Communicable Diseases part 2 Flashcards
What do the T-helper cells do?
the t-helper cells release cytokines
- these are chemical messengers which are involved in cell signalling
- also contains interleukins
- help stimulate phagocytosis
What do the interleukins do
the interleukins specifically bind to the naïve B-cells in order to stimulate their proliferation
- vary in shape and have to be complementary to the receptors in the B- cell in order to activate it
what do the T-killer cells do
they attack and kill the cells displaying foreign antigens,
produce cytoxins, perforin and granzymes
- the perforin has to be complementary in shape to the antigens displayed on the surface of the cell membrane
- the perforin then bind to the host cell receptors, this opens up pores in its membranes
- the granzymes then enter the cell and cause apoptosis
what do T-regulator cells do
they shut down the immune response after the last pathogen has been eradicated, this prevents autoimmunity
- if this did not happen the lymphocytes would keep attacking our tissues and our own antignes
What are the two types of B cells
plasma and B-memory cells
what do the plasma cells do
the plasma cells release antibodies which our specific to the pathogen,
the shape of the antibodies depends on which B-cell was originally selected these antibodies then bind to the antigens displayed on the pathogen membrane and brings the pathogen closer for phagocytosis, this prevents intracellular pathogens from entering the host cell
What do the T and B memory cell do?
after their production in the primary immune response they remain in the blood for many years, they act as immunological memory.
if they encounter the same type of antigen on a pathogen then they can quickly divide by mitosis
this happens quicker due to the increase in the presence of lymphocytes and increases their concentration
Whats a difference in the secondary immune response compared with the first immune response
don’t feel the symptoms in the secondary immune response
What do macrophages produces
they produce monokines these attract neutrophils and stimulate B cells to differentiate and release antibodies
What do many cells release
interferon this inhibits virus replication and stimulates the activity of the T killer cells
What releases interleukins
macrophages and T cells
What do interleukins do
stimulate the clonal expansion and differentiation of T and B cells
How is arteritis caused
is inflammation of the joints
- the antibodies attack the membrane around the joint
What happens in lupus
antibodies attack certain proteins in the nucleus and affected tissue
What are secondary defences
secondary defences are used to combat pathogens which have entered the body, they recognise the pathogens by there antigens on the cell membrane
What are ospins
protein molecules that are non-specific so they can attach to various antigens then bind to the phagocyte and pull it closer
what are the two types of phagocytes
neutrophil and macrophage
describe a neutrophil
multilobed nucleus manufactured in the bone marrow short lived released in large numbers during an infection engulf and digest pathogens
describe a macrophage
manufactured in bone marrow
travel in blood as monocytes before becoming macrophages in the lymph nodes
larger then neutrophils
round nucleus
describe the process of phagocytosis
an ospin, an antibody, is attached to the surface of a pathogen, they are non-specific in their shape so can bind to a range of pathogens
this brings the pathogen closer to the neutrophil so easier to engulf
the pathogen is enveloped by arms of the cell membrane caused pseudopia
the pseudopia from a circle around the pathogen called a vesticle
a vesticle plus a pathogen forms a phagosome
a lysome which is a sac of lytic enzymes fuse with the phagosome and release the lytic enzymes into the phagosome causing it to become digested and absorbed into the cytoplasm or ejected if toxic
after absorption it produces amino acids and sugar
this is called phagocytosis
How does a macrophage become an antigen presenting cells
macrophages engulf a pathogen but only partially digest the pathogen, the antigens from the cell membrane of the pathogens are saved and moved to a specialised protein complex on the surface of the cell
What is active immunity
Immunity caused by the stimulation of the immune response
What does the antigen presenting cell (APC) do
the APC moves around the body where it comes in to contact with specific cells that can initiate an immune response - t and B lymphocytes, only the T and B cells with correct shape so APC increases contact chance
What does the special protein complex do
this ensures the APC is not mistaken for a foreign cell and attacked by other phagocytes
