Immunology

Question 1

What is phagocytosis?

Answer 1

The process by which phagocytes engulf and digest foreign particles or disease-causing organisms.

Question 2

name 2 types of phagocytic white blood cells

Answer 2

neutrophils
macrophages/monocytes

Question 3

what role do phagocytes play as antigen-presenting cells?

Answer 3

They break up foreign particles into components, display these on their membrane, and activate T helper cells.

Question 4

which cells produce histamine and what is its function?

Answer 4

Basophils and mast cells produce histamine, which increases capillary permeability to facilitate immune responses.

Question 5

what are the 3 ways mast cells can be activated?

Answer 5

Direct injury
binding to IgE antibodies
activated complement proteins.

Question 6

where do B lymphocytes mature?

Answer 6

B lymphocytes mature in the bone marrow and produce antibodies in response to antigens.

Question 7

how do T lymphocytes differ from B lymphocytes in antigen recognition?

Answer 7

T cells recognize antigens bound to MHC proteins, while B cells directly bind to antigens.

Question 8

describe the role of T helper cells

Answer 8

They activate other immune cells such as macrophages, B cells, and cytotoxic T cells to respond to antigens.

Question 9

what is the function of T cytotoxic cells?

Answer 9

To eliminate virus-infected cells, tumor cells, and foreign grafts.

Question 10

what is the difference between humoral and cell mediated immunity?

Answer 10

Humoral immunity involves B cells and antibodies against extracellular pathogens, while cell-mediated immunity involves T cells and targets intracellular pathogens.

Question 11

what are antibodies and what is their structure?

Answer 11

Antibodies are Y-shaped glycoproteins made of four polypeptide chains (two heavy and two light), held together by disulfide and non-covalent bonds.

Question 12

list the 5 types of antibodies

Answer 12

IgM
IgE
IgG
IgA
IgD

Question 13

what is the main role of IgG antibodies?

Answer 13

They detoxify harmful substances and are transferred across the placenta to protect the fetus.

Question 14

how are monoclonal antibodies produced?

Answer 14

Through the hybridoma method, combining specific B cells with myeloma cells to produce identical antibodies.

Question 15

what are monoclonal antibodies used for in pregnancy testing kits?

Answer 15

They detect the hormone HCG, produced by the early embryo.

Question 16

what is chemotaxis in the context of phagocytosis?

Answer 16

The movement of phagocytes towards the site of infection in response to chemical signals from pathogens.

Question 17

what are the 4 main steps in phagocytosis?

Answer 17

Activation and chemotaxis, recognition of microbes, ingestion, and destruction of the pathogen.

Question 18

what function do pseudopods serve during phagocytosis?

Answer 18

They are extensions of the phagocyte’s cytoplasm that surround and engulf foreign particles, forming a vacuole.

Question 19

what is the role of the complement proteins in phagocytosis?

Answer 19

They help attract microorganisms to the phagocyte’s membrane to facilitate engulfment.

Question 20

how do mast cells contribute to allergic reactions?

Answer 20

They release histamine and other chemicals, causing blood vessel expansion, itching, and mucus buildup.

Question 21

what are memory B cells and why are they important?

Answer 21

Memory B cells are long-lived cells that remain in the bloodstream, enabling a rapid immune response if the same antigen is encountered again.

Question 22

what distinguishes T memory cells from other T lymphocytes?

Answer 22

T memory cells have a longer lifespan and can rapidly respond to previously encountered antigens.

Question 23

What is the Major Histocompatibility Complex (MHC), and why is it significant?

Answer 23

MHC is a set of proteins on cell membranes that present antigens to T cells, crucial for immune recognition.

Question 24

How does IgA contribute to he body’s defense?

Answer 24

It is found in mucosal areas, such as saliva and breast milk, providing the first line of defense against pathogens.

Question 25

what is the primary role of IgE antibodies?

Answer 25

They are involved in allergic responses and protect against parasitic infections.

Question 26

Explain the difference between IgM and IgD antibodies

Answer 26

IgM is the first antibody produced during an immune response and is involved in agglutination, while IgD is involved in the activation of B cells.

Question 27

what triggers the production of antibodies by B lymphocytes?

Answer 27

The binding of a specific antigen to the membrane-bound immunoglobulin (B cell receptor) on the B lymphocyte.

Question 28

what hapens during the differentiation of B cells into plasma cells?

Answer 28

The B cells lose their surface antibody and begin producing large amounts of specific antibodies to fight infections.

Question 29

what is the role of cytokines in cell-mediated immunity?

Answer 29

They are signaling molecules that help regulate immune responses by activating T cells, macrophages, and other immune cells.

Question 30

why is humoral immunity considered faster than cell mediated immunity?

Answer 30

Humoral immunity involves the rapid production of antibodies against extracellular pathogens, while cell-mediated immunity targets intracellular pathogens, requiring more complex cellular interactions

Question 31

what are the roles of neutrophils in the immune response?

Answer 31

Neutrophils are a type of phagocyte that make up about 60% of white blood cells. They are one of the first responders to infection and help by engulfing and destroying pathogens.

Question 32

how do macrophages differ from neutrophils in their immune function?

Answer 32

While both are phagocytes, macrophages are larger, live longer, and are present in higher numbers in tissues like the liver. They also act as antigen-presenting cells, playing a crucial role in activating adaptive immunity.

Question 33

what is agglutination and how do antibodies contribute to this process?

Answer 33

Agglutination is the clumping together of pathogens. Antibodies, especially IgM, bind to antigens on the surface of pathogens, making them easier targets for phagocytes.

Question 34

why are monoclonal antibodies highly specific to their target antigens?

Answer 34

They are produced by identical immune cells cloned from a single parent cell, ensuring that all the antibodies recognize the same specific antigen.

Question 35

what is the significance of CD4 and CD8 proteins in T cells?

Answer 35

CD4 proteins are found on T helper cells and help recognize antigens presented by MHC class II molecules. CD8 proteins are on T cytotoxic cells and recognize antigens presented by MHC class I molecules.

Question 36

how does the complement system enhance the immune response?

Answer 36

The complement system consists of proteins that enhance the ability of antibodies and phagocytic cells to clear pathogens, promote inflammation, and attack the pathogen's cell membrane.

Question 37

explain the concept of clonal selection in adaptive immunity

Answer 37

When a B or T cell encounters its specific antigen, it is activated to proliferate and form a clone of cells specific to that antigen. This process is essential for the adaptive immune response.

Question 38

what roles do memory cells play in vaccination?

Answer 38

Vaccination induces the formation of memory cells that remain in the body and provide long-term protection by mounting a rapid response if the pathogen is encountered again.

Question 39

how do plasma cells differ from memory B cells?

Answer 39

Plasma cells are differentiated B cells that produce and secrete large quantities of antibodies during an active infection, while memory B cells remain in the bloodstream to provide immunity for future exposures.

Question 40

describe how allergic reactions are triggered in the immune system

Answer 40

Allergic reactions occur when mast cells, activated by IgE antibodies bound to allergens, release histamine and other mediators that cause symptoms such as swelling, itching, and mucus production.

Question 41

what is the role of antigen presenting cells in the immune system?

Answer 41

APCs, such as macrophages, dendritic cells, and B cells, process and display antigens on their surface to activate T cells, linking the innate and adaptive immune responses.

Question 42

how does humoral immunity protect against extracellular pathogens?

Answer 42

Humoral immunity involves the production of antibodies that circulate in the blood and lymph, neutralizing pathogens and marking them for destruction by other immune cells.

Question 43

what are the potential herapeutic uses of monoclonal antibodies?

Answer 43

Monoclonal antibodies can be used in cancer treatment, autoimmune disease management, and infectious disease therapy by specifically targeting diseased cells or harmful pathogens.

Question 44

why is the variable region of an antibody important?

Answer 44

The variable region allows antibodies to bind specifically to different antigens, providing the immune system with the ability to recognize a vast array of pathogens.

Question 45

what are cytokines and what role do they play in immunity?

Answer 45

Cytokines are signaling proteins released by immune cells that facilitate communication and coordination during immune responses, such as inflammation and activation of lymphocytes.

Question 46

what is the role of the thymus in the immune system?

Answer 46

The thymus is where T lymphocytes mature and differentiate, which is crucial for developing a functional adaptive immune response.

Question 47

how do antibodies neutralize toxins?

Answer 47

Antibodies can bind to toxins produced by pathogens, preventing them from interacting with host cells and neutralizing their harmful effects.

Question 48

what distinguishes natural immunity from artificial immunity?

Answer 48

Natural immunity is acquired through natural exposure to pathogens, while artificial immunity is obtained through medical interventions, such as vaccines or antibody injections.