Immune System

This set of flashcards covers the key concepts and vocabulary related to the immune system as outlined in the lecture notes.

Innate Defense System

The nonspecific defense system that comprises the first and second lines of defense against pathogens.

First Line of Defense

External body membranes, primarily the skin and mucosae, that act as a physical barrier to microorganisms.

Phagocytosis

The process by which certain cells, like phagocytes, engulf and digest pathogens and cellular debris.

Natural Killer (NK) Cells

A type of immune cell that kills cancer and virus-infected cells by inducing apoptosis.

Inflammation

A localized response triggered by tissue injury, characterized by redness, heat, swelling, and pain, aimed at protecting the body.

Antimicrobial Proteins

Proteins like interferons and complement proteins that enhance the innate immune response by attacking microorganisms.

Fever

A systemic response to infection, characterized by a rise in body temperature to inhibit pathogen growth and enhance repair processes.

Humoral Immunity

A branch of adaptive immunity involving B lymphocytes that secrete antibodies to target extracellular pathogens.

Cellular Immunity

A branch of adaptive immunity where T lymphocytes act directly against infected or cancerous cells.

Helper T Cells

Cells that activate both humoral and cellular immune responses by interacting with antigen-presenting cells.

Adaptive Immunity

A type of immunity that develops as a response to exposure to pathogens and involves the activation of lymphocytes.

B Lymphocytes (B Cells)

A type of white blood cell that produces antibodies as part of the humoral immune response.

T Lymphocytes (T Cells)

A type of white blood cell that plays a central role in adaptive immunity, including helper T cells and cytotoxic T cells.

Memory Cells

Long-lived cells that remember a specific pathogen after an initial immune response, allowing for a faster response upon re-exposure.

Antibodies

Proteins produced by B cells that specifically bind to antigens on pathogens to neutralize or mark them for destruction.

Antigen-Presenting Cells (APCs)

Cells that process and present antigens to T cells, crucial for initiating the adaptive immune response.

Cytotoxic T Cells

T cells that kill infected or cancerous cells by inducing apoptosis.

Vaccination

The administration of a vaccine to stimulate an immune response and confer protection against specific diseases.

Innate Immunity

The natural, immediate first line of defense against infections, comprising physical barriers, phagocytic cells, and various immune responses.

Phagocytosis

The process by which cells, such as macrophages and neutrophils, engulf and digest pathogens and debris.

Natural Killer (NK) Cells

A type of lymphocyte that can destroy virus-infected cells or tumor cells by inducing apoptosis.

Inflammation

A localized protective response that results in redness, heat, swelling, and pain as part of the immune response to injury or infection.

Antimicrobial Proteins

Proteins that play a key role in enhancing the innate immune defense by attacking and destroying pathogens.

Fever

An elevated body temperature that occurs in response to infection, aimed at inhibiting pathogen growth and promoting healing.

Complement System

A group of proteins that enhance the ability of antibodies and phagocytic cells to clear pathogens from an organism.

Cytokines

Small signaling proteins released by cells that mediate and regulate immunity, inflammation, and hematopoiesis.

Mucous Membrane

The tissue lining body cavities that connect to the outside environment, providing a barrier and producing mucus to trap pathogens.

Skin Flora

The community of microorganisms that live on the skin and help to protect against pathogens by competing for resources and producing antimicrobial substances.

Inflammatory Mediators

Substances released during tissue injury or infection that promote inflammation and attract immune cells to sites of infection.

Adaptive Immune Response

The immune response that is specific to particular pathogens and involves the activation of lymphocytes and the production of antibodies.

Clonal Selection

The process by which a specific immune cell is selected and expanded during an immune response to effectively target a pathogen.

Primary Immune Response

The initial response of the immune system to a new antigen, characterized by the activation of naive B and T cells and the generation of memory cells.

Pathogen

Any microorganism that can cause disease, including bacteria, viruses, fungi, and parasites.

Antigen

A substance that triggers an immune response, often identified by the immune system as foreign or harmful.

Immunoglobulin

A type of antibody produced by B cells that plays a crucial role in identifying and neutralizing pathogens.

Cytotoxicity

The capacity of certain cells to kill other cells, particularly infected or abnormal cells as part of the immune response.

Apoptosis

The process of programmed cell death that occurs in multicellular organisms, essential for development and maintaining cellular homeostasis.

Helper T Cells

A subtype of T cells that aid in the activation of B cells and cytotoxic T cells by releasing cytokines.

Naive T Cells

T cells that have not yet encountered their specific antigen and are still in a resting state.

T Cell Receptor (TCR)

A molecule found on the surface of T cells that recognizes antigens presented by Major Histocompatibility Complex (MHC) molecules.

Memory T Cells

A subset of T cells that persist long-term after an infection has been cleared and quickly respond upon re-exposure to the same antigen.

Cytokine Storm

An excessive immune response characterized by the overproduction of cytokines, which can lead to severe inflammation and tissue damage.

Major Histocompatibility Complex (MHC)

A set of cell surface proteins important for the immune system to recognize foreign molecules; MHC molecules present antigens to T cells.

Dendritic Cells

Professional antigen-presenting cells that capture, process, and present antigens to T cells, playing a crucial role in initiating immune responses.

Regulatory T Cells (Tregs)

A specialized subtype of T cells that modulate the immune response, maintaining tolerance and preventing autoimmune diseases.

Antibody Affinity

The strength of the interaction between a single antigen-binding site of an antibody and its corresponding antigen.

Neutralizing Antibody

An antibody that binds to a pathogen (like a virus) and blocks its ability to infect host cells, providing protection against disease.

Somatic Hypermutation

A process by which areas of DNA in B cells are altered to increase antibody affinity for its antigen during an immune response.