Disease and the Disease and the Immune SystemImmune System

Disease: Any change to Disease: Any change to normal body function normal body function except for injury.except for injury.

Some diseases are geneticSome diseases are genetic PKUPKU Sickle-cell anemiaSickle-cell anemia Type I DiabetesType I Diabetes __________________________________________________

Materials in the environment often cause Materials in the environment often cause disease.disease.

Cigarette smokeCigarette smoke ChemicalsChemicals ToxinsToxins __________________________________________________

Some diseases are geneticSome diseases are genetic PKUPKU Sickle-cell anemiaSickle-cell anemia Type I DiabetesType I Diabetes __________________________________________________

Materials in the environment often cause Materials in the environment often cause disease.disease.

Cigarette smokeCigarette smoke ChemicalsChemicals ToxinsToxins __________________________________________________

Other causes of diseaseOther causes of disease

Pathogens: The causes of infectious diseases.Pathogens: The causes of infectious diseases. Bacteria, virus, protozoa, fungi, and parasitesBacteria, virus, protozoa, fungi, and parasites Not ALL species of these organisms are pathogens. Not ALL species of these organisms are pathogens.

Reservoir: Source of the pathogen in the Reservoir: Source of the pathogen in the environment.environment. Animals, humans, soil, inanimate objects.Animals, humans, soil, inanimate objects.

Infectious Infectious disease___________________________________disease__________________________________________________________________________________________________________________________._____.

Pathogens: The causes of infectious diseases.Pathogens: The causes of infectious diseases. Bacteria, virus, protozoa, fungi, and parasitesBacteria, virus, protozoa, fungi, and parasites Not ALL species of these organisms are pathogens. Not ALL species of these organisms are pathogens.

Reservoir: Source of the pathogen in the Reservoir: Source of the pathogen in the environment.environment. Animals, humans, soil, inanimate objects.Animals, humans, soil, inanimate objects.

Infectious Infectious disease___________________________________disease__________________________________________________________________________________________________________________________._____.

Spread of infectious Spread of infectious diseasesdiseases

Physical contactPhysical contact Touch, sexual or indirect contactTouch, sexual or indirect contact

Contaminated food/waterContaminated food/water Infected animalsInfected animals VectorsVectors

Vectors: Organisms that Vectors: Organisms that carry the diseasecarry the disease

Most common are ticks and mosquitoes Most common are ticks and mosquitoes through biting.through biting.

Flies can act as a vector by landing in Flies can act as a vector by landing in disease and then on humans. disease and then on humans.

Symptoms of diseaseSymptoms of disease

When a pathogen invades it infects cells of the When a pathogen invades it infects cells of the body. body.

These infected cells are often ruptured, or killed.These infected cells are often ruptured, or killed. Other times toxins are produced that affect specific Other times toxins are produced that affect specific

organs or systems.organs or systems.

Sometimes the symptoms felt are the body’s immune system fighting back.

Disease PatternsDisease Patterns

As an outbreak of a disease spreads a As an outbreak of a disease spreads a number of agencies are notified. number of agencies are notified.

CDC and WHO monitor disease patternsCDC and WHO monitor disease patterns Endemic diseaseEndemic disease EpidemicEpidemic PandemicPandemic

Methods of fighting Methods of fighting diseasedisease

The Immune System – natural The Immune System – natural defensedefense

Antibiotics are a method of Antibiotics are a method of combating infectious disease.combating infectious disease. Attack microorganism’s cells or Attack microorganism’s cells or

cellular processcellular process Do not harm human cellsDo not harm human cells

Immune System: 2 Immune System: 2 components. Specific and components. Specific and Nonspecific ImmunityNonspecific Immunity

Nonspecific Immunity is the first line of defense. Nonspecific Immunity is the first line of defense. Provide a general defense against al pathogensProvide a general defense against al pathogens Slows progression of disease while specific Slows progression of disease while specific

immunity kicks inimmunity kicks in

Barriers: Prevent pathogens from entering the Barriers: Prevent pathogens from entering the bodybody Skin – physical barrier Skin – physical barrier

Layers of dead skin cells and waxes coating the living Layers of dead skin cells and waxes coating the living cells beneath. cells beneath.

Chemical – attacks incoming pathogensChemical – attacks incoming pathogens Saliva, tears, mucus contain enzymes (lysozyme) Saliva, tears, mucus contain enzymes (lysozyme)

that attacks and destroys bacteria cell walls. that attacks and destroys bacteria cell walls. HCl in the stomach kills bacteria if they enterHCl in the stomach kills bacteria if they enter

Nonspecific ResponseNonspecific Response

Cellular defense – A type of Cellular defense – A type of White Blood Cells (WBC) White Blood Cells (WBC) called macrophages called macrophages undergo phagocytosis. undergo phagocytosis.

Interferon – cells infected Interferon – cells infected with a virus secrete a with a virus secrete a protein called interferon protein called interferon which stimulates neighbor which stimulates neighbor cells to make antiviral cells to make antiviral proteins. proteins.

Inflammatory responseInflammatory response

Damaged tissue and invading cells release Damaged tissue and invading cells release proteins which allow for WBCs to get to the proteins which allow for WBCs to get to the area.area.

Specific Immunity – Involves Specific Immunity – Involves Lymphatic SystemLymphatic System

The lymphatic system The lymphatic system filters blood and lymph filters blood and lymph and destroys and destroys microorganisms.microorganisms.

Destroys fatDestroys fat Lymph is a clear fluid that Lymph is a clear fluid that

bathes body cells and is bathes body cells and is collected by lymph collected by lymph vessels.vessels.

Lymphatic OrgansLymphatic Organs

Each of the following organs is made of Each of the following organs is made of lymph tissues, lymphocytes, and lymph tissues, lymphocytes, and connective tissue. connective tissue.

Lymph nodesLymph nodes TonsilsTonsils SpleenSpleen ThymusThymus

Components to the Components to the Immune SystemImmune System

Macrophages – phagocytosisMacrophages – phagocytosis

Helper T Cells – activate B Helper T Cells – activate B and cytotoxic T cellsand cytotoxic T cells

B Cells – Create antibodies B Cells – Create antibodies and memory cellsand memory cells

Cytotoxic T Cells – direct Cytotoxic T Cells – direct attack on invading pathogensattack on invading pathogens

Specific Immunity – B Cell Specific Immunity – B Cell ResponseResponse

B Lymphocytes are found in B Lymphocytes are found in all lymph tissue. They have all lymph tissue. They have the role of being antibody the role of being antibody factories. factories.

Antibodies are proteins made Antibodies are proteins made by B lymphocytes that target by B lymphocytes that target specific foreign antigens.specific foreign antigens.

Antigens are anything foreign Antigens are anything foreign to the body that cause immune to the body that cause immune responses. responses.

B Cell ResponseB Cell Response

Macrophages present Macrophages present antigens on their surface. antigens on their surface. This antigen is called a This antigen is called a processed antigen. processed antigen.

The macrophage then The macrophage then binds to a helper T Cell binds to a helper T Cell (Another type of (Another type of lymphocyte). lymphocyte).

The helper T Cell is now The helper T Cell is now considered “activated”.considered “activated”.

B Cell ResponseB Cell Response

The activated helper T Cell go on to The activated helper T Cell go on to activate B cells and cytotoxic T activate B cells and cytotoxic T cells.cells.

When activated B Cells divide and When activated B Cells divide and mature into plasma cells and are mature into plasma cells and are given instructions to make specific given instructions to make specific antibodies to the antigen found.antibodies to the antigen found.

The activated B cell creates the The activated B cell creates the active plasma cell and memory active plasma cell and memory

cells.cells.

B Cell ResponseB Cell Response

The antibodies The antibodies attach to the attach to the foreign antigen and foreign antigen and cause clumping, cause clumping, making it easy for making it easy for macrophages to macrophages to destroy themdestroy them

T Cell ResponseT Cell Response

The helper T cells also The helper T cells also activate cytotoxic T cells. activate cytotoxic T cells. 1. These cytotoxic T cells 1. These cytotoxic T cells

release cytokines which release cytokines which signals the immune system signals the immune system to activate.to activate.

2. The cytotoxic T cells also 2. The cytotoxic T cells also directly attack pathogens directly attack pathogens and destroy them. and destroy them.

Types of ImmunityTypes of Immunity

Primary Response – first response to an Primary Response – first response to an invasion in the body. invasion in the body.

Passive Immunity – A form of temporary Passive Immunity – A form of temporary protection against a pathogen. The antibodies protection against a pathogen. The antibodies are made by other humans/animals and are made by other humans/animals and injected into the infected patient. injected into the infected patient. Done for people exposed to rabies, tetanus, Done for people exposed to rabies, tetanus,

hepatitis and venoms. hepatitis and venoms. Also done by pregnant mothers, passing antibodies Also done by pregnant mothers, passing antibodies

through the placenta to the developing fetus. through the placenta to the developing fetus.

Types of ImmunityTypes of Immunity

Active Immunity – The memory cells Active Immunity – The memory cells produced by B cells maturing are produced by B cells maturing are involved in long-term memory of involved in long-term memory of pathogens. pathogens.

This type of immunity is a result from This type of immunity is a result from a previous infection OR a previous infection OR immunization. immunization. Immunization is when a weakened/dead Immunization is when a weakened/dead

strain of a pathogen is injected into the strain of a pathogen is injected into the body so that a first response can occurbody so that a first response can occur

Booster ShotsBooster Shots

After the first After the first injection antibodies injection antibodies are made.are made.

A second injection A second injection is made to further is made to further boost the amount boost the amount of of antibodies/memory antibodies/memory cells made. cells made.

Immune System FailureImmune System Failure

Certain disease attack the immune Certain disease attack the immune system directly. system directly.

HIV is a virus that infects helper T cells.HIV is a virus that infects helper T cells. These T cells become HIV producing These T cells become HIV producing

factories.factories. As a result the immune system cannot As a result the immune system cannot

fight other diseases over time. fight other diseases over time.