Download Surname 1 Name Instructor Course Date Human Immune System

Surname 1
Name
Instructor
Course
Date
Human Immune System
The immune system is a body defense system that comprises of numerous biological
structures and many processes within an organism and protects the living organisms against any
disease. A well-functioning immune system must detect the variety of agents dubbed as
pathogens; they range from viruses to parasitic worms (Danilova 23). A perfect immune system
must also be able to distinguish between a pathogen and healthy tissues of the individual
organism.
The immune system can be grouped into subsystems, such as innate immune system against
the adaptive immune system or they can also be grouped into humoral immunity against cellmediated immunity. In human beings, the blood –brain barrier, blood-cerebrospinal fluid barrier,
and identical liquid brain barriers are separating the peripheral immune system away from the
neuroimmune system, which is protecting the brain.
There are well-structured components of the immune system ("Immune System" 195.) The
innate immune system has the following elements, the response is always non-specific, when
exposed it maximally respond, it has humoral and cell-mediated parts, It does not have
immunological memory, and it exists in almost all forms of life.
The adaptive section of the immune system has the following components. It has antigen
and pathogen-specific response, there is a lag time in between exposure and maximal response, it
Surname 2
has the humoral and cell-mediated components, and its exposure will always lead to
immunological memory. However, it is in vertebrates with jaws.
There is rapid evolution adaptation of pathogens to avoid detection and to neutralize the
immune system. Therefore, multiple defense techniques have also been developed by the
immune system to identify and dissolve the pathogens.
Adaptive immunity always create immunological memory immediately after there is the
initial response to some specific pathogen, this leads to stabilized and enhanced response in the
subsequent infections. This type of body protection is mostly acquired through immunization.
The immune system will always protect organisms from attack by infection with the second
layer defenses of increasing specificity. The immune system uses the physical barrier to prevent
viruses and bacteria from getting into the organism ("Immune System" 201.) Some pathogens
may be robust enough to overcome the obstacle hence it is the work of the innate immune system
to also provide an immediate, though nonspecific response.
If pathogens, also, evade the innate protective mechanisms, there is a second protective
layer possessed by vertebrates called the adaptive immune system, which is made active by the
natural response. At this level, the immune system is built during infection to always to able to
recognize the pathogens in the future infections. This boost in the immune system is retained
once the disease-causing organism has been eliminated. The immune system is called the
adaptive immunological memory. It strengthens with the increase in the number of times the
same pathogen attacks the body. It makes the innate immunity even stronger to counter attack
the future infections at faster rates.
Both the components of the immune system work on the principle of the ability to
distinguish between the self-molecules and the molecules of the pathogens. Immunology refers
Surname 3
to self-molecules as the components of the organism's body than are to be distinguished from the
infections causing organisms in the body. On the other hand, on self-molecules are the organisms
that are foreign into a particular body. They are called the antibody generators and are always
explained to be substances that combine to specific immune receptors hence causing an immune
response.
The innate system has the following protective mechanisms. The surface barriers. Skin
acts as a mechanical barrier to entry of pathogens. The body of the human being cannot be
entirely physical sealed against the disease causing organisms. Other systems are therefore
present to protect the body openings including lungs genitourinary tract and intestines. Lungs get
protection from factors like sneezing and coughing that mechanically remove pathogens and
other irritating substances from the respiratory system. The removal of urine and tears also
physically remove the pathogens. The mucus secreted by the breathing system together with the
gastrointestinal tract serves to pick and entangle the foreign organisms.
Inflammation also initiates natural protection. This is one of the initial responses to
immune system infection. Symptoms are swelling, heat and pain which are caused by the rise in
the blood flow in the tissues. This inflammation is always induced by the cytokines and the
eicosanoids, which are always released by the cells in the injury areas or points of infection.
Eicosanoids contain prostaglandins that always produce fever and always dilate the blood vessels
associated with inflation. Eicosanoids also have the leukotriene that attracts leukocytes.
Innate type of immunity also has a complement system called biochemical cascade,
which always attack the surfaces of the pathogens. It has over twenty different proteins, and its
name is derived from its ability to "complement" the killing of disease-causing organisms by use
of antibodies and is the primary humoral composition of the innate immune system.
Surname 4
In the human system, activation of the response occurs when the complement binds to
the antibody attacking this microbial or also the complement protein can bind to the surface of
the carbohydrates of surfaces of the microorganisms. Once a microbe is detected, a signal is sent
hence triggering multiple killing responses. They then produce peptides, which end up attracting
immune cells that will finally destroy the pathogen. Complement can still kill cells by directly
causing disruption to their plasma membrane.
The adaptive immune system also works through a complex of the system as follows.
The adaptive immune system has leukocytes, which have; Lymphocytes, T cells and B cells that
are the main types of lymphocytes and they come from hematopoietic stem cells found in the
bone marrow cells take part in cell-mediated immune response while B cells involved in the
humoral immune response. Both of B cells and T cells have receptor molecules that always
recognize specific targets.
The adaptive immune system also has the Killer T cells. This is a sub-group of T cells,
which are infected with some pathogens, or damaged. The T killer cells activate their receptors
bind with specific antigen. The other forms of adaptive protection involve T helper cells, Gamma
delta T cells, and Alternative adaptive immune system.
Disorders of the immune system make the immune system not to work generally.
These disorders are categorized into immunodeficiency, hypersensitivities, and the autoimmunity
hence bringing problems to the general function of the immune system. Immunodeficiency
occurs when a part or all the components of the immune system are not active it hence
diminishes the ability of the immune system to fight pathogens. It is so familiar to young people
and the aged whose immune systems are so weak or declining with time due to
Surname 5
immunosenescence at old age. It is also caused by malnutrition. The body cannot hence fight
pathogens effectively.
Another disorder is autoimmunity. Immune system fails to function properly. It cannot
distinguish between self and non-self molecules. It hence attacks part of the body.
The last disorder is the hypersensitivity. It occurs when the immune system damages
the own body's tissues. The allergy causes type 1 hypersensitivity. Symptoms can be mild
discomfort or may even lead to death. Type ii occurs when the antibodies bind to antigens on the
owner's body cells resulting in a destruction of the cells.
All the above disorders hinder the practical function of the immune system to fight
pathogens.
Surname 6
Work Cited
Beck G, Habitat GS (November 1996). "Immunity and the Invertebrates" (PDF). Scientific
American. 275 (5): 60–66. doi: 10.1038/scientificamerican1196-60. Retrieved 1 January 2007.
Danilova, Nadia. "Evolution of the Human Immune System." eLS, 2013.
"The Immune System." Human Blood Plasma Proteins, pp. 195-229.