Unit objectives

Lymphatic System

Flashcard 1
Front: What are the main functions of the lymphatic system?
Back: Fluid recovery (returns fluid to blood), immunity (lymphocytes defend against pathogens), and lipid absorption (absorbs fats from intestines).

Flashcard 2
Front: How does lymph form and what is its composition?
Back: Lymph forms from interstitial fluid entering lymphatic capillaries. It’s similar to plasma but with fewer proteins.

Flashcard 3
Front: Trace the flow of lymph from its origin to where it reenters the bloodstream.
Back: Lymphatic capillaries → collecting vessels → lymphatic trunks → collecting ducts → subclavian veins.

Flashcard 4
Front: What are the two main lymphatic ducts and what areas do they drain?
Back:

• Right lymphatic duct: drains right arm, right side of head, and thorax.

• Thoracic duct: drains the rest of the body.

Flashcard 5
Front: What is the role of the primary lymphatic organs?
Back: Sites where lymphocytes mature — red bone marrow (B cell maturation) and thymus (T cell maturation).

Flashcard 6
Front: What are the secondary lymphatic organs and their functions?
Back: Lymph nodes, spleen, and tonsils — they trap pathogens and are sites of immune responses.

Flashcard 7
Front: What are the major functions of lymph nodes?
Back: Filter lymph, trap pathogens, and activate lymphocytes to trigger immune responses.

Flashcard 8
Front: How does the spleen contribute to immunity and blood maintenance?
Back:

• Red pulp: filters blood, removes old RBCs, and stores platelets.

• White pulp: contains lymphocytes for immune responses.

Innate and Adaptive Immunity

Flashcard 9
Front: What are the two main types of immunity?
Back:

• Innate immunity: non-specific defense present at birth (e.g., skin, inflammation).

• Adaptive immunity: specific, acquired immunity involving T and B cells.

Flashcard 10
Front: What are the differences between humoral and cellular immunity?
Back:

• Humoral immunity: B cells produce antibodies to neutralize pathogens.

• Cellular immunity: T cells directly attack infected or abnormal cells.

Flashcard 11
Front: What is an antigen and how does it trigger an immune response?
Back: An antigen is a molecule that triggers an immune response by binding to receptors on lymphocytes.

Flashcard 12
Front: How do antigen-presenting cells (APCs) work?
Back: APCs (like macrophages, B cells, dendritic cells) process antigens and present them to T cells using MHC proteins.

Flashcard 13
Front: What are the major classes of T cells and their functions?
Back:

• Cytotoxic T cells (Tc): attack infected or abnormal cells.

• Helper T cells (Th): activate B cells and other T cells.

• Regulatory T cells (Treg): suppress immune responses to prevent autoimmunity.

• Memory T cells: provide long-term immunity.

Flashcard 14
Front: What is clonal selection and why is it important?
Back: When a B or T cell binds to its antigen, it proliferates into clones that fight the pathogen, ensuring a strong immune response.

Immune Responses

Flashcard 15
Front: What are the steps of the humoral immune response?
Back:

1. B cell binds to antigen.

2. Helper T cell activates the B cell.

3. B cell proliferates and differentiates into plasma cells.

4. Plasma cells secrete antibodies.

Flashcard 16
Front: What is the role of plasma cells?
Back: Plasma cells are B cells that secrete antibodies specific to the antigen.

Flashcard 17
Front: What are the five classes of antibodies and their functions?
Back:

• IgG: most abundant, crosses placenta.

• IgA: in mucus and secretions.

• IgM: first produced during infection.

• IgE: involved in allergies.

• IgD: B cell activation.

Flashcard 18
Front: What are the four ways antibodies work?
Back:

• Neutralization: blocks pathogen binding.

• Opsonization: marks pathogens for destruction.

• Agglutination: clumps pathogens together.

• Complement activation: triggers pathogen lysis.

Flashcard 19
Front: What are the steps of cell-mediated immunity?
Back:

1. Cytotoxic T cell binds to infected cell.

2. Releases perforins and granzymes.

3. Infected cell is destroyed.

Hypersensitivity and Disorders

Flashcard 20
Front: What are the four types of hypersensitivity reactions?
Back:

• Type I (IgE-mediated): allergies.

• Type II (antibody-mediated): cell lysis.

• Type III (immune complex): tissue damage.

• Type IV (delayed): T cell-mediated (e.g., poison ivy).

Flashcard 21
Front: What is anaphylaxis and how is it treated?
Back: Severe allergic reaction causing systemic vasodilation and bronchoconstriction; treated with epinephrine.

Flashcard 22
Front: What causes autoimmune diseases?
Back: The immune system attacks the body's own tissues due to loss of self-tolerance.

Flashcard 23
Front: What are some examples of autoimmune diseases?
Back: Rheumatoid arthritis, lupus, multiple sclerosis.