caused directly by a defect within the immune system itself.

Secondary Immunodeficiency

A diminished or absent immune response caused by an underlying disease or external factor suppressing the immune system.

Human Immunodeficiency Virus

A retrovirus that infects CD4 cells and macrophages, transmitted via blood and bodily fluids (excluding saliva), with HIV-1 being the most prevalent strain in the United States.

Category 3 CD4 Count

A lab-based CD4 cell count categorization defined as less than $200\,\text{cells}/\mu\text{L}$, indicating severe immunodeficiency.

General Adaptation Syndrome

A predictable, systemic physiological response to stress consisting of three stages: alarm stage, resistance stage, and exhaustion stage.

Local Adaptation Syndrome

A localized stress response mechanism that confines damage or inflammation to one specific area.