RESPONSE TO INFECTION Flashcards
SPECIFIC (21 cards)
What is a specific immune response? (1)
are triggered by, and directed towards specific pathogens
what are lymphocytes? (1)
a group of leucocytes
what are the types of lymphocytes? (2)
- B lymphocytes (B cells)
- T lymphocytes (T cells)
what is the function of B cells? (1)
secrete antibodies (producing the humoral immune response)
What is the function of T cells? (1)
attack infected cells (producing the cell-mediated immune response) and assist B cells
what are T and B cells produced by? 91)
produced by multipotent stem cells in the marrow of certain bones. The lymphocytes then migrate to different locations where they undergo seperate maturation processes
where do T cells mature? (1)
T cells leave the bone marrow and complete their maturation in the thymus gland
where do B cells mature? (1)
B cells do not leave the bone marrow, but complete their maturation within the bone marrow.
What occurs during the maturation of both T and B cells? (1)
during their maturation, any lymphocytes that would react against the bodies own cells are selectively destroyed.
What happens after maturation of both T and B cells? (1)
Mature B and T cells re-join the blood system, many are stored in lymph nodes throughout the body.
what glycoproteins identify cells? (1)
they ae known as major histocompatibility complex (MHC) proteins
what are MHC proteins called in humans? (1)
human leucocyte antigens (HLA)
what is the function of the HLA proteins? (1)
these proteins are encoded by genes on the short arm of your chromosome and are genetically determined so determine the features you inherit. they show a lot of variation in the proteins they encode.
What makes T and B cells unique in the ways they respond to antigens? (1)
both lymphocytes have receptors on their cell surface membrane which are complementary to antigens (they only have one type on each cell)
what are the most common antibodies, in terms of proteins? (1)
both are a type of protein called an immunoglobulin.
what are the two most common antibodies? (1)
IgG and IgM
what is the structure of the antibody IgG? (2)
the smaller of the two, had 4 polypeptides linked by disulphide bridges to form a Y-shape and that 2 of these polypeptides are large (the heavy chains) while two are small (the light chains). Only two parts of the antibody molecule bind o a complementary antigen.
what is the structure of the antibody IgM? (2)
the larger of the two, formed by 5 IgG - like molecules held together.
what are the antigen-receptor molecules on the surface of T cells similar to? (1)
they are chemically similar to the Y-shaped IgG immunoglobin but only have two polypeptide chains instead of 4.
how do the antibody molecules on the surface of T and B cells differ? (1)
Each T cell has only one type on its surface. Unlike B cells, T cells do not release their antigen-receptor molecules.
When are antigen-receptor molecules that attack your own MHC proteins destroyed? (1)
during the maturation of both T and B cells, Type 1 diabetes is an example where this is not the case.
