Reaves KEY CONCEPT The immune systems consists of organs cells and molecules that fight infections Many other tissues and systems help the immune system Skin is a physical barrier to infection ID: 544854
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Slide1
31.2 – 31.4 Immunity
ReavesSlide2
KEY CONCEPT:
The immune systems consists of organs, cells, and molecules that fight infectionsSlide3
Many other tissues and systems help the immune system
Skin
is a physical barrier to infectionMucous membranes trap pathogens entering the bodyThe circulatory system transports immune cellsSlide4
Cells and proteins fight the body’s infections.
White blood cells attack infections inside the body
Phagocytes engulf and destroy pathogensT cells destroy infected cellsB cells produce antibodiesSlide5
antibody
pathogens
Three types of
proteins
fight off invading pathogens
Complement proteins
weaken pathogen membranes
Antibodies
make
pathogens
ineffective
Interferons
prevent viruses from infecting healthy cellsSlide6
Immunity prevents a person from getting sick from a pathogen.
When you have
immunity, pathogens are destroyed before you get sickPassive immunity occurs withoutan immune responsemother’s milkgeneticsActive immunity occurs after aspecific immune responseSlide7
On your notes!
Create a Y-chart : Passive and Active Immunity p760 Slide8
KEY CONCEPT
The immune system has many responses to pathogens and foreign cells.Slide9
Two types of responses
# 1 Nonspecific Responses-the same for every pathogen
Inflammationblood vessels become leaky.white blood cells movetoward infection anddamaged tissue
D. characterized by swelling, redness, and pain
capillary wall
extracellular
space
white blood cell
E. Fever-body temperature increases.
High fevers can cause seizure, brain damage, and even death.
Low fevers stimulate white blood cells to mature.Slide10
2. Specific Responses
1st detect antigens (surface proteins on pathogens)
Each pathogen has a different antigen.
virus
antigensSlide11
pathogen
antigens
T cell
receptors
activated T cells
antigens
memory T cells
Two types of specific immune responses.
A. Cellular immunity uses T cells to destroy infected body cells.Slide12
.
B. Humoral immunity uses B cells to produce antibodies.
memory B cells
activated B cells
antibodies
B cell
T cell
pathogenSlide13
Both responses produce memory cells.
specialized T and B cells
provide acquired (active) immunity
B cell
T cellSlide14
The immune system rejects foreign tissues.
Tissue rejection occurs in organ or tissue transplants.
Tissue rejection is the result of an immune response.immune system detects protein markers on the donor tissuemakes antibodies against the donor’s tissuehttps://www.youtube.com/watch?v=zQGOcOUBi6sSlide15
Stop!
Complete 31.3 Power Notes Slide16
KEY CONCEPT
Living in a clean environment and building immunity help keep a person healthy.Slide17
Many methods are used to control pathogens.
Antibiotics and antiseptics cause pathogens to burst.Slide18
Antiseptics kill pathogens outside of the body.
do not target specific pathogens
examples include vinegar and soapAntibiotics kill pathogens inside the body.target one specific bacterium or fungusnot effective against virusesSlide19
Antibiotic resistance can cause medicines to become ineffective.
Some bacteria in a population have genes that make them immune to antibiotics.
These bacteria spread the gene, making the antibiotics useless.
A bacterium carries
genes for antibiotic
resistance on a plasmid.
A copy of the plasmid is transferred
through conjugation.
Resistance is quickly
spread through
many bacteria.Slide20
Vaccines artificially produce acquired immunity.
Vaccines also control pathogens and disease.
given to prevent illnesscontain the antigen of a weakened pathogen Vaccine Articlehttps://www.youtube.com/watch?v=rb7TVW77ZCsSlide21
9. What is a vaccine?
A substance that produces active immunity.
What do vaccines do that allow the body to gain immunity without getting sick? Produce memory cells 11. Memory cells do not have to be activated- they respond right away.12.Vaccines are made of : dead, whole pathogens, weak pathogens, pieces of pathogens, bacterial toxinsSlide22
Vaccination provides immunity.
stimulates a specific immune response
allows immune system to respond quickly to infection
causes memory cells to be produced
has such a fast response, a person will not get sick
A memory B cell is
stimulated when the real pathogen binds to it.
2
The B cell quickly activates and makes antibodies that fight the pathogens before you get sick.
3
Antigens in a vaccine
trigger an immune response, and memory B cells are made.
1
memory B cellsSlide23
Stop!
The Science Behind the Flu Shot
Work in pairs.Turn in one answer sheet per pair. (Add both names to sheet!)