1. Attraction - The pathogen is
detected by the phagocyte,
causing the phagocyte to
move towards it.
2. Engulfing - Pathogen
attaches to receptors on
outside of phagocyte, causing
the phagocyte to engulf it in a
process called endocytosis.
3. Phagosome - A
phagosome is
formed when the
pathogen is
engulfed
4. Phagolysosome -
Lysosomes bind
with the
phagosome, forming
a phagolysosome
5. Digestion and absorption - The
lysosomes that bind with the
phagosome contain digestive
enzymes which break down the
pathogen. Any useful components
gathered from the breakdown of
the pathogen are absorbed.
6.Discharging waste -
Any products that
cannot be digested
are discharged
Cell-mediated response
The cell mediated response
requires T lymphocytes
These are produced in the
bone marrow and mature in
the thymus gland, making
them "T" cells
1. When the phagocyte ingests
the pathogen it presents its
antibodies on its surface.
2. Complementary
receptors on a T-helper
cell bind with the
presented antigen
3. The T-helper cell then becomes
activated and divides rapidly by
mitosis. This is called clonal
selection and is part of the primary
immune response.
4. The cloned
T-helper cells
can go on to...
Produce memory cells for
when the body
encounters the pathogen
again
Activate Killer T cells
which will destroy the
pathogen
Activate the humoral response
Immunity
Primary and
secondary
immune response
The primary immune response is when the
body encounters a pathogen for the first time
and sets up immunity by creating memory
cells which remember the pathogen if it is
encountered again.
The initial encounter
produces a relatively
low amount of
antibodies
There is a lag phase
after the first exposure
where the pathogen is
engulfed, its antigens
presented, a T-helper
cell attached and clonal
selection activated