Immunity Flashcards
Define antibody
A blood protein produced in response to and counteracting a specific antigen
Define antigen
A substance that is recognised by the immune system as self or non self and simulate an immune response
What is the difference between cell mediated immunity and antibody mediated immunity
Cell mediated response is associated with t lymphocytes destroying causative agents without producing antibodies. Antibody mediated response is associated with b lymphocytes destroying causative agents by producing antibodies against it
What are the 5 stages and cells involved in the body’s response to an antigen
-use of physical and chemical barriers
-inflammation
-phagocytosis
-actions of T cells
-actions of B cells
What is the role of t and b memory cells in the secondary immune response
They trigger a stronger and more rapid immune response after encountering the same antigen
What are the 2 main types of T cells, where do they mature and what do they do
Mature in the thymus gland, the two main type are t helper and t cytotoxic cells. Their role is to reactivate b cells after activation by a specific pathogen in the past
where do b cells mature and what do they do
Mature in the bone marrow and are associated with humoral immunity
What do b cell plasma cells do
they secrete antibodies into the blood plasma which leads to the destruction of the antigen. This is the primary immune response
What do b cell memory cells do
These cells do not produce antibodies but stay in the body for decades. When they are activated they rapidly produce plasma cells and more memory cells, this is the secondary immune response
What are the 5 steps of antibody action
-the antigen presenting cell
-activation of T and B cells
-action of T cells
-action of B cells
-antibody action
Describe the structure of an antibody
The 4 polypeptides have a constant region that is the same for all antibodies and a variable region that is specific to each antigen, this produces the antigen antibody complex
What does agglutination do
Causes a pathogens to stick together for phagocytes
What does complement activation do
Destroy plasma membrane the pathogen
What does toxic neutralisation do
Bind to toxins preventing them affecting cells
What does opsonisation do
Binding causes them to be consumed by phagocytes
What function does the antibody IgA have
Found in body secretions such as breast milks and saliva- prevents antigens crossing epithelial cells crossing into deeper tissues
What function does the antibody IgD have
Made by b cells and displayed on their surfaces. Antigens bind here which activates the b cell
What function does the IgE antibody have
Found on cell membranes and activate the inflammatory response
What function does the antibody IgG have
largest and most common- can cross placenta and attacks many pathogens
What function does the antibody IgM have
Produced in large amounts in the primary response - Activates the compliment system
Define immunity
The ability of the body to resist an infection by a pathogen
Define anti microbial resistance
Ability of a microorganism to survive exposure to antimicrobial agents such as antibiotics
What is antibiotic stewardship
The effort to measure and improve how antibiotics are prescribed by clinicians and used by patients
