What type of immunity is mediated by antibodies circulating in the blood?
Humoral Immunity
Humoral immunity is B-cell mediated.
What type of immunity is T-cell mediated?
Cellular Immunity
Cellular immunity involves T-cells.
Which cells are involved in recognizing free antigens?
B cells
T cells cannot recognize free antigens.
Where do B cells mature?
Bone marrow
B cells originate from the bone marrow.
Where do T cells mature?
Thymus
T cells originate from the bone marrow but mature in the thymus.
What is the relationship between specificity and the adaptive immune system?
Antibodies/B-cells and T-cells function only against the specific antigen they were produced in response to
This specificity is crucial for targeted immune responses.
What is memory in the context of the adaptive immune system?
Lymphocytes are programmed to recall their first encounter with an antigen and respond rapidly to subsequent encounters
This is known as an anamnestic or secondary response.
What do helper T-cells secrete?
Cytokines, like Interleukins
Helper T-cells play a crucial role in regulating immune responses.
What is the function of cytotoxic T cells?
Lyses target cells or induces apoptosis by releasing perforin and granzymes
Cytotoxic T cells are essential for killing infected or cancerous cells.
What are NK cells?
Murderous lymphocytes that do NOT have antigen-specific surface receptors
NK cells kill target cells in the absence of MHC-I.
What is the role of NK cells in Antibody-Dependent Cell Mediated Cytotoxicity (ADCC)?
Lyses antibody-coated cells
This includes protozoans and helminths.
What is naturally acquired active immunity?
Resulting from infection
This type of immunity develops after exposure to a pathogen.
What is naturally acquired passive immunity?
Maternal antibodies passed through transplacental transmission or colostrum
This provides temporary immunity to the infant.
What is artificially acquired active immunity?
Injection of antigen (vaccination)
This stimulates the immune system to produce its own antibodies.
What is artificially acquired passive immunity?
Injection of an antibody or selected immune substance
This provides immediate, but temporary, protection.
