I Apinaya Amuthalingham I BTEC Applied Science I Biology I Unit 12 I Learning Aim D I How The
Human Body Responds To Diseases and Infections I
Non- Specific Defences:-
The defensive mechanism system in the human body provides immunity through a non-specific defense
system. It acts as a barrier to all antigens. This demonstrates that it is intrinsically immunological, and that
immune systems have physical barriers that prevent dangerous materials from entering the host's body; it
is a defensive immune response.
Non-specific physical defenses, such as skin, provide critical protection for bacteria in the body's
mechanism defenses, which include microbes. Considering the functions of the skin and mucous
membranes. Mechanical defenses are advantageous because they aid in the physical clearance of
microorganisms and residual detritus from contaminated or sick body surface regions. Because it can
damage and infect the mechanical defenses of the skin. Nasal hairs also function as a physical barrier
against infections. This is because the nose contains cells that may both create and capture infections
before they enter the lungs. When the host's nose is blown and the mucus is evacuated from the body,
pathogens become trapped inside it.
Chemical defenses in non-specific defenses are where lubricating gland secretion occurs. Sweat, a
chemical barrier of the skin, serves as an effective barrier against infections in the host's immune system.
Chemical secretions include stomach acid, hydrochloric acid, tears, and saliva, as well as the enzyme
lyzosome, which aids in the destruction of gram-positive bacteria by breaking down the peptidoglycan of
the cell, and mucus, a sticky substance secreted by tracheal goblet cells. They are also the chemical
barriers that aid in the release of lubricating glands in order to guard against and prevent future infections
or pathogens from entering the host's body.
Phagocytosis is the process by which pathogens are engulfed and destroyed by phagocytes. These cells
contain digestive enzymes in lysosomes, which contain and digest disease-causing microorganisms.
Important phagocytes include neutrophils and monocytes. This implies that the pathogens are engulfed
within a vacuole surrounded by the phagocyte's membrane. Enzymes are most commonly associated with
cells, and their function is to break down the pathogen in order to kill it. Phagocytosis is found in many other
cells and is necessary for tissue homeostasis.
Histamine and lysosomes are important components of the phagocytosis process. Histamine is an organic
substance that affects the body's immediate response in a variety of ways. It stimulates blood vessels
toward the vasodilite and increases capillary permeability. This is due to the fact that it increases blood flow
and allows phagocytes and other clotting elements to accumulate on the surface of the injury or infection.
Lysosomes are acidic and hydrolytic organelles that receive and digest their cargo. This implies that
lysosomes can degrade and terminate all types of biological polymers.
Specific Defences:-
1
, Immunity is the ability of the human body to develop resistance to specific pathogens, toxins, or other
foreign substances. This is referred to as the human body's distinct defense mechanism. This biological
mechanism can only occur when the immune system's special immune system produces antibodies or
activated lymphocytes that destroy specific organisms and toxins that try to infiltrate the immune system.
Specific defense is also known as adaptive immunity.
T lymphocytes or cells play an important role in the immune response to foreign substances. It plays an
important role in the adaptive immune system. T-lymphocytes kill infected host cells while also activating
immune cell responses. This is because T- lymphocytes produce cytokines to regulate the immune
system’s response. T-helper cells, T-killer (cytotoxic) cells, and T-memory cells are the three types of
immune cells. These immune cells have the ability to recognize soluble protein-based receptor antigens but
not soluble free antigens.
T- Helper Cells are immune cells that detect infections and activate cytotoxic T- cells, which produce
antibodies in the body; it is the most important adaptive immune response that can aid in the fight and
prevention of infections that infiltrate the immune system. T-killer (Cytotoxic) cells are another type of
immune cell that helps detect and destroy infected cells in the host's body that have transformed into
infectious viruses. T- Killer Cells destroy pathogen through a chemical process, T- Killer Cells bind with a
target cell and releases perforin, a load of toxic molecules, this then creates holes in the target cell and
causes itself to destruct. T-Memory Cells are antigen-exposed cells that can mediate a faster response
when the antigen is exposed again. T-Memory Cells have the ability to live and develop for an extended
period of time, implying that an infection can protect and prevent against other infections containing the
same pathogens.
B lymphocytes are white blood cells that produce antibodies. B- Lymphocytes are a part of the immune
system and are developed from within the bone marrow stem cells. Antibodies, also known as B Cells, bind
to and neutralize pathogens or foreign substances. There are two types of B lymphocytes: plasma cells and
memory cells. These two types of B-lymphocytes help with infection and disease prevention and treatment.
White blood cells produced by lymphoid organs are known as B-plasma cells. This is due to the fact that it
secretes more proteins, known as antibodies, in order to present itself to specific substances known as
antigens. Antibodies are immediately protected by B- Plasma Cells in particular. Their antibodies travel to
the antigen's site via blood plasma and the lymphatic system to neutralize or destroy it. This means that B-
Plasma Cells can protect the host's body from infection by producing antibodies that destroy infected
antigens.
B- Memory Cells are B- Lymphocytes that are produced by an adaptive immune system component. B-
Memory cells can be formed in the lymphoid organs' germinal centers. This is because B- Memory Cells
circulate in the bloodstream in a dormant state, where the cell is not in the cell cycle but can easily retain
and divide itself. Memory cells are responsible for remembering and recognizing antigen characteristics in
order to destroy or neutralize them with an antibody response. This suggests that B-Memory Cells infiltrate
unknown pathogens and provide long-term immune protection against infections.
Cell Mediated Response:-
2
Human Body Responds To Diseases and Infections I
Non- Specific Defences:-
The defensive mechanism system in the human body provides immunity through a non-specific defense
system. It acts as a barrier to all antigens. This demonstrates that it is intrinsically immunological, and that
immune systems have physical barriers that prevent dangerous materials from entering the host's body; it
is a defensive immune response.
Non-specific physical defenses, such as skin, provide critical protection for bacteria in the body's
mechanism defenses, which include microbes. Considering the functions of the skin and mucous
membranes. Mechanical defenses are advantageous because they aid in the physical clearance of
microorganisms and residual detritus from contaminated or sick body surface regions. Because it can
damage and infect the mechanical defenses of the skin. Nasal hairs also function as a physical barrier
against infections. This is because the nose contains cells that may both create and capture infections
before they enter the lungs. When the host's nose is blown and the mucus is evacuated from the body,
pathogens become trapped inside it.
Chemical defenses in non-specific defenses are where lubricating gland secretion occurs. Sweat, a
chemical barrier of the skin, serves as an effective barrier against infections in the host's immune system.
Chemical secretions include stomach acid, hydrochloric acid, tears, and saliva, as well as the enzyme
lyzosome, which aids in the destruction of gram-positive bacteria by breaking down the peptidoglycan of
the cell, and mucus, a sticky substance secreted by tracheal goblet cells. They are also the chemical
barriers that aid in the release of lubricating glands in order to guard against and prevent future infections
or pathogens from entering the host's body.
Phagocytosis is the process by which pathogens are engulfed and destroyed by phagocytes. These cells
contain digestive enzymes in lysosomes, which contain and digest disease-causing microorganisms.
Important phagocytes include neutrophils and monocytes. This implies that the pathogens are engulfed
within a vacuole surrounded by the phagocyte's membrane. Enzymes are most commonly associated with
cells, and their function is to break down the pathogen in order to kill it. Phagocytosis is found in many other
cells and is necessary for tissue homeostasis.
Histamine and lysosomes are important components of the phagocytosis process. Histamine is an organic
substance that affects the body's immediate response in a variety of ways. It stimulates blood vessels
toward the vasodilite and increases capillary permeability. This is due to the fact that it increases blood flow
and allows phagocytes and other clotting elements to accumulate on the surface of the injury or infection.
Lysosomes are acidic and hydrolytic organelles that receive and digest their cargo. This implies that
lysosomes can degrade and terminate all types of biological polymers.
Specific Defences:-
1
, Immunity is the ability of the human body to develop resistance to specific pathogens, toxins, or other
foreign substances. This is referred to as the human body's distinct defense mechanism. This biological
mechanism can only occur when the immune system's special immune system produces antibodies or
activated lymphocytes that destroy specific organisms and toxins that try to infiltrate the immune system.
Specific defense is also known as adaptive immunity.
T lymphocytes or cells play an important role in the immune response to foreign substances. It plays an
important role in the adaptive immune system. T-lymphocytes kill infected host cells while also activating
immune cell responses. This is because T- lymphocytes produce cytokines to regulate the immune
system’s response. T-helper cells, T-killer (cytotoxic) cells, and T-memory cells are the three types of
immune cells. These immune cells have the ability to recognize soluble protein-based receptor antigens but
not soluble free antigens.
T- Helper Cells are immune cells that detect infections and activate cytotoxic T- cells, which produce
antibodies in the body; it is the most important adaptive immune response that can aid in the fight and
prevention of infections that infiltrate the immune system. T-killer (Cytotoxic) cells are another type of
immune cell that helps detect and destroy infected cells in the host's body that have transformed into
infectious viruses. T- Killer Cells destroy pathogen through a chemical process, T- Killer Cells bind with a
target cell and releases perforin, a load of toxic molecules, this then creates holes in the target cell and
causes itself to destruct. T-Memory Cells are antigen-exposed cells that can mediate a faster response
when the antigen is exposed again. T-Memory Cells have the ability to live and develop for an extended
period of time, implying that an infection can protect and prevent against other infections containing the
same pathogens.
B lymphocytes are white blood cells that produce antibodies. B- Lymphocytes are a part of the immune
system and are developed from within the bone marrow stem cells. Antibodies, also known as B Cells, bind
to and neutralize pathogens or foreign substances. There are two types of B lymphocytes: plasma cells and
memory cells. These two types of B-lymphocytes help with infection and disease prevention and treatment.
White blood cells produced by lymphoid organs are known as B-plasma cells. This is due to the fact that it
secretes more proteins, known as antibodies, in order to present itself to specific substances known as
antigens. Antibodies are immediately protected by B- Plasma Cells in particular. Their antibodies travel to
the antigen's site via blood plasma and the lymphatic system to neutralize or destroy it. This means that B-
Plasma Cells can protect the host's body from infection by producing antibodies that destroy infected
antigens.
B- Memory Cells are B- Lymphocytes that are produced by an adaptive immune system component. B-
Memory cells can be formed in the lymphoid organs' germinal centers. This is because B- Memory Cells
circulate in the bloodstream in a dormant state, where the cell is not in the cell cycle but can easily retain
and divide itself. Memory cells are responsible for remembering and recognizing antigen characteristics in
order to destroy or neutralize them with an antibody response. This suggests that B-Memory Cells infiltrate
unknown pathogens and provide long-term immune protection against infections.
Cell Mediated Response:-
2
