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Physiology Exam 4: Immune System

STUDY
PLAY
Threat to moral purity induces need to cleanse:
Macbeth Effect
What did Zhong and Liljenquist discover in their experiments in 2006?
people prefer to think clean things and/or to wash hands when given opportunity after recalling an unethical act
-even showed reduced "guilt" after hand-washing
Immunology studies:
physiological defenses by which the body (host) distinguishes self from non-self
Three main functions of the immune system:
1. Protection against disease-causing invaders (pathogens): bacteria, viruses, parisitic micro-organisms "self vs. non-self"
2. Isolate or remove non-microbial foreign substances (includes organic and inorganic materials)
3. Recognize/remove abnormal cells. ex: cancer cells
When the immune system goes wrong (pathologies):
1. incorrect response
2. overactive response
3. no response
Incorrect response:
autoimmune diseases
-failure to distinguish self from non-self
-e.g., Type I diabetes
Overactive response:
allergies
-response out of proportion to threat posed
-annoying to life-threatening
No response:
immunodeficiencies
-primary: genetic defect
-acquired: infection
Two classes of pathogenss are of primary health concern in the US:
Viruses
Bacteria
Viruses:
nucleic acids (RNA) surrounded by a protein coat
Viruses are dependent on:
host cells for replication
which makes them weaker
Bacteria:
outnumber human cells in body 20:1
most are harmless
some are essential for health
Most can reproduce outside a host
Other significant pathogens:
parasites
Malaria:
protozoan parasite develops in mosquito
-transmitted during blood meal
Liver, then invade and reproduce, into bloodstream,, RBC's
~800,000 deaths per year
Lympathic filariasis:
elephantiasis
Elephantiasis:
Tropical disease
120 million infected, with about 40 million permanently incapacitated
-initial infection usually in childhood
-filarial worms (nematodes) from mosquitoes
Defense against pathogens:
physical barriers
chemical barriers
behavioral barriers
Physical barriers:
skin
nasal hairs
mucous linings
ciliated epithelium
Chemical barriers:
lysozyme
acidity
lactoferrin
Behavioral barriers:
sneezing
coughing
washing
If the 1st layer of defense fails:
the internal immune response takes over
The immune system does not constitute a traditional :
"organ system"
The immune system is primarily composed of:
a diverse collection of cells found in:
blood, lymph, and tissue throughout the body
Types of leukocytes:
Basophils/Mast cells
Eosinophils
Neutrophils
Monocytes/Macrophages
Lymphocytes
Plasma cells
Dendritic Cells
Basophils and Mast Cells function is:
release chemicals that mediate inflammation and allergic responses
Function of Eosinophils:
Destroy invaders, particularly antibody coated parasites.
Function of Neutrophils:
Ingest and destroy invaders
BLOOD
Function of monocytes and macrophages:
ingest and destroy invaders. Antigen presentation.
TISSUES
Function of lymphocytes and plasma cells:
specific responses to invaders, including antibody production
Function of dendritic cells:
recognize pathogens and activate other immune cells by antigen presentation
What leukocytes are found most in lymphoid tissue?
Lymphocytes and Plasma Cells
Lymphocytes and Plasma cells subtypes:
B lymphocytes
T lymphocytes
Natural killer cells
B lymphocytes:
Plasma cells
Memory cells
---> Bone marrow, plasma & membrane cells, antibody production
T lymphocytes:
Cytotoxic T Cells
Helper T cells
--> thymus gland. regulation or intracellular immunity
Natural Killer Cells:
bone marrow, intracellular immunity, tumors
The lymphatic system:
-Passive flow
-One-way valves
-Returns to venous circulation at right and left lymph ducts
Primary lymphoid tissues:
1. Thymus gland
2. Bone Marrow
Secondary lymphoid tissues:
1. Encapsulated:spleen & lymph nodes
2. Unencapsulated: GALT, tonsils
Lymph node:
Immune system diagram:
Two general types of immune response:
Innate (non-specific) immunity
Acquired (specific) immunity
Innate immunity:
non-specific
-Present from birth; general defense against pathogens
-protects against foreign substances or cells without recognizing specific identities
Acquired immunity:
specific immunity
-Body recognized particular pathogen and selectively reacts to it.
Active immunity:
body exposed to pathogen; creates own antibodies
Passive immunity:
acquire antibodies made by another organism
ex: shots, maternal antibodies
Innate immune responses uses ________ too bring pathogens into immune cells.
phagocytosis
Phagocytes:
macrophages, neutrophils
More phagocytosis:
Another mechanism of Innate immune responses is:
inflammation
3 functions of inflammation:
1. attract immune cells
2. produce physical barrier
3. promote tissue repair
Inflammation is initiated by:
cytokines
cytokines:
immune system messengers that cause inflammation
Produced by _________ from basophils and mast cells:
histamine
This opens ___________, which are useful for fighting infection.
capillary pores
unfortunate consequence of allergies.
3 stages of acquired immunity:
1. recognition of an antigen my lymphocytes
2. lymphocyte activation and proliferation
3. attacks on antigen-bearing bodies by activated lymphocytes and their secretions
Exposure to an antigen triggers ____________ and the immune response.
clonal expansion
You are born with A LOT of different:
pathogen-specific B-lymphocytes
First infection causes:
clonal expansion of B cells
Effector cells:
(plasma cells) fight infection and are short lived
Memory cells:
long-lived and produce secondary response
Immune response to future infections can be activated:
quickly
Secondary immune response:
Is the flu shot active or passive?
ACTIVE
Primary vs. Secondary:
Antibody:
works against foreign bodies by biding to antigens
also called immunoglobulin
Antbodies are proteins produced by _________.
B lymphocytes
Antibodes can be:
1. inserted into their cell membranes
2. released from the cell
5 classes of antibodies:
IgG
IgA
IgE
IgM
IgD
IgG:
comprise 75% of antibodies found in blood plasma; made in secondary immune response; cross placenta
IgA:
Found in external secretions
e.g. saliva, tears, breast milk
IgE:
gut parasites, allergic responses; can cause histamine release
IgM
Involved in primary immune responses & blood group antigens
IgD:
associated with IgM's but role unclear
Structurally antibodies look the same but:
molecularly they will be different.
An antibody molecule is composed of:
two identical light chains and two identical heavy chains, linked by disulfide bonds
What determines what type of antibody it is?
the base, part that is inserted into membrane
Where are the binding sites?
at the tips of the Y, which are the components that interact with the antigen or potential pathogen.
Antibodies are ________, which gives flexibility for binding to potential binding sites.
hinged
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