chapter 12- communicable DISEASES Flashcards
what are the two types of lymphocytes
b and t lymphocytes
where are b and t lymphocytes both produced
in the bone marrow
where do b lymphocytes mature
in the bone marrow
where do t lymphocytes mature
in the thymus
what is a naive b lymphocyte
one that has never encountered the pathogen it has complementary receptors /is specific to
what stimulates the clonal expansion of b cells
interleukins
many of the cloned b cells differentiate into what
plasma cells that secrete the same antibody
what do antibodies in the blood do
circulate in the blood and lymph where they bind to the foreign antigens at the site of invasion
not all of the clones differentiate into plasma cells some….
remain as memory cells within the lymphatic system
what is antigen presentation
when the macrophage presents the foreign antigens on their surface membrane to the b lymphocytes in the lymph nodes
what is an immune response
the process of destroying a non self cell
what is a self cell
one that is from the body
what is a non self cell
a foreign cell
what is a pathogen
any microorganism that causes disease
what is a lymphocyte
a type of white blood cell that identifies non self cells
what is an antigen
a protein in the cell surface membrane that triggers an immune response
how are lymphocytes able to recognise antigens
they have receptors that are complementary to antigens on non self cells
each lymphocyte has receptors that can recognise
one specific anigen
the shape of rhe antigen binding site is a result of its…
tertiary structure
four examples of passive physical barriers which help plants prevent the entry of pathogens
bark, waxy cuticles, closing stomata, cellulose in cell walls
How is a plant’s response to attack by pathogens triggered?
By cell signalling involving the release of signalling molecules. This is triggered by molecules associated with cell damage or pathogen entry attaching to receptors.
Name two materials actively produced by plants in response to infection.
Callose and lignin.
Where is callose deposited to help prevent the spread of a pathogen in a plant? (3 things)
Where is callose deposited to help prevent the spread of a pathogen in a plant?
Give five types of defence chemicals in plants.
Give five types of defence chemicals in plants.
Name two barrier defences which help prevent entry of pathogens in animals
skin and mucous membranes
Name three defence mechanisms, other than barrier defences, which help prevent entry of pathogens in animals.
blood clotting, wound repair, expulsive reflexes
Name two chemical secretions which help prevent entry of pathogens in animals
lysozymes and stomach (HCl) acid
In the inflammatory response, which two chemicals are released by mast cells?
cytokines and histamines
What are the effects of histamine on tissues?
dilation of blood vessels causing heat, redness and increased formation of tissue fluid causing swelling (oedema)
Name two non-specific defence mechanisms which act in response to the entry of pathogens in animals.
fever, phagocytosis