Immunity and Stress Lecture Flashcards

Comprehensive vocabulary flashcards covering innate and adaptive immunity, hypersensitivity types, transplant rejections, autoimmune disorders, HIV/AIDS, and physiological stress responses.

Antigens

Nonself molecules or substances that trigger an immune response.

Innate Immunity

The body's immediate, nonspecific defense system that recognizes nonself using skin, mucous membranes, chemicals, and the microbiome without targeting specific pathogens.

Inflammatory Response

A second line of defense involving a vascular reaction triggered by mast cells following injury or trauma, following a nondiscriminatory sequence.

Acute Phase of Inflammation

The stage of the inflammatory response occurring immediately after injury until the threat is eliminated, featuring vasodilation, vasoconstriction, phagocytosis, and fibrinogen.

Chronic Phase of Inflammation

The stage of inflammation that lasts until healing is complete when the acute phase fails to resolve an issue, often occurring in the presence of resistant organisms.

Histamines

Chemicals released by damaged tissues that increase blood flow and cause capillaries to leak, releasing phagocytes and clotting factors into the wound.

Phagocytes

Immune cells that move into wounded areas to engulf bacteria, dead cells, and cellular debris.

Platelets

Blood elements that move out of capillaries to seal a wounded area.

Pyrogens

Substances released by bacteria or immune cells that trigger fever 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 aid the immune response.

Adaptive Defenses

Acquired immune responses specific to individual organisms that distinguish self from nonself and develop immunological memory over time.

Cellular Immunity

An adaptive defense mechanism mediated by T cells that directly destroys antigens.

T Cells

White blood cells produced in bone marrow and matured in the thymus, categorized into regulator cells (helper T and suppressor T) and effector cells (cytotoxic killer T cells).

Humoral Immunity

An adaptive defense mechanism mediated by B cells that produces antibodies against specific antigens.

B Cells

Immune cells that form memory cells and immunoglobulin-secreting cells, producing antibodies 72 hours after initial exposure to an antigen.

Maternal IgG

Maternal antibodies transferred to infants that grant temporary passive immunity for 3 to 6 months, though with low affinity.

Immune Dimorphism

The differential immune response to infection and vaccination based on biological sex.

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 triggered by allergen exposure, causing mast cell and basophil activation and histamine release.

Type II Hypersensitivity

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

Type III Hypersensitivity

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

Type IV Hypersensitivity

A delayed, T-cell-mediated reaction without antibody involvement, driven by cytokine release, macrophage activation, and tissue injury or fibrosis.

Erythroblastosis Fetalis

A Type II hypersensitivity condition where maternal anti-Rh antibodies cross the placenta and attack fetal Rh+ red blood cells.

Allogeneic Transplant

The most common type of transplant, where the donor and recipient are related or unrelated individuals with similar tissue types.

Syngeneic Transplant

A tissue or organ transplant conducted between identical twins.

Autologous Transplant

The most successful transplant method, where the donor and recipient are the same person.

Xenogenic Transplant

A tissue or organ transplant conducted between members of different species.

Hyperacute Tissue Rejection

A nearly immediate tissue rejection caused by the complement system that leads to necrosis.

Acute Tissue Rejection

A treatable transplant rejection occurring within 3 months, manifesting as fever and edema.

Chronic Tissue Rejection

An antibody-mediated tissue rejection occurring from 4 months onward due to ischemia in the vessel walls of the transplanted tissue.

Autoimmunity

A disorder in which the immune system fails to recognize self and mounts an immune response against the body's own tissue.

Systemic Lupus Erythematosus (SLE)

A chronic stress-related inflammatory autoimmune disorder affecting connective tissue and multiple organ systems, driven by autoantibodies produced by B cells.

Primary Immunodeficiency

An immunodeficiency caused by a direct defect within the immune system itself.

Secondary Immunodeficiency

An immunodeficiency caused by an underlying disease or external factor suppressing the immune system.

Human Immunodeficiency Virus (HIV)

A retrovirus transmitted via blood and bodily fluids that infects CD4 cells and macrophages.

HIV-1

The most prevalent strain of HIV in the United States.

Nucleic Acid Tests (NAT)

Expensive and nonroutine diagnostic tests used to detect viral load in HIV patients.

CD4 Category 3

A laboratory categorization of HIV progression indicating a CD4 cell count of less than $200\,\text{cells}/\mu\text{L}$, representing AIDS.

General Adaptation Syndrome

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

Local Adaptation Syndrome

A localized stress response that confines damage to a single area.