Immune System Flashcards
(20 cards)
Overview of the Immune System
Function: Protects the body from harmful pathogens, such as bacteria, viruses, and fungi.
Components: White blood cells, antibodies, lymphatic system, spleen, bone marrow, thymus.
Types of Immunity: Innate (non-specific) and adaptive (specific).
Cue Card 2: Innate Immunity
Innate Immunity
Definition: The first line of defense, non-specific, and immediate.
Components:
- Skin and mucous membranes.
- Phagocytes (e.g., neutrophils, macrophages).
- Natural killer cells.
- Inflammatory response.
- Complement proteins.
Adaptive Immunity
Definition: Specific immunity that develops after exposure to pathogens.
Key Cells:
- B Lymphocytes: Produce antibodies.
- T Lymphocytes: Directly attack infected cells (cytotoxic T cells) or help activate other immune cells (helper T cells).
Characteristics: Specificity and memory.
White Blood Cells (Leukocytes)
Types of WBCs:
Neutrophils: First responders, engulf pathogens.
Lymphocytes: T cells, B cells, and natural killer (NK) cells.
Monocytes: Become macrophages, phagocytose pathogens.
Eosinophils: Fight parasites and allergic reactions.
Basophils: Release histamine during allergic reactions.
B Lymphocytes (B Cells)
Function: Produce antibodies to neutralize pathogens.
Plasma Cells: Differentiated B cells that secrete large amounts of antibodies.
Memory B Cells: Retain information about past infections for faster responses during reinfection.
T Lymphocytes (T Cells)
Types of T Cells:
- Helper T Cells (CD4+): Activate B cells and cytotoxic T cells.
- Cytotoxic T Cells (CD8+): Destroy virus-infected or cancerous cells.
- Regulatory T Cells: Suppress immune responses to prevent overreaction.
Origin: Produced in the bone marrow, mature in the thymus.
Antibodies (Immunoglobulins)
Function: Bind to specific antigens on pathogens to neutralize them.
Types of Antibodies:
IgG: Most common; provides long-term immunity.
IgA: Found in mucous membranes, saliva, and breast milk.
IgM: First antibody produced in response to an infection.
IgE: Involved in allergic reactions.
IgD: Functions in B cell activation.
Primary Immune Response
Definition: The body’s initial response to a new pathogen.
Characteristics: Slower response; B cells produce IgM first, followed by IgG.
Memory Cells: Created to respond more quickly to future encounters with the same pathogen.
Secondary Immune Response
Definition: The body’s rapid and stronger immune response upon re-exposure to the same pathogen.
Characteristics: Faster due to memory B and T cells; mainly IgG antibodies are produced.
Vaccination
Definition: Introduction of a weakened or inactivated pathogen to stimulate the immune system.
Purpose: Generates memory cells without causing disease.
Examples: MMR (measles, mumps, rubella), influenza, and COVID-19 vaccines.
Inflammation
Definition: A localized protective response to injury or infection.
Signs: Redness, heat, swelling, pain, and loss of function.
Phases:
Acute Inflammation: Immediate response to injury.
Chronic Inflammation: Prolonged response, can lead to tissue damage.
The Complement System
Definition: A group of proteins that assist in pathogen destruction.
Functions:
Opsonization (tagging pathogens for destruction).
Forming the membrane attack complex (MAC) to lyse pathogens.
Enhancing inflammation.
Phagocytosis
Definition: The process of engulfing and digesting pathogens or debris.
Key Phagocytes: Neutrophils and macrophages.
Steps:
Recognition and attachment.
Engulfment into a phagosome.
Digestion and destruction of the pathogen.
Autoimmune Disorders
Definition: Conditions where the immune system mistakenly attacks the body’s own cells.
Examples:
Rheumatoid arthritis.
Systemic lupus erythematosus (SLE).
Type 1 diabetes mellitus.
Treatment: Immunosuppressive drugs, corticosteroids.
Allergic Reactions
Definition: An exaggerated immune response to a harmless substance (allergen).
Mechanism: Involves IgE antibodies and histamine release from mast cells.
Types:
Mild: Hay fever, allergic rhinitis.
Severe: Anaphylaxis, a life-threatening condition.
Immune Deficiency
Definition: A condition where the immune system’s ability to fight infections is compromised.
Types:
Primary: Genetic causes (e.g., SCID – Severe Combined Immunodeficiency).
Secondary: Acquired (e.g., HIV/AIDS).
Treatment: Antiretroviral therapy (HIV), immune-boosting treatments.
HIV and the Immune System
Definition: A virus that attacks helper T cells (CD4+ cells).
Effect: Weakens the immune system, leading to AIDS (Acquired Immunodeficiency Syndrome).
Treatment: Antiretroviral therapy (ART) to slow disease progression
Lymphatic System and Immunity
Components: Lymph nodes, lymph vessels, spleen, thymus, and tonsils.
Functions:
Filters lymph to remove pathogens and waste.
Houses and transports immune cells (e.g., lymphocytes).
Spleen: Filters blood, recycles old red blood cells, stores white blood cells.
Immunoglobulin Therapy
Definition: The administration of antibodies to boost the immune response.
Used For: Immunodeficiency disorders, autoimmune diseases, and in patients exposed to certain infections (e.g., rabies).
Route of Administration: IV or subcutaneous
Nursing Assessment of the Immune System
Patient History: Inquire about infections, allergies, vaccines, autoimmune disorders.
Physical Exam: Check for lymph node enlargement, skin rashes, signs of infection.
Diagnostic Tests:
Complete blood count (CBC) with differential.
Immunoglobulin levels.
HIV tests.
Allergy tests.
