Immunology Basics

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Questions and Answers

What is the function of antimicrobial secretions in the innate immunity?

To trigger inflammation and promote healing

To activate the adaptive immune response

To recognize and remember specific pathogens

To directly block or lyse bacteria (correct)

Which type of cells are involved in the innate immune response and have no immunological memory?

Antigen-presenting cells and cytokines

Phagocytes and natural killer cells (correct)

T cells and B cells

Dendritic cells and macrophages

What is the primary function of the complement system?

To prevent autoimmune diseases

To trigger an adaptive immune response

To recognize and eliminate specific pathogens

To trigger inflammation and kill pathogens by cytolysis (correct)

What is the term for an overactive immune system?

Allergy Signup and view all the answers

What is the term for the body's first line of defense against pathogens?

Innate immunity Signup and view all the answers

Which of the following is NOT a function of the immune system?

Producing hormones Signup and view all the answers

What is the term for the process of preventing or reducing the severity of infectious diseases?

Vaccination Signup and view all the answers

What is the term for the physical and chemical barriers that prevent pathogens from entering the body?

All of the above Signup and view all the answers

What is the primary function of CD4+ T cells?

To secrete cytokines to coordinate immune response Signup and view all the answers

What is the outcome of an overactive immune system?

Allergies and autoimmune diseases Signup and view all the answers

What is the role of phagocytes in the immune response?

To engulf and destroy pathogens Signup and view all the answers

What type of hypersensitivity is mediated by IgE and mast cells?

Type I - Acute Signup and view all the answers

What is the result of an underactive immune system?

Immunodeficiency disorders Signup and view all the answers

What is the function of CD8+ T cells?

To kill target cells Signup and view all the answers

What type of hypersensitivity involves the recruitment of macrophages and eosinophils?

Type IV - Cell-mediated Signup and view all the answers

What is the result of immune system mistakenly attacking the body's own tissues and cells?

Autoimmune diseases Signup and view all the answers

What is the role of TNFa in the immune response?

Implicated in inflammation Signup and view all the answers

What is the main function of macrophages in the immune cascade?

To phagocytose foreign substances Signup and view all the answers

What is the role of cytokines in the immune response?

To activate immune cells through receptor binding Signup and view all the answers

What is the role of neutrophils in the immune response?

To phagocytose foreign substances Signup and view all the answers

What is the role of eosinophils in the immune response?

To fight against parasites Signup and view all the answers

What is the role of mast cells in the immune response?

To release inflammatory mediators Signup and view all the answers

What is the process by which immune cells develop from stem cells?

Haematopoiesis Signup and view all the answers

What is the term for the series of reactions that occur in the body in response to a foreign substance?

Immune cascade Signup and view all the answers

What is the primary function of the immune system?

To defend the body against harmful foreign substances Signup and view all the answers

What is immunology?

The study of the immune system and its functions Signup and view all the answers

What is the role of the adaptive immune system?

To provide a longer-term response that is specifically tailored to the invading pathogen Signup and view all the answers

What is the term for the complex network of cells, tissues, and organs that work together to defend the body?

Immune system Signup and view all the answers

What are the two main types of immune systems?

Innate and adaptive Signup and view all the answers

What type of immune response is characterized by a rapid response to infections?

Innate immune response Signup and view all the answers

What is the term for the cells involved in the immune response?

Leukocytes Signup and view all the answers

What is the term for the mucosa-associated lymphoid tissue?

MALT Signup and view all the answers

What is the primary function of macrophages in the immune system?

To stay in connective tissue and phagocytose foreign particles Signup and view all the answers

Which type of cell is responsible for cell-mediated immunity?

T cells Signup and view all the answers

What is the primary function of NK cells in the immune system?

To target and kill infected and cancer cells Signup and view all the answers

What is the role of dendritic cells in the immune system?

To present antigens to T cells in lymph nodes Signup and view all the answers

What is the primary function of B cells in the immune system?

To produce antibodies against pathogens Signup and view all the answers

What is the role of monocytes in the immune system?

To differentiate into macrophages and dendritic cells Signup and view all the answers

Where do T cells complete their development?

Thymus Signup and view all the answers

What is the role of antigen presentation in the immune system?

To activate T cells to target infected cells Signup and view all the answers

Study Notes

Immunology

Immunology is the study of the immune system and its functions.
The immune system plays a crucial role in maintaining health by defending against pathogens and potentially harmful substances.
When the immune system malfunctions, it can lead to diseases such as allergies and autoimmune disorders.

Key Terms in Immunology

Immune system: a complex network of cells, tissues, and organs that work together to defend the body against harmful foreign substances.
Components of the immune system:
Innate immune system: provides a rapid response to infections.
Adaptive immune system: provides a longer-term response that is specifically tailored to the invading pathogen.
Cells: leukocytes (white blood cells), including neutrophils, macrophages, monocytes, dendritic cells, natural killer cells, and lymphocytes (B cells and T cells).
Tissues and organs: lymph nodes, spleen, thymus, bone marrow, mucosa-associated lymphoid tissue (MALT), gut-associated lymphoid tissue (GALT), bronchial-associated lymphoid tissue (BALT), and skin-associated lymphoid tissue (SALT).
Molecules: antibodies, cytokines, complement, and major histocompatibility complex (MHC) molecules.

Innate Immunity

Innate immunity: the body's first line of defense against pathogens.
Non-specific cells: phagocytes, natural killer (NK) cells (myeloid cells); no immunological memory.
Physical and chemical barriers:
Skin and mucus (pH)
Stomach acid (~pH2)
Antimicrobial secretions (lysozymes), lactoferrin, defensins, and peroxidases
Inflammation: stops the spread of infection, promotes healing, and has four cardinal signs: redness, heat, swelling, and pain.
Complement system: a cascade of proteins that triggers inflammation and kills pathogens by cytolysis.
IFNg: an important macrophage activator.
TNFa: important in inflammation.

Adaptive Immunity

Adaptive immunity: a longer-term response that is specifically tailored to the invading pathogen.
Cytokines: signalling molecules that regulate the immune response.

Cells of the Immune System

Leukocytes (white blood cells):
Formed by haematopoiesis in bone marrow.
Start with multipotent haemopoietic stem cells (SC).
Cells develop into myeloid/lymphoid progenitor cells.
Myeloid cells: contribute to innate response.
Neutrophils: phagocytes, granulocytes, polymorphonuclear cells (nucleus segmented into 3-5 lobes).
Eosinophils: phagocytes, granulocytes, polymorphonuclear cells (nucleus usually bilobed).
Basophils: non-phagocytic, granulocytes, polymorphonuclear cells (nucleus bilobed/segmented).
Mast cells: non-phagocytes, granulocytes, involved in inflammatory response.
Monocytes: phagocytes, antigen presenting cells, release cytokines to recruit other cells.
Dendritic cells: phagocytes, antigen presenting cells, release cytokines to recruit other cells.
Macrophages: phagocytes, antigen presenting cells, release cytokines to recruit other cells.
Lymphoid cells: contribute to the adaptive response (except NK cells).
NK cells: complete development in bone marrow, contribute to innate response.
B cells: complete development in bone marrow, bind to specific antigens, capable of phagocytosis and antigen presentation.
T cells: complete development in thymus, responsible for cell-mediated immunity, bind to specific antigens, and require antigen presentation.

Immune Cascade

A series of reactions that occur in the body in response to a foreign substance.
Involves the activation, recruitment, and action of various immune cells and molecules.
Importance in health and disease: crucial for eliminating pathogens, but can also contribute to inflammation and tissue damage if not properly regulated.

Immune System Disorders

Role of immune system in diseases:
An overactive immune system can lead to allergies and autoimmune diseases.
An underactive immune system can result in immunodeficiency disorders.
Types of hypersensitivity:
I - Acute (allergic; anaphylactic; immediate; reaginic)
II - Antibody mediated (cytotoxic)
III - Antigen-antibody complex mediated
IV - Cell-mediated (delayed; tuberculin-type)

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Description

Learn about the fundamentals of immunology, including the terminology, role, and components of the immune system. Understand the importance of immunology in health and disease.