Questions and Answers
What are the three lines of defense?
What is the 1st line of defense?
Barriers at body surfaces, skin layers, chemicals in saliva, tears, mucous, etc.
What characterizes the 2nd line of defense?
Nonspecific/innate immunity, inflammation and swelling.
What is inflammation in the context of the 2nd line of defense?
Signup and view all the answers
What role do fevers play in the immune system?
Signup and view all the answers
What do complement proteins do?
Signup and view all the answers
What comprises the lymph system?
Signup and view all the answers
Where do blood cells gather before fighting infection?
Signup and view all the answers
What is the 3rd line of defense?
Signup and view all the answers
What do effector T cells do?
Signup and view all the answers
What is the role of effector B cells?
Signup and view all the answers
What happens with memory T cells and memory B cells?
Signup and view all the answers
Why can sickness return despite T and B cell memory?
Signup and view all the answers
Study Notes
Three Lines of Defense
- First line: Barriers at body surfaces, such as skin layers and chemicals in saliva and tears.
- Second line: Innate immunity, which is nonspecific and activated when the first line fails, involving inflammation and immune organs.
- Third line: Adaptive immunity, characterized by a specific response and the ability to remember past infections.
1st Line of Defense
- Comprises physical barriers like skin and chemical barriers in bodily fluids.
- Harbors beneficial bacteria that help exclude harmful pathogens.
2nd Line of Defense
- Employs nonspecific mechanisms like inflammation and swelling.
- Involves components such as complement proteins and lymphatic organs, including lymph nodes, spleen, and tonsils.
Inflammation Mechanism
- Body's response to infection increases blood flow to the affected area.
- White blood cells are recruited to localize and eliminate pathogens, often accompanied by fever.
Fever Response
- Represents systemic inflammation, beneficial for a short duration.
- High temperatures hinder bacterial survival and growth, giving the immune system time to react.
- Prolonged fever can damage healthy cells and impair enzyme function.
Complement Proteins
- Attack bacterial cells by piercing their membranes, leading to cell death.
- They remain inactive in circulation until they encounter a pathogen.
Lymphatic System
- Comprises lymph nodes and vessels that filter and return tissue fluid to the bloodstream.
- Functions in fat transport and immune defense, evident when lymph nodes swell in response to infection.
Areas for Blood Cells
- Blood cells reside primarily in lymph nodes, spleen, and tonsils before being activated in response to infection.
3rd Line of Defense
- Involves a highly specific adaptive immune response, functioning with memory and rapid response capabilities.
- Engages effector T and B cells for effective immune action.
Effector T Cells
- Stimulate the proliferation of white blood cells.
- Release signaling chemicals to enhance the immune response in the lymph nodes.
Effector B Cells
- Produce antibodies tailored to specific pathogens such as bacteria and fungi.
- The antibody response takes time as the immune system must identify the correct type.
Memory T and B Cells
- Store information about specific antibodies needed for previously encountered pathogens.
- Remain inactive until re-exposure, leading to a quicker response and preventing future illness.
- Memory duration varies, affecting immunity against specific diseases.
Reasons for Recurring Illness
- Pathogen evasion occurs through mutations that alter receptor types and markers on cells.
- Previous antibodies may be ineffective against new strains, necessitating the generation of new antibodies.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers the key concepts of the immune system, focusing on its three lines of defense. It includes definitions and explanations of the first, second, and third lines of defense, detailing how they work together to protect the body. Ideal for students studying immunology or related biological sciences.
