Transcript Immune-system-powerpoint

The Immune System
The Basics
Immunity – Three Lines of
Defense
• First Line – keep pathogens out!
STOP
– HOW? Skin, Mucus, Tears (+ Lysozyme), cilia, HCl in
stomach to kill bacteria, “good” symbiotic bacteria
• Second Line – oh no, something got in, start
pitchin’ a general defense
– HOW? Phagocytes, Interferons, Complement,
Histamines (red, hot, swollen), inflammatory
response
• Third Line – very specific immune response to
a particular antigen
– HOW? Macrophages, Helper T cells, B-cells,
antibodies, Killer T cells
STOP
Immunity – First Line
Keep pathogens out
• Skin
• Mucus & Cilia
• Lysozyme (enzyme that breaks down
bacterial walls) in tears & saliva
• HCl in stomach to kill bacteria,
Immunity’s Second Line–something got
in so start PItCHIN’ a general defense!
• Phagocytes – WBC that engulf pathogens by phagocytosis
(neutrophils, macrophages)
• InTerferons – chemicals secreted by virus-infected cells that
stimulate neighboring cells to produce defensive proteins
• Complement – group of proteins that attract phagocytes to
foreign cells and cause cell lysis
• Histamines are secreted by basophils and lead to the
INFLAMMATORY RESPONSE (redness, heat, swelling) b/c of
more blood in the damaged area
• Natural Killer Cells – attack and lyse tumor and virus-infected
body cells
3rd Line of Defense = Immune Response
Immunity – Third Line – very
specific immune response to a
particular antigen
• HOW? See the immune system in action!
• Click here
Click here also
A
What do A, B, and C represent?
A = pathogen with antigens on
surface
B = macrophage
B
C
C = antigen presented on surface of
macrophage
What is the difference between B cells
and T cells?
B cells
T cells
Used in the production of
antibodies in fighting
bacteria, viruses and tumor
cells “NON-SELF CELLS”
Used in identifying antigens
and releasing chemicals
which attract macrophages
(big immune cells which
“eat” antigens)
When they encounter a new
antigen, plasma and
memory cells are formed
from the division of a B cell.
The memory cell
remembers the antigen and
which antibody to use while
the plasma cell makes the
antibodies.
They play a large role in
destroying virus-infected
cells, foreign tissues and
tumor cells- “NON-SELF
CELLS”
Main types are Helper T
cells (assist in activating B
cells) and cytotoxic T cells
(recognize foreign cells and
destroy them) .
Play a role in the HUMORAL
response
Play a role in CELLMEDIATED response
Made in the bone marrow
Formed in the thymus
Read a bit about the immune
system by going to this
website…click here.
Primary vs. Secondary Immune
Response
• PRIMARY
• 10-14 days to mount
effective response
• Reaction to first
exposure to antigen
• SECONDARY
• 2-3 days to mount
effective response
• Reaction to second or
later exposure to
antigen
• Stimulates “naïve”
• Stimulates memory
helper T, B and/or killer
helper T, B, and/or killer
T cells
T cells
• Lower antibody
nd
st
2
• Higher antibody
1
concentration
exposure concentration
Concen- exposure
tration of
antibody
Review of the Immune System
Match the cell type with the description
Description
Cell Type
1. Activate either B or T cells, depending
on the type of pathogen.
B ____
2. Eat and present antigen to Helper T
A
cells.____
a. Macrophage
s
b. Helper T
cells
c. Killer T cells
d. Memory
Killer T cells
e. Plasma B
cells
f. Memory B
cells
3. Produce antibodies.E____
4. Involved in a secondary immune
response.
___
D,
F
B
5. Are attacked by HIV. ____
C
6. Cause lysis of cancer cells.____