Adaptive Immune System Flashcards

Flashcards reviewing key concepts of the adaptive immune system, including specific detectors, antigen presentation, and immune cell education.

Adaptive Immune System

The third line of defense, activated when the innate immune system is breached. It involves specific detectors that tag and label invaders.

Specific Detectors (Adaptive Immune System)

Bind specifically to foreign invaders, block attachment (neutralizing), mobilize pathogens, and facilitate NK cell-mediated killing.

Neutralizing Function

Can block toxins, viruses, or bacteria from sticking, preventing infection.

Antigens

Most antigens are relatively large molecules, and there'll be multiple little bits so our immune system can recognize antigens in two main ways, either in their normal three-dimensional shape or chopped up on their cell surface

Antigen Presentation

Body cells break antigens into pieces and display them on their surface to signal the immune system.

Education Phase (Immune Cells)

Pre-B and pre-T cells learn to differentiate between self and non-self antigens to prevent attacking the body's own cells.

Self-Reactive Cell Elimination

During development, cells that bind to self-antigens receive a death signal to eliminate self-reactive cells.

B Cell Circulation

B cells circulate between blood and lymph nodes after surviving the education phase.

B Cell Activation

Activation of B cells by binding to matching antigens, leading to proliferation and differentiation into plasma and memory cells.

Plasma Cells

Secrete antibodies that circulate in the blood and lymph, binding to antigens and marking them for destruction.

Memory Cells

Long-lived cells that remember specific antigens, providing a faster and stronger response upon subsequent exposure.

T Cells

Originate from bone marrow and mature in the thymus; includes helper, cytotoxic, and regulatory types.

Helper T Cells

Enhance immune responses by activating B cells, cytotoxic T cells, and macrophages; releases cytokines to coordinate the immune response.

Cytotoxic T Cells

Kill infected or cancerous cells by recognizing foreign antigens on their surface.

Regulatory T Cells

Suppress the immune response to prevent excessive inflammation and autoimmunity; helps maintain immune homeostasis.

Cytokines

Soluble proteins secreted by immune cells that act as signaling molecules, coordinating immune responses.

MHC Class I

Presents intracellular antigens (e.g., viral proteins) to cytotoxic T cells; found on all nucleated cells.

MHC Class II

Presents extracellular antigens to helper T cells; found on antigen-presenting cells (APCs) like dendritic cells, macrophages, and B cells.

Dendritic Cells

Specialized APCs that capture antigens in tissues and migrate to lymph nodes to present them to T cells.

Antibody Structure

Y-shaped proteins with antigen-binding sites at the tips of the 'Y' and a constant region that interacts with immune cells.

IgG

Most abundant antibody in serum; provides long-term immunity and can cross the placenta to protect the fetus.

IgM

First antibody produced during an immune response; effective at activating the complement system.

IgA

Found in mucosal secretions (e.g., saliva, tears, breast milk); provides protection at mucosal surfaces.

IgE

Involved in allergic reactions and parasitic infections; binds to mast cells and basophils.

IgD

Found on the surface of B cells; involved in B

Adaptive Immune System

The third line of defense, activated when the innate immune system is breached. It involves specific detectors that tag and label invaders.

Specific Detectors (Adaptive Immune System)

Bind specifically to foreign invaders, block attachment (neutralizing), mobilize pathogens, and facilitate NK cell-mediated killing.

Neutralizing Function

Can block toxins, viruses, or bacteria from sticking, preventing infection.

Antigens

Most antigens are relatively large molecules, and there'll be multiple little bits so our immune system can recognize antigens in two main ways, either in their normal three-dimensional shape or chopped up on their cell surface

Antigen Presentation

Body cells break antigens into pieces and display them on their surface to signal the immune system.