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Unit 12 Part D - Body defence
- Institution
- PEARSON (PEARSON)
This assignment got me a Distinction. It is very detailed. Include diagrams drawn by me. A lot of work with many pictures and everything is explained in my own words.
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The immune systemOrgans, cells, and a variety of substances will work together to combat microorganisms. The immune
system's essential components are WBC, antibodies, the complement system, the lymphatic system,
the thymus, spleen, and bone marrow. Nonspecific innate immunity and specific acquired immunity are
two joint defence systems that provide disease immunity. Nonspecific defence mechanisms reject all
pathogens equally, while specific immune responses are tailored to specific kinds of invaders. Both
systems work hard to maintain pathogens from entering the body and multiplying.
Describe the components of the specific and non-specific defence mechanisms in protecting the body.
Two types of the immune system:
1) NON-SPECIFIC MECHANISMS
Innate immunity
The non-specific defensive mechanism that will fight immediately within an hour of an antigen’s
presence in the human body refers to innate immunity.
Physical barriers are for example skin, chemicals found in the circulation and the immune system that
will target unknown cells in the human body that are examples of these systems.
Non-specific defence mechanisms and physical barriers
Physical barriers have a key role in blocking any unknown pathogens from any tissue that allows for
infection. One of the most important physical barriers is the skin which could be composed of the three
layers.
The mucous membranes and skin are included. They remove impurities from membrane surfaces while
also acting as a physical barrier against pathogens. Viruses, bacteria, and other pathogens are
prevented from entering the body's blood tissue by the thick layers. Skin functions to shield us from
the 8nhternat elements to which we are exposed.
Two examples are mucous pushing substances toward the digestive tract and tears cleaning
substances from the eyes. The stomach contains hydrochloric acid, which lowers the pH so that
pathogen enzymes are denatured and all organisms are killed.
Phagocytosis is a cellular process that involves the ingestion and removal of particles with a diameter
greater than 0.5 microns, such as bacteria, foreign substances, and apoptotic cells. Phagocytosis
occurs in a wide range of cells and is hence an important cellular homeostatic mechanism.
COMPONENT FUNCTION
Line the respiratory tract and help to retain
CILIA inhaled debris in the throat, enabling it to exit
the body more rapidly.
DEFECATION Help to excrete microorganisms via
defecation/stool and vomit
HAIR Bacteria, pollution from air, and dust can be
, filtered out of the nose, preventing microbes
from entering the body and invading.
MUCOUS MEMBRANE Produce mucus to capture microorganisms and
prevent them from spreading throughout the
human body.
SKIN The skin provide a physical barrier for pathogens
such as bacteria microbes.
2) Adaptive immunity: Antigen-specific immune response that is referred to the adaptive
immunity. Moreover, the adaptive immune response is overly complicated than the innate
response The adaptive immune response acts as the body's protection mechanism against non-
self-pathogens.
Only invertebrate vertebrates have adaptive immunity, also known as acquired immunity or
specific immunity. Pathogen-specific adaptive immune responses exist. The adaptive immune
response is designed to combat non-self-infections, but it could also be used to hurt oneself. As
a result, autoimmune disorders such as lupus and rheumatoid arthritis might develop. Pre
triggered reactions are a set of nonspecific illness mechanisms seen in the body. The acute-
phase response and the inflammatory response are two of them, and both can both eradicate
infection or postpone it until specific, acquired immune responses kick in. The ability to
differentiate between distinct substances, known as specificity, and the ability to respond more
vigorously to repeated exposures to the same microorganism, known as memory, are the
fundamental characteristics of adaptive immunity. Lymphocytes and their produced products,
such as antibodies, are the distinctive features of adaptive immunity. Antigens are foreign
substances that activate specific immune responses or are recognised by lymphocytes or
antibodies.
A distinctive immune system produces antibodies and/or enabled lymphocytes that combat and
destroy specified invading pathogens or toxins, attempting to make this achievable.
Specific defence can be classified into two parts. Cell-mediated immunity and antibody-mediated
immunity are two such examples. T-lymphocytes (T-cells) are stimulated by pathogens, culminating in
cell-mediated immunity. T-cells that were activated attack pathogens directly.
When T-cells were exposed to pathogen antigens, cells become active. T-cells respond to antigenic
determinants, which are parts of antigens (epitopes). T-cells possess antigens receptors on their
surface that engage with pathogen antigenic determinants. Polypeptide chains having variable or
consistent sections try to compensate antigen receptors. The antigenic determinant interacts with the
variable region. This is known as direct T-cell activation. Antigen-specific responses are highly adapted
to the pathogen and tightly regulated by interaction among innate immunity in adaptive immunity. It
has evolved a diverse and tuned range of receptors that really can differentiate between self-and-self-
antigens.
COMPONENTS FUNCTIONS
LYSOZYME Lysozymes are a type of enzyme found in
tears, saliva, and sweat that can break down
cell walls and kill bacteria by acting as an
antibiotic.
Gastric juice Acids found in the stomach which can destroy
toxin and bacteria
Hyaluronic acid A gelatinous material that prevents the
spread of harmful germs in the body.
Hydrochloric acid Viruses and bacteria present in the stomach
are eliminated, and the body is protected
against infections.
Compare the specific and non-specific defence mechanisms in terms speed of elimination from the
body of the pathogen.
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