The Immune System - Valhalla High School
Download
Report
Transcript The Immune System - Valhalla High School
The Immune System
Dr. Timmel
What is disease?
Any change, other than an injury, that
disrupts the normal functions of the body.
What this really means is that something is
forcing your body out of equilibrium.
If an organism is in a disease condition for
too long a period of time, death will ensue.
What are pathogens
Pathogens are disease causing agents.
Diseases caused by pathogens are
generally called infectious diseases.
Examples of pathogens are:
Viruses (the flu, the common cold, warts)
Bacteria (strep throat, anthrax)
Protists (malaria, sleeping sickness)
Worms (tapeworms)
Fungi (Athlete’s foot)
What is the function of the immune
system?
To fight infection through the production of
cells that inactivate foreign substances or
cells.
Some defenses are non-specific and some
are specific.
These defenses work together to both
prevent and fight off disease.
Non-specific defenses
First line of defense: The bodies most
important nonspecific defense is the skin.
This first line of defense also consists of
mucus, sweat and tears.
Consists of physical and chemical
defenses.
Any break in the skin is a possible avenue
into your body for a disease causing
agent.
Second line of defense
The inflammatory response. A
nonspecific response to tissue damage
caused by injury or infection.
Infected tissue may become swollen and
painful.
A fever is often a component of the
inflammatory response.
What are antigens?
A foreign substance which triggers a
response by your immune system.
Viruses, bacteria and other pathogens are
examples of antigens.
The antigen is what is making you sick.
What are antibodies
Antibodies are proteins that recognize and
bind to antigens, inactivating them.
Each antibody is specific to a certain
antigen.
Once a particular antibody is produced by
a body, memory B-cells become capable
of quickly producing them should the body
encounter the same antigen in the future.
Vaccination
The injection of a weakened or killed form
of a pathogen to produce immunity.
Vaccines give the patient an active
immunity against a particular disease and
have saved millions of lives.
Allergies : Is when the body initiates and
inflammatory response to a subestance
which is harmless, such as dust. (Also
pollen, cat dander, shellfish or peanuts).
Lymphocytes
•
•
As we should recall from the circulatory system, there are
four different types of white blood cells.
Phagocytes: Cells engulf and destroy pathogens.
Macrophages: Very large phagocytes. Assist the
activation of B and T Cells.
T-Cells: Provide a defense against abnormal cells and pathogens
inside living cells. T-Cells are formed in the Thymus gland. ( 2 types:
Helper and Killer T cells.)
B-Cells: Provide immunity against pathogens and
antigens in the body fluids. B-Cells are formed in the
Bones. ( These cells produce the antibodies that disable
the pathogen
Autoimmune disease
When the body’s own immune system
attacks its own cells.
The immune system produces “antiself”
antibodies.
Examples are type one diabetes, MS and
AIDS.
AIDS
Acquired Immune Deficiency Syndrome.
A viral disease in which the body’s T-cells
are destroyed, leaving the body
susceptible to secondary infections.
Causes by the HIV (Human
immunodeficiency virus). It is a retrovirus,
meaning it contains RNA and not DNA
What is lymph?
It is a clear fluid that is lost by the blood to
the surrounding tissue.
Travels through the lymphatic system: A
network of vessels, nodes and organs
which collects fluids and returns them to
the circulatory system.
Contains a large number of white blood
cells.
What are lymph nodes?
Part of the lymphatic system, lymph nodes
are small bean shaped enlargements that
filter the lymph and capture bacteria and
other microorganism that cause disease.
When the doctor says you have swollen
glands, they are actually referring to your
lymph nodes. They get larger when you
are fighting an infection.
Other organs of the immune
system
In addition to lymphocytes, lymph and
lymph nodes, one gland and one other
organ play important roles.
Thymus gland. As mentioned earlier, TCells mature in the thymus gland.
Spleen: helps to cleanse the blood and
remove damaged cells from the circulatory
system. Also contains phagocytes.