Immune system overview Flashcards
Central (primary) lymphoid organs:
provide the microenvironment for maturation of B and T cells
Haematopoietic stem cells are pluripotent, which means they are:
capable of developing into any blood cells
Lymphocytes continually recirculate through peripheral lymphoid tissue in order to:
efficiently encounter antigen
Peripheral lymphoid organs:
are designed to maximize the contact between antigen and lymphocytes
The primary purpose of adaptive immune system is to:
protect from disease upon reinfection with a specific pathogen
Rapid but non-antigen specific immune response are produced by the:
Innate immune system
Vaccination protects us from inceftious by generating memory:
lymphocytes
Which situation describes an example of innate immunity?
Antigen removal by cilia in the respiratory tract
The antigen specificity of an adaptive immune response is due to:
activation of antigen-specific lymphocytes
Clonal selection results in:
proliferation of antigen-specific lymphocytes
Cytokines are NOT:
antigen-specific
A fundamental difference in the antigen receptors of B and T cells is:
different requirements for antigen presentation
Genes for immunoglobulins (antibodies) are unlike other human genes in that:
gene segments must be spliced together to make each unique antibody molecule
Humoral immunity can be acquired passively by:
recieving serum from someone who has recovered from an infection
Inflammation does NOT involve:
secretion of antibodies
Innate immune responses are most effective against:
common antigens on bacteria
Lymphocytes acquire their antigen specificity:
before they encounter antigen
A secondary immune response is NOT:
preceded by a longer lag period than a primary response
Antibody effector functions include all of the following:
- activating complement on bacterial surfaces to promote phagocytosis by neutrophils
- binding extracellular viruses to block their entry into host cells
- blocking uptake of bacterial toxins by host cells
- coating bacteria to promote their phagocytosis by neutrophils
Effector functions of complement include:
- attracting phagocytes to the sites of inflammation
- facilitating phagocytosis of complement-coated bacteria
- increasing blood vessel permeability to plasma proteins
- lysing bacterial cells
Jenner observed that milkmaids who were infected with cowpox were later immune to smallpox infections, this is an example of:
memory response to a cross reactive antigen
Macrophages generally kill the bacteria they phagocytose by fusing lysosomes containing digestive enzymes with the phagocytic vesicle. In the case of pathogens which block this fusion, pathogen killing can still be achieved through the effector function of:
Th1 cells
Phagocytosis can be:
stimulated by antigen binding to complement or antibody
Several friends who went on a picnic together developed vomiting and diarrhoea from
eating potato salad contaminated with St. aureus enterotoxin. Effects of the toxin
could best be counteracted by:
antibody binding and neutralizing the toxin
These statements are true:
- an example of passive humoral immunity is treatment with horse anti-snake venom
- antigen recognized by helper T cells must be associated with Class II MHC molecules on the surface of professional APC
- each lymphocyte has many antigen binding receptor, each receptor capabler of binding the same antigen
- recognition and killing of virus infected cells by cytotoxic T cells is an example of adaptive immunity
