Immune System 4e Fall 2022 NOTES

Immune System

The body's defense system against infectious agents and harmful substances.

Pathogens

Agents that cause disease, including bacteria, viruses, fungi, protozoans, and multicellular parasites.

Vaccination

The process of introducing a vaccine into the body to stimulate an immune response against a specific pathogen.

Allergies

Hypersensitive immune responses to substances that normally do not provoke a response.

Innate Immunity

The first line of defense that is non-specific and includes barriers such as skin and mucosal membranes.

Adaptive Immunity

A specific immune response that is activated by exposure to a specific antigen, involving T-lymphocytes and B-lymphocytes.

Cytokines

Small proteins that regulate and facilitate immune system activity, acting like hormones for immune cells.

Interleukins (IL)

A category of cytokines that regulate immune cells.

Histamine

A chemical involved in immune responses that causes blood vessels to dilate and become more permeable.

Phagocytosis

The process by which certain immune cells engulf and digest pathogens.

Complement System

A group of proteins that enhance the immune response, promoting inflammation and cellular lysis.

Antibodies

Proteins produced by B-lymphocytes that bind to antigens to neutralize them or mark them for destruction.

T-lymphocytes

A type of white blood cell that plays a central role in cell-mediated immunity.

B-lymphocytes

A type of white blood cell that is responsible for antibody-mediated immunity.

Antigenic Determinants/Epitopes

Specific parts of antigens recognized by immune receptors.

Immunoglobulin A (IgA)

An antibody found in mucosal areas such as the gut, respiratory tract, and urogenital tract, as well as in saliva, tears, and breast milk.

Active Immunity

Immunity that develops as a result of an immune response to a pathogen or vaccine.

Passive Immunity

Immunity obtained from another individual, typically through maternal antibodies during pregnancy or breastfeeding.

Herd Immunity

Resistance to the spread of a contagious disease within a population when a high percentage of individuals are immune.

What is the purpose of vaccination/immunizations?

To stimulate the immune system to develop active immunity against specific pathogens, thereby preventing disease.

What are allergies and how do they relate to the immune system?

Allergies are hypersensitive reactions of the immune system to typically harmless substances, known as allergens. They occur when the immune system mistakenly identifies these substances as threats, triggering an immune response that can cause symptoms ranging from mild to severe.