Immune System 1 What It’s All About – the BASICS Defend the body against pathogens Recognize...
-
Upload
ella-jordan -
Category
Documents
-
view
215 -
download
0
Transcript of Immune System 1 What It’s All About – the BASICS Defend the body against pathogens Recognize...
Immune System
1
What It’s All About – the BASICS
• Defend the body against pathogens• Recognize self from non-self • Specific and Non-specific
“Bottom line”:
Fight infection through the production of cells that inactivate foreign substances/cells
2
Protection
• Pathogens– Infectious disease– Toxic– Reproduce in the host– GERMS
• Koch’s postulate
3
4
4 ways of getting sick
• Contact an infected person directly
5
4 ways of getting sick
• Contact an infected person INdirectly
6
4 ways of getting sick
• Eat infected food or drink infected water
7
4 ways of getting sick• Get bitten by an infected animal
8
Bubonic Plague
Bubonic plague is an infectious disease, circulating mainly among small rodents and their fleas. Without treatment, the bubonic plague kills about two thirds of infected humans within 4 days. Swollen lymph glands are typical symptoms of the plague. During the 14th century, 25 million people in Europe were belived to have died (around 40% of the entire population). 9
Immune System Anatomy
• Lymphatic System–Lymph (fluid with WBCs)–Lymph nodes (store WBCs)–Tonsils, thymus, spleen, appendix, red
bone marrow, adenoids
10
11
Line up the Troops• First line of defense is non-specific
– Blocks anything from entering body system
12
First Line of Defense Examples
• Skin: wall that blocks pathogens• Sweat: acidic, salty, contains enzymes• Mucus: coats openings to body• Tears: wash out pathogens entering eye
13
If that didn’t work….
• Second line of defense: Inflammatory ResponseWhen the pathogen enters the body
– Injured cells release HISTAMINE• Capillaries expand so blood flow increases• Fluid leaks out into space between cells
– Swelling, redness, pain, heat
14
SPECIFIC DEFENSEIMMUNE RESPONSE
– Specific for pathogen– Most effective if you’ve been infected
before– Through entire body– Triggered by substance in pathogen =
antigen– Can be defense in body fluids (humoral) OR
defense against abnormal cells or pathogens (cell-mediated)
15
Cells InvolvedWhite Blood cells = LEUKOCYTES
They are made in the bone marrow
Some develop in bone marrow, others in the thymus
16
Cells Specifics
Non-specific:
Phagocytes: engulf (eat) and digest pathogens
Macrophages are the biggest
Specific: Lymphocytes: B-cells and T-cells
17
Humoral Immunity – Immunity against pathogens in body fluids
Some B cells recognize specific pathogen• B cells mature in Bone marrow• Antibodies from B-cells • Some B cells remember specific antigens &
will produce antibodies whenever the pathogen reappears (memory cells)
• Antibodies:– Attach to antigen and attract macrophages
18
B cell immune response10 to 17 days for full response
invader(foreign antigen) B cells + antibodies
Y
Y
YY
Y
Y
Y
Y
Y
Y
YY
Y
Y
Y
Y
Y
Y
YY
Y
Y
Y
Y
Y
Y
YY
Y
Y
Y
Y
Y
Y
YY
Y
Y
Y
Y
Y
Y
YY
Y
Y
Y
Y
recognition
Y
Y
YY
Y
Y
Y
Y
clone1000s of clone cellsY
Y
YY
Y
Y
Y
Y
Y
Y
YY
Y
Y
Y
Y
Y
Y
YY
Y
Y
Y
Y Y
Y
YY
Y
Y
Y
Y
Y
Y
YY
Y
Y
Y
Y
plasma cellsrelease antibodies
Y
Y
Y
YY
Y
Y
YY
YY
Y
Y
memory cells“reserves”
Y
Y
YY
Y
Y
Y
Y
Y
Y
YY
Y
Y
Y
Y
Y
Y
YY
YY
Y
Y
Y
Y
YY
YY
Y
Y
Y
Y
YY
Y
YY
Y
Y
YY Y
YY
Y
Y
Y
Y
Y
YY
Y
Ycapturedinvaders
19
tested by B cells(in blood & lymph)
Lymphocytes: B-cell
20
Cell-Mediated Immunity
• Cells directly attack and destroy Ag (antigen)– Cancer cells, infected body cells, invading cells
• T cells involved– Born in bone marrow but mature in Thymus– 3 types: killer, helper, suppressor
21
T cells
• Killer T cells– Attack Ag (puncture cell membrane)
• Helper T cells (aka T4)– Stimulate Killer Ts to divide, stimulate B cells to
divide and release Antibodies
• Suppressor T cells– Stop the activity of other T cells
22
T cell response
stimulateB cells &antibodies
Y
Y
YY
Y
Y
Y
Y
Y
Y
YY
Y
Y
Y
Y
Y
Y
YY
Y
Y
Y
Y
Y
Y
YY
Y
Y
Y
Y
YYY
Y
Y
Y
Y
Y
killerT cell
activatekiller T cells
or
infected cell
helperT cell
helperT cell
helperT cell
helperT cell
helperT cell
activatedmacrophage
23
Lymphocytes From Stem Cells
24
Lymphocytes: T-cell
25
Memory CellsPrimary response: new pathogen, new response (5-10 days until max production of B and T cells)
Secondary Response: same pathogen, old response (1-2 days, so you don’t even get sick!)
Memory cells can last your entire life!!
26
Vaccinations • Immune system exposed
to harmless version of pathogen – triggers active immunity– stimulates immune system to produce
antibodies to invader– rapid response if
future exposure
• Most successful against viral diseases
27
Immune response
free antigens in blood antigens on infected cells
humoral response cellular response
B cells T cells
macrophages(APC)
helperT cells
plasmaB cells
memoryB cells
memoryT cells
cytotoxicT cells
YYY
Y
YY
Y
YantibodiesY
Y Y
skinskinpathogen invasionantigenexposure
28
HIV and AIDS
• HIV attacks T4 cells (Helper T cells)• Body can’t defend against any Ags!• Known as an STD: transported in semen, blood,
breast milk
• Once T4 count is so low that body can’t fight disease, we say the person has AIDS
• Takes about 10 years to develop AIDS
29
AIDS Infection
30
Huge Outbreak in Africa
African Children Orphaned by AIDS31
32
Allergies
33
Allergies
• Histamine released even though antigen is harmless
• If blood vessels dilate too much: ANAPHYLACTIC SHOCK
34
Autoimmune Disorders
• Immune system attack SELF cells
• Multiple Sclerosis: T cells destroy nerve cells
• Maybe Type 1 Diabetes is attack on pancreas
35
Multiple Sclerosis
36