cell types and adaptive immunity Flashcards
(30 cards)
What are the four major characteristics of adaptive immunity?
Diversity of lymphocytes and receptors, self-tolerance, proliferation after activation, and immunological memory.
Where do T and B cells mature?
T: In the thymus gland.
B: In the bone marrow.
How many antigen-binding sites do a T and B cell receptor have?
T: One.
B: Two.
Where do both B and T cells originate?
In the bone marrow.
What do antigen receptors do?
Recognize and bind to specific antigens.
Are all antigen receptors on a single B or T cell identical?
yes
What is self-tolerance in the immune system?
The ability of immune cells to avoid attacking the body’s own cells.
What happens to lymphocytes with self-reactive receptors?
They are eliminated or inactivated during maturation.
What is clonal selection?
The process where an antigen binds to a specific lymphocyte, which then proliferates and differentiates.
What do lymphocytes become after clonal selection?
Effector cells and memory cells.
What is the function of memory cells?
Long-lived cells that trigger a faster response upon re-exposure to the same antigen.
What is the function of effector cells?
Short-lived cells that actively combat pathogens immediately.
What are plasma cells?
Effector B cells that secrete antibodies.
What are the two main types of effector T cells?
Helper T cells and cytotoxic T cells.
What is immunological memory?
The long-term ability to respond more effectively to previously encountered antigens.
What is the primary immune response?
The initial response to a new antigen, peaking 10–17 days after exposure.
What is the secondary immune response?
A faster, stronger, and longer-lasting response to a previously encountered antigen.
What is the humoral immune response?
B cells and antibodies neutralize pathogens in blood and lymph.
What is the cell-mediated immune response?
Cytotoxic T cells destroy infected or abnormal cells.
What do helper T cells do?
Activate both humoral and cell-mediated immune responses.
What is an epitope?
The specific part of an antigen recognized by an antibody.
What are three functions of antibodies?
1) Block viruses from binding to host cells
2) Promote phagocytosis
3) Activate the complement system
How does the complement system destroy pathogens?
By forming a membrane attack complex that lyses the foreign cell.
What do cytotoxic T cells do?
Kill infected, cancerous, or foreign cells using toxic proteins.
