Ib Hl Immune System

Front 1

Define pathogen

Back 1

an organism or virus that causes a disease

Front 2

Why are antibiotics effective against bacteria but not viruses?

Back 2

antibiotics block specific metabolic pathways found in bacteria; viruses reproduce using the host cell's metabolic pathways, which are not affected by antibiotics

Front 3

Outline the role of the skin in defence against pathogens

Back 3

The skin is an external, nonspecific defense against pathogens. It is a physical barrier which, if damaged, must be repaired by blood clotting. It is also a chemical barrier because it produces waxes (making it harder for the pathogen to enter) and sweat (which can injure pathogens).

Front 4

Outline the role of the mucous membranes in defence against pathogens

Back 4

The skin is an nonspecific defense against pathogens. It is a physical barrier which. It is also a chemical barrier because it produces mucus, which makes it harder for the pathogen to enter.

Front 5

What do phagocytic leucocytes do?

Back 5

They ingest pathogens in the blood and body tissues by phagocytosis (make sure you know what that is). Once the phagocytic leucocytes/macrophages ingest the pathogen, they break it down using the enzymes in their lysosomes. Antigens are displayed on the surface in an MHC protein; at this point you can call the cell an antigen-presenting cell. It will travel to the lymph node to stimulate helper T cells

Front 6

Define antigen

Back 6

Substances (molecules) which can stimulate the production of antibodies. Pathogens have many types of antigens on their cell surface (often membrane proteins or carbohydrates). Keep in mind that human cells also have antigens. We recognize our own antigens as "self." If you get a transplant or a blood transfusion from another human with different antigens then your immune system will respond to that new tissue/blood.

Front 7

Define antibody

Back 7

A Y-shaped protein that recognizes and binds to specific antigens. (Make sure you understand the difference between antigen, antibody, and antibiotic…don't mix them up!)

Front 8

Explain antibody production

Back 8

IB topic 6: "Many different types of lymphocytes exist. Each type recognizes one specific antigen and responds by dividing to form a clone. This clone then secretes a specific antibody against the antigen." IB topic 11 adds more: Macrophage ingests pathogen and presents antigen on MHC protein. Antigen-presenting cell goes to lyph node and activates helper T cells (only the helper T cells that can help fight the disease are activated; those cells divide rapidly; "clonal selection"). Helper T cells activate B cells (clonal selection). Some of these differentiate into plasma cells, which produce antibodies; others differentiate to become memory cells.

Front 9

What do helper T cells do? How are they activated?

Back 9

Activate B cells and cytotoxic T cells. Activated by antigen-presenting cells/macrophages/phagocytic leucocytes by clonal selection.

Front 10

What do B cells do? How are they activated?

Back 10

B cells differentiate into plasma cells and memory cells (see other flashcards). Activated by helper T cells and antigen .

Front 11

What do plasma cells do? Where do they come from?

Back 11

They secrete antibodies. They are a type of B cell (undifferentiated B cells divide during clonal selection and then differentiate into plasma cells and memory cells)

Front 12

What do memory cells do? Where do they come from?

Back 12

They allow your body to respond very quickly (lots of antibodies made really fast) the NEXT time you are exposed to the pathogen.. They are a type of B cell (undifferentiated B cells divide during clonal selection and then differentiate into plasma cells and memory cells)

Front 13

What do cytotoxic cells do? How are they activated?

Back 13

Kill virus-infected cells and cancerous cells. Activated by helper T cells and antigen .

Front 14

If you have a bacterial infection, what specific defences let you kill it?

Back 14

Antibodies are good against extracellular pathogens and toxins. You want to state this and explain how you produce antibodies (see other flashcards)

Front 15

If you have a viral infection, what specific defences let you kill it?

Back 15

Cytotoxic T cells are good against intracellular viruses. You want to state this and explain how you produce cytotoxic T cells (see other flashcards)

Front 16

What are some internal, non-specific defenses?

Back 16

Fever, inflamation, phagocytosis by macrophages

Front 17

What is a polyclonal response?

Back 17

When multiple types of antibodies are produced. This is the case when you are infected with a pathogen because it has multiple types of antigens on its surface

Front 18

What is a monoclonal antibody?

Back 18

antibodies produced artificially that bind to one type of antigen only

Front 19

How are monoclonal antibodies made?

Back 19

1)      Fuse together a tumor cell and a B-cell a) B-cells produce antibodies (you’ll need the one that makes the specific type of antibody you want) b) Tumor cells divide rapidly and cell lines descended from them tend to live longer 2) Hybrid cell will proliferate 3) Hybrid cells will produce antibodies, which you can use in diagnosis and treatment

Front 20

What are some uses of monoclonal antibodies in treatment?

Back 20

Targeting cancer cells with drugs attached to monoclonal antibodies; Emergency treatment of rabies or snake bite; Purification of industrially made interferon; Destroying T cells to reduce the rejection of transplants

Front 21

What are some uses of monoclonal antibodies in diagnosis?

Back 21

Pregnancy testing (antibody to human chorionic gonadotropin (HCG))…uses ELISA; HIV testing (antibodies to look for antibodies against HIV)…uses ELISA; Heart attack diagnosis (antibodies to look for a specific cardiac isoenzyme)…uses ELISA; Blood and tissue typing for transplant compatibility; Testing for (different strains of) malaria

Front 22

Define active immunity and give examples

Back 22

immunity due to the production of antibodies by the organism itself after the body’s defense mechanisms have been stimulated by antigens”; immunity due to disease or vaccination

Front 23

Define passive immunity and give examples

Back 23

"immunity due to the acquisition of antibodies from another organism in which the active immunity has been stimulated” ; antibodies through placenta to baby, antibodies in colostrum (breast milk) to baby, injection of antibodies (like snake anti-venom)

Front 24

Define natural immunity and give examples

Back 24

immunity due to infection or acquisition from mother; from having a disease yourself and making your own antibodies, antibodies to fetus through placenta, antibodies to baby in breast milk

Front 25

Define artificial immunity and give examples

Back 25

immunity due to vaccination (or other non-infectious process); immunity due to vaccination or injection of antibodies (ie snake anti-venom)

Front 26

If you get sick with a disease once (or get a vaccine) why are you immune from getting it again?

Back 26

You have made memory cells! They allow your body to respond very quickly (lots of antibodies made really fast) the NEXT time you are exposed to the pathogen. Make sure you can draw/label the graph that illustrates this idea!

Front 27

What is clonal selection and where do you see examples of it in the immune response?

Back 27

clonal selection: a small number of lymphocytes are activated and divide rapidly to produce a clone of cells which are all effective against the particular pathogen your body is fighting; Helper T cells (activated by macrophages), B Cells (activated by helper T cells), Cytotoxic T cells (activated by helper T cells)

Front 28

Explain the principle of vaccination

Back 28

1) Inject patient with vaccine which contains a)inactive toxins, fragment of pathogen, killed pathogen, weakened pathogen or weakened pathogen/attenuated virus…you don’t want the person to get sick from the vaccine b)Possibly preservatives or something left over from production process (like egg) 2) Patient’s macrophages will ingest and present antigens 3) Helper T cells bind to macrophages and are activated (clonal selection) 4) Antigen binds to B cells. Then, Helper T cells bind to B cells and activate them by clonal selection (lots of mitosis!). Some are plasma cells that make antibodies to deal with whatever was in the vaccine. Some of these differentiate into memory cells. A)The key thing to note is the role of the memory cells. Now that the patient has memory cells, if he/she is ever infected with the real disease with the same antigens he/she can have a fast secondary response and therefore not experience the symptoms of illness. A graph is ideal to show this B)Second booster shots are somet

Front 29

What are benefits of vaccination?

Back 29

Some diseases, such as small pox, can be totally eliminated*; Prevention of epidemics and pandemics*; Decreased health care costs* (particularly with respect to decreasing disability—blindness, paralysis, etc); Prevention of harmful side-effects of disease* (Rubella in pregnant women can lead to deafness and blindness in the baby; Mumps can cause infertility in men); Deaths can be prevented, ex. from measles. ; Reduce job absenteeism; Disease free cattle/more food; Healthier society (Items with a * are required by IB)

Front 30

What are dangers of vaccination?

Back 30

Possible side effects of mercury in vaccines * (Mercury is used in some vaccines to kill bacteria present in certain vaccines and preserve others from bacterial contamination; Mercury effects: Effects brain development and cognition (larger effect of developing nervous systems of fetuses and children. Also affects functioning of glomerulus in kidney. ;There are now some mercury-free vaccines); Possible overload of immune system * (Excessive amounts of vaccination may reduce the ability of the immune system to cope with new diseases.); Possible links with autism * (MMR (measles, mumps, and rubella) vaccine can increase the chance of autism according to some sources. This may be linked to the use of mercury); Immunity developed after vaccination may not be as effective as immunity due to the actual disease. ; Pregnant women, cancer patients, and others can be harmed by cross-infection from people vaccinated with the live virus, ex. smallpox vaccine. ; Allergic reactions; People with compromised immune system

Front 31

What is HIV?

Back 31

the virus that causes AIDS (human immunodeficiency virus)

Front 32

What is AIDS?

Back 32

the disease caused by HIV (Acquired Immunodeficiency Sydrome)

Front 33

What is the cause of AIDS?/ How does AIDS effect the immune system?

Back 33

Caused by HIV; causes low number of helper T cells; therefore, less B cells are activated and less antibodies are produced; this causes the body to become more vulnerable to pathogens (people with AIDS die from secondary infections or rare cancers that they can't fight off)

Front 34

How is AIDS transmitted?

Back 34

Transmission involves transfer of body fluids; HIV does not live outside the body; Sexual intercourse (vaginal, anal or oral)(small cuts); Childbirth (through cuts w/blood); Through placenta and in breast milk (lower risk); Needle sharing (traces of blood on needles); Blood transfusion (safe in US); blood products/factor VIII used to treat hemaphiliacs (now considered safe in US)

Front 35

What are the social consequences of AIDS?

Back 35

Discrimination: Individuals with HIV may become stigmatized and not find housing, partners or employment; Cost of health care to countries/insurance; Families become poorer if the individual with AIDS was the wage earner and does not have/is refused life insurance. Reduction of workforce; Grief of family and friends ; Orphaned children…family structure/stability affected; Sexual activity in a population may be reduced because of the fear of AIDS (affects people of all ages, sexes, genders, sexual orientations, socioeconomic ststuses, etc)

Front 36

Describe the process of blood clotting

Back 36

Release of clotting factors from platelet results in the formation of thrombin (from prothrombin). Thrombin catalyzes the conversion of soluble fibrinogen into the fibrous protein fibrin, which captures blood cells (making a clot).

Front 37

What sort of drugs are used against bacteria and viruses?

Back 37

Antibiotics for bacterial infections; antivirals for viral infections

Front 38

Do antibiotics and antiviral drugs give you immunity against a disease?

Back 38

no