Chapter 34 - The Immune System and its Diseases

Why is processed meat bad?

It has nitrates and nitrites which are not good to have in the body.

What effect does nitrites have on the body?

They are carcinogens. (Typically are seen to cause colon cancer).

What effect does nitrates have on the body?

They can be turned into nitrites during the cooking, storage, and processing of processed meats.

What are the disease states of the immune system? (9)

- Allergies
- Asthma
- AIDS (HIV)
- Rheumatoid arthritis
- Psoriasis
- IBS (inflammatory bowl disease)
- Lupus
- Type I Diabetes
- Multiple Sclerosis

What is the immune system?

The body's defence against disease causing organisms.

What is innate immuntiy?

Immunity that you have at birth.

What does innate immunity include?

Barriers (ie. skin), phagocytic cells, antimicrobial proteins, the inflammatory response, natural killer cells, acidic environments, etc.

What is adaptive immunity?

Immunity that is activated only after exposure to specific pathogens.

What are they two parts of adaptive immunity?

- The Humoral Response
- Cell-mediated Response

Describe the humoral response.

Where antibodies are defending against infection in body fluids.

What white blood cell is involved in the cell-mediated response?

Uses lymphocytes.

Which response is faster? Innate or adaptive?

Innate.

At first, the adaptive response of new materials are \____, but after that, the second time around it is \____.

slow; fast

What is the interferon mechanism against viral infection?

Includes two cells. Host cell 1 makes the interferon. This cell is killed by the virus. The Host cell 2 is protected against the virus because of the interferon from Host cell 1.

What is interferon?

A defensive protein.

What is phagocytosis?

Cell eating.

What is a mast cell?

A type of white blood cell that produces histamine when stimulated to do so.

What is a neutrophil?

A WBC that phagocytize bacteria and viruses in infected tissue.

What are macrophages?

A large, amoeboid phagocytic WBC that destroys microbes (innate) and is also part of acquired immunity by presenting antigen (ie. flagging).

What are some of the cells involved in the innate immunity response? (5)

- Mast cells
- Natural killer cells
- Monocytes
- Macrophages
- Neutrophils

Inflammation mobilizes what?

The innate immunity response.

Inflammation does what to an area? (4)

- Increase blood flow
- Redness
- Heat
- Swelling

What is the result after inflammation?

Pus.

What is pus?

Dead WBCs, fluid, and tissue debris.

Adaptive immunity can also trigger when what doesn't clear the infection?

When innate defences "fail"/are unable to clear the infection.

What body system helps us fight infections?

The lymphatic system.

What is toxic shock/septic shock?

A severe response of the body. This is usually due to a bacterial infection and causes very low blood pressure (fatal).

What are lymph nodes?

Gland-like structures found inside the lymphatic vessels that help with "cleaning" the lymph.

Valves in lymphatic vessels help prevent what?

Back flow.

What are the two jobs of the lymphatic system?

\#1 - Fight Infection
\#2 - Return tissue fluid back to the circulatory system

What are the two types of lymphocytes?

B cells and T cells.

How is the adaptive immune response different from the innate response?

It is highly specific.

The adaptive immune response can help \_______ the innate immunity response.

amplify

Where do B cells mature?

Bone marrow.

Where do T cells mature?

Thymus.

Where are B cells and T cells produced?

Both made in the bone marrow.

What is the humoral immune response?

Where there is action against free-floating antigens.

What is the cell-mediated response?

Where there is action against infected cells.

B cells produce antibodies, do T cells do too?

No.

What is an antigen?

A toxin or other foreign substance that induces an immune response in the body, especially the production of antibodies. (ie. molecules on the surfaces of viruses, bacteria, mould spores, pollen, housedust, or the cell surfaces of transplanted organs. These all can be free (not membrane bound)).

What is an antibody?

A protein dissolved in blood plasma that attaches to a specific kind of antigen and helps to counter its effects.

There are millions of lymphocytes that are?

Specific for different antigens.

Each antigen may have up too how many receptors for their specific antigen?

100 000

When an antigen attaches to a specific lymphocytes, the body makes what?

More of that specific lymphocyte to take in the antigen.

In B cells, antibodies are produced. How do the interact with antigens?

They float around in plasma and bind to antigens, thus flagging them for destruction by marcophages.

Some B cells become memory cells. What are these?

These are cells that remember how the body should act in the case that this antigen ends up into the body again. This will allow the response to be much faster.

What are effector cells?

These are cells that are highly effective at combating an existing infection. This lasts for only 4-5 days before dying off.

What is the primary immune response?

What happens when the 1st time a B or T cell is exposed to its antigen.

What is the secondary immune system?

Similar to the primary immune response, but is much faster and stronger.

What are helper T cells?

Stimulate the proliferation of B cells (antibody recruitment) and cytotoxic/killer T cells (attach to infected cells to kill them).

What is perforin?

A protein, released by killer cells of the immune system, that destroys targeted cells by creating lesions like pores in their membranes.

What is the flu?

A respiratory infection caused by the influenza virus.

The flu affects what percentage of Canadians annually?

10-25%

What symptoms are included with the flu?

- Headache
- Coughing
- Chills
- Fever
- Aches
- Sneezing
- Throat irritation

What is the typical duration of the flu?

1-2 weeks.

What is pneumonia?

Inflammation of the lungs; can be the result of the flu and is fatal.

Different strains of flus have different proteins including?

H (hemogglutinin) and N (neuramidase) proteins (eg. H1N1) that facilitate cell entry.

How is a vaccine made?

Culture a virulent strain with an avirulent strain inside a host cells (often a chicken egg). The 2 viruses hybridize to form a vaccine strain that contains surface molecules of the virulent strain but lacks genes that cause the disease.
This primes our immune system.

What was the Spanish Flu?

The pandemic of 1918-1919. This spread worldwide and was estimated to have affected 500 million people (1/3 of the global population). IT killed 20-40 million people. This is an H1N1 strain

What was the Swine Flu?

Also an H1N1 strain. As of 2010, there have been 20 000 people that have been killed by this flu, however, it is now no longer considered a major threat.

Is there such thing as the stomach flu?

No. Most short term gastrointestinal issues are caused by norovirus or rotavirus.

Food poisoning is commonly caused by what virus?

Norovirus.

What is the common cause of diarrhea among children?

Rotavirus.

What are the treatments for norovirus and rotavirus infections?

To prevent, wash your hands! To treat, lots of rest, clear fluids, no dairy, and simple to digest "white foods" that will give your digestive system a break.

Do immunizations cause autism?

No.

When the immune system goes wrong, there are three basic reasons. What are they?

- A hyperactive immune system
- A poorly functioning immune system
- An immune system that attacks itself

What is a hyperactive immune system?

It is where the immune system becomes hypersensitive to regular environmental proteins (results in allergies, asthma, eczema).

What is a poorly functioning immune system?

When the immune system fails to recognize irregular cells and allows for their continued growth instead of destruction. Cancer can develop or Severe Combined Immunodeficiency Disease (SCID), temporary acquired immune deficiencies, and AIDS.

Describe an immune system that attacks itself.

When the immune system fails to recognize "self", then autoimmune disorders arise (Rheumatoid Arthritis, Type I Diabetes, Lupus, IBD, MS, etc.)

What are the main proteins that identify our cells as self?

Major Histocompatibility Complex molecules, or MHCs.

Are MHCs unique?

Yes. (Like a fingerprint, however identical siblings have the same MHCs).

What is the cause of rejection of transplanted organs?

MHCs.

What are allergies?

A disorder of the immune system caused by an abnormally high sensitivity to an antigen.

Symptoms of allergies are triggered by what?

The release of histamines from mast cells.

What is an allergen?

An antigen that causes an allergic reaction.

What is histamine?

A chemical alarm signal released by injured cells or mast cells in response to an antigen. They cause an inflammatory response in the body. This causes blood cells to dilate.

What is antihistamine?

A drug that interferes with the action of histamine. It provides temporary relief from an allergic reaction.

The first exposure to an allergen is called what?

Sensitization.

Describe sensitization.

The first exposure, the allergen binds to an effector B cell, and the B cell proliferates through clonal selection and secretes a large number of antibodies. Antibodies then attach themselves to mast cells, thus causing the release of histamine and other chemicals that trigger an inflammatory response.

The second time some is exposed to an allergen, what happens?

Once the allergen enters the body, it binds to the antibodies attached to the mast cells causing them to release histamine. The result \= an allergic reaction which can include the dilation of blood vessels that leak fluid, nasal irritation, itchy skin, and tears.

What is anaphylactic shock?

An extreme, often life-threatening allergic reaction to an allergen to which the body has become hypersensitive.

What are some common allergens?

- Bee venom
- Penicillin
- Peanuts
- Shellfish

An EpiPen is used to treat severe allergic reactions. What does it have?

Epinephrine because it can counteract the effects of histamine.

What are some reasons for allergies and autoimmune disorders?

- Hygiene hypothesis
- Pollution effects the immune system

What is asthma?

Where airways become so narrow that it is difficult to breathe.

What are some symptoms of asthma?

- Wheezing
- Coughing
- Shortness of breath
- Breathlessness when exercising
- Chest tightness

What are some risk factors of asthma?

- Genetics
- Low birth weight
- Having another allergy-related condition (ie. hay fever, eczema)
- Prenatal tobacco smoke exposure
- Prenatal maternal stress
- Antibiotic use

Is asthma more common in boys than girls?

Yes.

What are the two basic kinds of asthma?

- Allergic (caused by an allergen)
- Non-allergic (auto-immune caused)

What is eczema?

An inflammation of the skin that usually presents as an itchy rash.

What is the scientific name of eczema?

Atopic dermatitis.

Eczema can be triggered by what?

Foods like nuts, wheat, dairy, pollen, and smoke, fragrances, metals like chronium, cobalt, nickel, various preservative agents including those that release formaldehyde.

What is eczema often treated with?

A topical corticosteroid cream.

What are some issues of a poorly functioning immune system?

- Severe Combined Immunodeficiency (SCID)
- Temporary acquired immune deficiencies
- AIDS (Acquired ImmunoDeficiency Syndrome)

What is Severe Combined Immunodeficiency (SCID)?

Born with a weak immune system that doesn't protect the body from bacteria, viruses, or fungi due to a lack of white blood cells.

What are temporary acquired immune deficiencies?

Things that temporarily cause the immune system to become compromised. (ie. chemotherapy, medicines to prevent organ rejection, smoking, alcohol, poor nutrition, and lack of sleep).

What is AIDS?

Caused by HIV (human immunodeficiency virus). It destroys important white blood cells and weakens the immune system.

What are some autoimmune diseases?

- Rheumatoid Arthritis
- Type I Diabetes
- Lupus
- Psoriasis
- Inflammatory Bowel Disease (IBD; includes Ulcerative Colitis and Crohns Disease).

What is Rheumatoid Arthritis?

Swelling and deformities of the joints caused by the immune system sending antibodies that attack the lining of the joints.

What is Type I Diabetes?

Where the immune system attacks the pancreas and reduces it's ability to make insulin. Causes elevated blood sugars and possibly blindness, heart, kidney, and neurological diseases etc.