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Chapter 43 Immune System
Figure 43.1 An overview of the body's defenses
Traps microbes
Ex. Lysozyme - protective
protein
Found: upper respiratory
tract
Opeing around eyes (tears,
mucus)
- edema (swelling)
-
redness
-
pain
-
blood flow
Ex. Interferons - secreted by
virus infected Bells, causes other
cells to produce chemicals to
inhibit viral reproduction
Lymphocytes –
B cells
T cells
Antibodies - proteins that
attack
antigens
(foreign molecules)
Figure 43.4 The human lymphatic system
Lymphatic system:
-
returns fluid from interstitial spaces
- location where lymphocytes
develop
T cells
B cells
Leukocytes – any white blood cell
B cells
T cells
Macrophages
Monocytes
Figure 43.5 A simplified view of the inflammatory response
triggers
inflamation
Injured cells release chemicals:
blood vessels and increases permeability of _______________
capillaries
1. Histamine - causes dilation of ________________
promotes blood flow
2. Prostaglandins - also ________________________________________________________
Fever can also result from infections
inhibiting growth of microorganisms
- moderate fever helps with defense by _______________________________________________
-
facilitates phagocytosis
repair
- increase body reactions for ___________________________
* septic shock - caused by a large systemic inflammatory response
- high fever
-
low blood pressure
Antigens activate specific
2 types: 1. B cells
Figure 43.6 Clonal selection
Membrane antibodies
also called
foreign
2.
T cells
Different receptors on B cells
- only one receptor fits
the antigens shape
membrane
immunoglobulins
Ex. Occurs due to:
virus
bacteria
fungi
protozoa
parasitic worms
pollen
Long lived cells: can respond quickly to the next
to the same
Clone of B cells
Clone of B cells can either
develop into:
memory cells
clone plasma cells
Short lived plasma cells, also called
Secrete
antibodies
Specific
to the antigen
effector cells
Figure 43.7 Immunological memory
Primary immune
response
Responsible for initiating a
• Effector B cells
plasma cells
(make antibodies)
•Effector
T cell response
Memory cells proliferate at:
initial exposure and second
exposure
secondary immune
response
Figure 43.8 The development of lymphocytes
Lymphocytes are white blood cells
Two types:
T cells (develop in thymus)
B cells (develop in bone marrow)
Found:
B cells and T cells must distinguish self from
nonself, if not:
- autoimmune diseases, have no
self tolerance
Both B and T cells have specific
antigen receptors
Develops in:
Develops in:
Figure 43.9 The interaction of T cells with MHC molecules
Antigen presenting cell:
APC
Found on:
Found on:
- macrophages
almost every
cell in the
body
- B cells
- T cells
- inside
thymus
Major histocompatibility complex
-
distinguishes self from non-self
identifies abnormal cells
Figure 43.10 An overview of the immune responses
Involves B cell activation
with the production of
antibodies
Defends against:
1. free bacteria
2. toxins
3. viruses in body
fluids
Involves cytotoxic
T cell activation
Defends against:
1. cells infected
by virus or
bacteria
2. fungi
3. protozoa
4. parasitic worms
responds to
transplants and
cancer cells
Figure 43.11 The central role of helper T cells: a closer look
protein
antigen presenting cell
Cytokines - proteins that stimulate
other lymphocytes
ex. interleukin 1, interleukin 2
the surface using a class II MHC molecule
1. APC engulfs bacteria, transports to ______________________________________________
MHC antigen complex
2. A specific TH cell binds to the __________________________________________________
APC enhances TH cells to secrete interleukin-2
interleukin-1 secreted by the __________________________________________________
T cells and memory T cells
H
3. TH cell proliferates into more___________________________________________________
other cytokines and interleukin-2 are secreted
T cells and activates B cells and T cells
H
C
4. Cytokines stimulate __________________________________________________________
Figure 43.12a The functioning of cytotoxic
T cells
antigen using a class I MHC molecule
1. Infected cells displays _______________________________________________________
MHC antigen complex
TC cell binds to the __________________________________________
perforin
2. TC cell releases ______________
creates pores in the membrane of the infected cell
_______
into infected cell
3. Water and ions flow _________________________
cell lysis
________________________
Figure 43.13 Humoral response to a T-dependent antigen
Figure 43.14 Epitopes (antigenic determinants)
Antibodies -
a group of proteins called
immunoglobulins
disease or vaccination
Active immunity - immunity from an infectious _________________________________________
placenta
Passive immunity - mother to fetus through the __________________
breast milk
antibodies
passes __________________
also through ________________________________
Blood type:
type A blood
type B blood
A
contains _______ antigens
B
contains _______
anitgens
A, B
type AB blood
contains _______ antigens
type O blood
no antigens
contains _______
Rh factor can cause fetus RBC’s to be destroyed
antibodies
*blood contains _______________
antigens
to fight ____________________
after a transfusion
Figure 43.16 Effector mechanisms of humoral immunity
Figure 43.20 The stages of HIV infection