Essay
unit 12d: non specific/specific immune responses
- Institution
- PEARSON (PEARSON)
Essay of 9 pages for the course Unit 12 - Diseases and Infections at PEARSON (distinction 12d)
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(NON-SPECIFIC IMMUNE RESPONSE) PHYSICAL BARRIER- LysosomesT cells are
PHYSICAL a type of
BARRIER- white blood cell
Skin Killer T cells play Lysosomes are in
a critical role organelles
the found in animal cells. When a pathogen enters a
cell, lysosomes can fuse with the membrane that surrounds the pathogen,
that play a critical role in the immune response. They are able to
The skin acts as a physical barrier that prevents pathogens releasing their digestive enzymes into the surrounding area. These
immune response. They are an recognise and bind to cells that have
from entering the body. The outermost layer, known as the enzymes can then break down the pathogen, rendering it harmless. This
essential ispart
epidermis, of the body’s
composed of deaddefences been
skin cells that are richinfected
in by process
a pathogen and Memory T cells form during an initial
is known as lysosomal destruction.
againstcalled
protein infection and
keratin. disease
This and are
layer helps to prevent then
water release
loss toxic substances that immune response to a pathogen. After
able
and to recognise
protects and respond
the underlying to a skin damage.
layers from can damageTears or kill Lysosomes
the infectedcontain
cells.a variety of digestive enzymes including, proteases,
the infection has been cleared, some of
wide
are range from
produced of pathogens.
the lachrymal glands. Tears help This to lipases,
process helps to prevent the and nucleases. These enzymes are capable of breaking down a
the T cells that were activated during
protect the eyes by flushing out irritants and pathogens, wide range of biomolecules including proteins, lipids, and nucleic acids.
spread of infection and promote the response
T cells
and are produced
by providing in the
a physical bone
barrier against infection. Also, Killer T When a pathogen enters a cell, lysosomes remaincan fusein thethe
with body as
membrane
recovery. cells are able to memory
marrow
the and then
skin contains mature cells
Langerhans in thewhich can recognise andinfected surrounding the pathogen and releaseT their
cells.enzymes
These cells remain
to break down in and
recognise cells by detecting the lymph nodes and are
destroy the pathogen. This process is known as phagocytosis. By breaking able to
thymus,towhere
respond pathogenstheythat
undergo
enter thea body through the skin.
specific proteins (antigens) on the pathogens,
down and digesting ‘”remember”
lysosomes the helppathogen,
prevent theand if the
spread of
process
These cellsofcan
selection
activate and education
the immune system and help
surface of the cells. Once they have
infections and protect the body bodyfrom is later
harm. on exposed to the same
neutralise
that helps pathogens
to ensure before
that they
theycanarecause harm.
identified an infected cell, they can pathogen, the memory T cells are able
able to recognise and respond to
The dermis contains hair follicles, sweat glands release and toxic substances, such as to respond more quickly than the first
pathogens
sebaceous whilewhich
glands, avoiding
produceattacking
sweat and oilperforin
(sebum) and CHEMICAL BARRIER- Hydrochloric acid
to granzymes, that can time around. This faster response is due
the regulate
help body’s own cells.temperature and keep the skin
the body damage or kill theHydrochloric
cell. acid, which isto produced
a number in the
of stomach, plays an important
factors, including
moisturised. Sweat contains antimicrobial peptides which role in protecting the bodyincreased from pathogens by creating an acidic more
Once they have matured, T cells are sensitivity to pathogen,
can help kill bacteria and viruses, while sebum contains environment that can kill many
ableacids
fatty to circulate
that can throughout
prevent the growth the of bacteria on the rapid activation, and increased When food
types of bacteria and viruses.
body and respond to infection by Helper T cells are able
enters to
the recognise
stomach, cells in the stomach lining release hydrochloric acid
skin. production of cytokines.
releasing chemicals that help to and bind to antigens on the
to lower the surface
pH of the stomach contents. The low pH makes it difficult
activate other immune cells and of infected cells, which helps to to survive and can help prevent infections from food
for bacteria/viruses
PHYSICAL BARRIER- Mucus/Cilia activate the immune bornesystem
pathogens.
and In addition,Regulatory
hydrochloric acid can also activate
destroy infected cells. T cells help to suppress
enzymes that help break down proteins in food, making them easier to
Mucus and cilia are part of the body’s non-specific promote
immunethe destruction of infected the immune response and prevent it
digest.
system, which provides defence against pathogens. cells. Onceisthey
Mucus a have recognised an from attacking healthy cells and
sticky substance
Humoral produced
immunity by cells
involves antigen,
thein the respiratory and helper t CHEMICAL
cells can release
BARRIER- Phagocytosis tissues. By suppressing the immune
digestive
productiontractsofthat helps trap
antibodies bypathogens
B cells. B and other foreign known as cytokines, that
chemicals, response to these self-antigens,
particles.
cells areCilia are tinyin
produced hair-like
the bone structures that line help theto activate other Phagocytosis
immune is the
cells,process by which certain immune cells can engulf and
regulatory T cells help to prevent
respiratory tract and move in coordinated wavessuch to helpas move
B cells and destroy
killer pathogens.
T cells. Phagocytes are immune cells that specialise in
marrow and circulate in the blood autoimmune
and engulf adiseases,
mucus and trapped particles out the body. Together, mucus phagocytosis and can recognise wide range in of
which the
pathogens,
and lymphatic system. B cells help These cells then work together to immune system mistakenly attacks
and cilia form a powerful defence against respiratory including bacteria, viruses and fungi.
protect the body by producing destroy the infected cells and healthy cells and tissues. Regulatory
infections. When a pathogen enters the respiratory tract,
antibodies, which are proteins that
mucus and cilia work together to trap and remove pathogens. prevent the spreadTheofprocess
infection.
of phagocytosis begins T cellswhenare alsoa phagocyte recognisesthe
able to suppress a
pathogen. The phagocyte can do this by detecting specific molecules on
canmucus
The recognise
traps and which prevents itHelper
bind to specific
the pathogen from T cells are also able to immune response to other antigens,
antigens, promote the surface
the production of of the pathogen that are not present on the surface of healthy
entering thesuch
lungs,asand
those
thefrom
cilia pushes the mucus and such as those from pathogens,
cells. Once it recognises the pathogen, it extends its cell membrane
pathogens.
pathogen intoWhen a B cell
the throat where it can be coughed antibodies,
up and which can help to which
around the pathogen and engulfs it. can
The help to prevent
pathogen excessive
is then contained
expelled from an
encounters theantigen,
body .In itsaddition to trapping and
activated removing
neutralise pathogens and prevent inflammation and tissue damage.
within a membrane-bound vesicle called a phagosome, where the
pathogens,
and beginsmucus also contains
to produce large antibodies and other futureimmuneinfections.phagocyte can destroy it. The phagosome fuses with lysosomes which
molecules
amountsthat can help neutralise
of antibodies that arepathogens and prevent break down the pathogen into small pieces, which can then be presented
infections. 1.When a pathogentoenters the body, it is
specific to that antigen. These other immune cells as recognised
antigens. This byprocess
immune cells
helps calledthe
activate antigen-
antibodies can then bind to the presenting cells, which engulf the pathogen and break it down into
adaptive immune system and can help prevent future infections by the antigens.
CHEMICAL BARRIER- Histamine
pathogen and help neutralise it, 2.The antigens are displayed
same on the surface of the APCs, where they can be recognised
pathogen.
Histamine
making itiseasier
a chemical released by the by
that isimmune
for other B cells.
immune When a B cell encounters an antigen that matches its specific receptor, it is
system
cells in response to an injury or infection. It helps to
activated increaseand dividesCHEMICAL
rapidly. BARRIER- Lysozymes
cells to destroy it. B cells can also for
blood flow to the affected area, which brings white 3.Theblood cells B cells differentiate into plasma cells, which produce large amounts of
activated
memory cells, which are able to lysozymes are enzymes that help protect the body from bacterial
and nutrients to help fight off the infection. Histamine antibodies can that are specific to the antigen. Each antibody consists of two heavy chains
remember the antigen and respond infections. They work by breaking down the cell walls of bacteria, which
also cause inflammation, which can lead to redness, swelling,
more quickly and effectively to and two light chains andhelp
can hastoa kill
binding site that
the bacteria andisprevent
complimentary to the
the infection fromantigen.
spreading.
and pain.
future infections caused by the same 4.The antibodies areThey released into in
are found the bloodstream
tears, mucus, andand other fluids of the body,
saliva.
pathogen. where they can bind to the pathogen.
5.Some of the activated B cells differentiate into memory cells.
, (SPECIFIC IMMUNE RESPONSE)
Comparison of specific and non-specific
Non-specific defence mechanisms are the first line of defence against pathogens, and they are
present from birth. They include physical barriers like skin and mucus membranes, as well as
chemical barriers like stomach acid and enzymes in tears. These mechanisms are not specific to any
particular pathogen, meaning they can provide protection against a wide range of pathogens.
However, they are not always effective against specific pathogens, and they do not provide long term
immunity. Non-specific defence mechanisms act quickly to prevent pathogens from entering the
body, but they do not target specific pathogens.
On the other hand, specific defence mechanisms are part of the adaptive immune system, which is
activated when non-specific mechanisms are breached. These mechanisms are highly specific to
particular pathogens, and they can provide long term immunity. Specific defence mechanisms
include humoral immunity (mediated by B cells and antibodies) and cell mediated immunity
(mediated by T cells). These mechanisms are slower to respond to infection than non-specific
mechanisms, as it takes time for B and T cells to be activated and to produce antibodies. However,
once activated, specific defence mechanisms are highly effective at targeting and eliminating the
specific pathogen that triggered the immune response.
Both specific and non-specific defence mechanisms are important components of the immune
system, and they work together to protect the body against pathogens. However, there are some key
differences between the two types of defence mechanisms.
Both specific and non-specific defence mechanisms are essential for protecting the body against
pathogens. Non-specific mechanisms are the first line of defence and provide immediate protection
against a wide range of pathogens. They are not specific to any particular pathogen and include
physical barriers like the skin and mucus membranes, as well as stomach acid and enzymes in saliva
and tears. Non-specific defence mechanisms also include immune cells like neutrophils and
macrophages, which engulf and destroy pathogens, and natural killer cells which attack infected
cells. Specific defence mechanisms also include immune cells such as B cells and helper T cells. Both
mechanisms also rely on chemical signals such as cytokines to coordinate the immune response.
Additionally, both types of defence mechanisms can involve the use of phagocytic cells to engulf and
destroy pathogens.
While specific and non-specific defence mechanisms both play important roles in protecting the body
against pathogens, there are some key differences between the two. Non-specific defence
mechanisms are present from birth and provide immediate protection against a wide range of
pathogens, while specific defence mechanisms are activated only when non-specific mechanisms are
breached. Non-specific defence mechanisms are not specific to any particular pathogen, while
specific defence mechanisms are highly specific to particular pathogens. Non- specific defence
mechanisms do not provide long-term immunity, while specific defence mechanisms can provide
long term immunity. Non-specific defence mechanisms act quickly to prevent pathogens from
entering the body, while specific defence mechanisms are slower to respond to infection but are
more effective at eliminating specific pathogens.
Overall, specific, and non-specific defence mechanisms are both essential for protecting the body
against pathogens. While non-specific defence mechanisms provide immediate protection against a
wide range of pathogens, specific defence mechanisms are highly specific to particular pathogens
and are more effective at eliminating them. Both types of defence mechanisms involve the activation
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