Transcript Notes: Chapter 39 Reading Guide (page 1022

Notes: Chapter 39 (page
1022-1047) – Immunity from
Disease
Pathogens
• Disease causing agents
– Can be bacteria, protists, fungi, viruses, or
parasites like tape worms
– Infectious diseases are any diseases caused
by a pathogen
Symbiosis with microorganisms
• Bacteria on our skin and intestines help us
digest our food and keep harmful bacteria
from growing and causing illness.
• Helps maintain homeostasis within our
digestive tract
Host cells
• Viruses need
be inside of
host cells in
order to
reproduce
Antibiotics
• A substance that kills or inhibits the growth
or reproduction of other microorganisms.
• Effective against bacteria and some fungi
but NOT VIRUSES.
Antibiotic resistance
• Continued use of antibiotics selects for resistant
bacteria. Soon the antibiotics do not work.
– In the case of penicillin, over-prescribing and failure
to use the entire dose led to resistant bacteria
surviving and reproducing.
Our Immune system
Innate Immunity
•
•
•
•
Body’s first defense
NON-Specific defense (attacks everything)
Skin, saliva, sweat, tears, inflammation
Main cells are macrophages
– Macrophages engulf and kill foreign
invaders
Acquired Immunity
• Second defense
• Goes after specific pathogens (targeted)
• Main cells are lymphocytes
– T-cells and B-cells
Acquired Antibody
Immunity
• Macrophages recognize and engulf a foreign
invader which activates helper T-cells
• Helper T-cells then activate B-cells
• B-cells mature into plasma cells and make
antibodies against the specific pathogen
• Memory B-cells and T-cells hang around in
case the pathogen shows up again later
– Quick response next time
Acquired Cellular Immunity
• Cytotoxic T-cells are killer T-cells that
destroy cancer and virus infected cells but
punching them full of holes
Autoimmune responses
• Allergic reactions are immune
responses to harmless substances
• Autoimmune diseases happens when
the immune system turns on own body
and attacks (example is lupus)
Passive Immunity
• When you are given antibodies made
by someone else. Not lasting
protection
• Antibodies from mother to infant
through the placenta and breast
feeding
• anti-venom
Active Immunity
• Body produces it’s own antibodies
after being exposed to antigens
– Antigens are proteins from
pathogens
• Vaccines are weakened or dead
pathogen that induces a person to
make antibodies
– Gives lasting protection against the
disease through memory cells
AIDS, HIV and the Immune System
• HIV stands for Human Immunodeficiency Virus
• HIV is a retrovirus (RNA) that attacks helper Tcells which prevents the immune system from
working properly
• The causes AIDS (acquired immune deficiency
syndrome)
• Person with AIDS cannot fight off infections and
they may die
• Passed through bodily fluids