End Show Slide 1 of 31 Copyright Pearson Prentice Hall Biology LB: Use cover that doesn’t have...

Copyright Pearson Prentice Hall

End Show

Slide 1 of 31

Biology

LB:

Use cover that doesn’t have sticker on it

LB:

Use cover that doesn’t have sticker on it


End Show

Slide 2 of 31

40-3 Immune System Disorders

Ragweed Pollen


End Show


Slide 3 of 31

Immune Disorders

Although the immune system defends the body against pathogens, sometimes disorders occur in the immune system itself.

There are three different types of immune system disorders:

• allergies

• autoimmune diseases

• immunodeficiency diseases


End Show


Slide 4 of 31

Allergies

Allergies

Overreactions of the immune system to antigens are allergies.

Common allergies include pollen, dust, mold, and bee stings.

Antigens that cause allergic reactions are called allergens.


End Show


Slide 5 of 31

Allergies

When allergy-causing antigens enter the body, they attach themselves to mast cells.

Mast cells are specialized immune system cells that initiate the inflammatory response.

The activated mast cells release histamines.


End Show


Slide 6 of 31

Allergies

Histamines increase the flow of blood and fluids to the area.

They increase mucus production in the respiratory system, which induces sneezing, watery eyes, and runny nose.

Antihistamines are drugs that counteract histamines.


End Show


Slide 7 of 31

Asthma

Asthma

Some allergic reactions cause asthma.

Asthma is a chronic respiratory disease in which the air passages become narrower than normal.

This causes wheezing, coughing, and difficulty in breathing.

If not treated, asthma can lead to permanent damage or destruction of lung tissue.


End Show


Slide 8 of 31

Autoimmune Diseases

Autoimmune Diseases

What is an autoimmune disease?


End Show


Slide 9 of 31

Autoimmune Diseases

When the immune system attacks the body's own cells, it produces an autoimmune disease.


End Show


Slide 10 of 31

Autoimmune Diseases

Some examples of autoimmune diseases include:

• Type I diabetes attacks insulin-producing cells.

• Rheumatoid arthritis attacks connective tissues around joints.

• Myasthenia gravis attacks neuromuscular junctions.

• Multiple sclerosis (MS) destroys functions of brain and spinal cord neurons.


End Show


Slide 11 of 31

Autoimmune Diseases

Some autoimmune diseases are treated with medications that alleviate specific symptoms.


End Show


Slide 12 of 31

Immunodeficiency Diseases

Immunodeficiency Diseases

An immunodeficiency disease is one in which a person has a weakened immune response.

In one type of immunodeficiency disease, the immune system fails to develop normally.

A second type of immunodeficiency disease is AIDS.


End Show


Slide 13 of 31

AIDS

In 1983, researchers identified the cause of AIDS—a virus that is caused by the HIV for human immunodeficiency virus.

HIV is a retrovirus—a virus that carries its genetic information in RNA, rather than DNA.


End Show


Slide 14 of 31

AIDS

HIV attacks and destroys helper T cells.

As the number of helper T cells decreases, the body becomes more susceptible to other diseases.

The diseases that attack a person with a weakened immune system are called opportunistic diseases.


End Show


Slide 15 of 31

AIDS

HIV Infection


End Show


Slide 16 of 31

AIDS

Reverse transcriptase enzyme

Envelope

Virus attaches to host cell membrane by recognizing specific molecules on the cell surface.

Viral RNA

Capsid

Protein coat

1

1


End Show


Slide 17 of 31

AIDS

Viral coat fuses with cell membrane and viral RNA enters the cell

2

2


End Show


Slide 18 of 31

AIDS

Reverse transcriptase uses viral RNA as a template to make viral DNA. 3

3


End Show


Slide 19 of 31

AIDS

Viral DNA enters nucleus and attaches to host chromosome. There it may remain dormant or begin directing the synthesis of viral mRNA and RNA.

4

4


End Show


Slide 20 of 31

AIDS

Viral mRNA directs the host cell to assemble viral proteins.

55


End Show


Slide 21 of 31

AIDS

Capsids are assembled around the viral proteins and RNA. The new viruses bud off from the host cell membrane.

6

6


End Show


Slide 22 of 31

AIDS

Transmission of HIV

HIV is not transmitted through casual contact.

HIV can only be transmitted through the exchange of blood, semen, vaginal secretions, or breast milk.


End Show


Slide 23 of 31

AIDS

How can AIDS be prevented?


End Show

Slide 24 of 31

40-3 Immune System Disorders AIDS

Preventing HIV Infection

The only no-risk behavior with respect to HIV and AIDS is abstinence.

People who share contaminated needles to inject themselves with drugs are at a high risk for contracting HIV.

People who have sex with drug abusers are also at high risk.


End Show


Slide 25 of 31

AIDS

Can AIDS Be Cured?

At present, there is no cure for AIDS.

The virus can be controlled by expensive multidrug and multivitamin “cocktails” that fight the virus.


End Show

- or -Continue to: Click to Launch:

Slide 26 of 31

40-3


End Show

Slide 27 of 31

40-3

Allergies result when antigens from allergens bind to

a. histamines.

b. pathogens.

c. mast cells.

d. T cells.


End Show

Slide 28 of 31

40-3

An example of an autoimmune disease is

a. polio.

b. multiple sclerosis.

c. asthma.

d. smallpox.


End Show

Slide 29 of 31

40-3

In Type I diabetes, antibodies attack

a. connective tissues around the joints.

b. neuromuscular junctions.

c. insulin-producing cells in the pancreas.

d. epinephrine-producing cells in the adrenal cortex.


End Show

Slide 30 of 31

40-3

The retrovirus HIV causes

a. AIDS.

b. myasthenia gravis.

c. asthma.

d. polio.


End Show

Slide 31 of 31

40-3

The principle targets of the HIV virus are the body’s

a. red blood cells.

b. helper T cells.

c. connective tissue in the joints.

d. B cells.

END OF SECTION

End Show Slide 1 of 31 Copyright Pearson Prentice Hall Biology LB: Use cover that doesn’t have...

Documents

Transcript of End Show Slide 1 of 31 Copyright Pearson Prentice Hall Biology LB: Use cover that doesn’t have...