Ch 21: Immune System Flashcards
The Immune System protects our bodies from…
microbes that cause infection and disease.
What are the “three lines of defense” of the Immune System?
- Exterior Barrier
- Innate Immune System
- Adaptive Immune System
What is the External Border of the Immune System?
The skin
The skin of made of _______, the top layer of which contains…
stratified squamous cells
dead keratinized cells
_______ makes the skin impentrible to microbes.
Keratin
The skin is _______ and contains no _______ for microbes to feed upon.
dry, nutrients
The skin has _______ and _______ glands which secrete _______ and ________ which creates an acid mantle on the skin.
sweat glands, sebaceous
sweat, oils
The acid mantle is an _______ that _______ microbes.
anti-bacterial, kills
The skin secretes what two anti-bacterial proteins?
- Dermacidis
- Defensin
What are the four main openings of the skin?
- Mouth
- Ears
- Urethra
- Anus
What is the purpose of mucus?
To capture micro-organisms
Tears, saliva, and mucus contain an enzyme called _______.
Lysozyme
What does lysozyme do?
breaks down cell walls
We are born with our ________ Immune System.
Innate
What are four characteristics to keep in mind with the Innate Immune System?
- It is more primitive (part of our evolution)
- Comes into play if the External Barrier is breached (through puncture or oriface)
- Generally local
- Supports the Addaptive Immune System
What are the five types of Leukocytes standing by to be used by the Innate Immune System?
- Neutrophils
- Eosinophils
- Basophils
- Lymphocytes
- Monocytes
Innate Immune System
Neutrophils are waiting in _______ to engulf microbes.
Connective tissue
Innate Immune System
Eosinophils are found in…
mucus membranes
Innate Immune System
Basophils secrete what two chemical messages and what are their functions?
- Interleukins, stimulates activation and creation of more WBCs
- Histamines, relate to inflamation
Innate Immune System
Lymphocytes are also known as _______.
Natural Killer Cells
What is the job of natural killer cells?
to patrol tissues and kill cells marked for destruction
Innate Immune System
Monocytes are also known as _______ and are _______.
Macrophages, phagocytotic
_______ work with the leukocytes to inititate the immune response.
anti-microbial proteins
What are the two types of anti-microbial proteins?
- Interferons
- Complement System
Interferons consist of…
anti-viral and anti-cancer proteins
The complement system consists of…
30 different proteins
The complement system aids…
both innate and adaptive immunity.
The complement system can cause what four things to occur?
- Inflamation
- Immune clearance
- Phagocytosis
- Cytolysis
The complement system
What is meant by “immune clearance”?
Proteins attach to smaller undetectable microbes to aid system to tag for destruction
In the complement system, phagocytosis is triggered by the process of
opsonization
Opsonization is the…
coating of a particle/microbe with proteins to target it for phagocytosis.
Cytolysis, occurs when a cell…
bursts due to an osmotic imbalance that has caused excess water to diffuse into the cell.
Inflammation is triggered by the _______ Immune System.
Innate
Inflammation is indicated by…
red, swollen, painful tissue
inflammation is the result of an abundance of ________ at the site of an injury/infection.
white blood cells
In inflammation, basophils will secrete _______.
Histamines
Histamine release by basophils trigger _______ which ________ blood flow and initiates ________.
vasodilation, increase, inflammation
When a histamine triggers inflamation, what occurs?
- increased blood flow to area
- produces reddish skin
- fluid builds up
- brings more white cells to area
Endogenous pyrogens initiate _______.
fever
A fever is…
an increase of body temperature
Endogenous pyrogens are toxic to _______.
microbes
The Adaptive Immune System is not local but _______.
systemic
Systemic means the entire…
body is involved.
True or False
We are born with adaptive immunity.
False
Acquiring adaptive immunity requires _______.
Exposure
The adaptive immune system exhibits _______, which means that the immune system responds to a _______.
specificity
specific thing
What are the three components of the adaptive immune system?
- Lymphocytes
- Antigens
- Antibodies
Lymphocytes have continuous cell surface _______ that bind to specific _______.
receptors, antigens
Antigens bind to
specific lymphocyte receptors
Antibodies bind to
specific antigens
What is an antibody?
A blood protein produced in response to and counteracting a specific antigen.
Antibodies combine chemically with substances which the body recognizes as _______, such as _______, _______, and foreign substances in the _______.
alien, bacteria, viruses, blood
What is an antigen?
A toxin or other foreign substance which induces an immune response in the body, especially the production of antibodies.
Antibodies circulate in the blood looking for _______.
Antigens
This structure represents an
antibody
The red portions are called the
light chain
The blue part is called the
heavy chain
The top “Y” portion is called the
variable region
The bottom main trunk of the “Y” is called the
constant region
What are the characteristics of the variable region of an antibody?
- It is different in every lymphocyte
- It is the part that binds to the antigen
What are the two types of Lymphocytes?
B-lymphocytes
T-lymphocytes
Lymphocytes are produced from _______ in _______.
homopoietic stem cells, bone marrow
Lymphocytes that have matured but not yet received their antigens are called…
naive lymphocytes
Where does each type of lymphocyte mature?
B-cells mature in bone
T-cells mature in thymus
What are the characteristics of a Naive lymphocyte
- They are fully mature
- Have not received their antigens yet (they don’t know their purpose of being)
Naive lymphocytes receive their antigens from
secondary lymphatic organs
What are some secondary lymphatic organs?
- Lymph nodes
- Tonsils
- Spleen
What are the primary lymphatic organs?
- Bone marrow
- Thymus
(Where the B & T cells mature)
When T-cells mature, the must first pass through the _______ of the thymus to undergo ________.
cortex, positive selection
In positive selection, the receptors of lymphocytes are checked for _______.
Explain what that means.
- immunocompetence
- ability to bind to antigens
What happens to a lymphocyte that fails positive selection?
it is tagged for apoptosis
What happens to a lymphocyte that passes positive selection?
It passes through the cortex to medulla of the thymus for negative selection.
In negative selection, lymphocytes are checked for
“self” antigens (if will it bind to cells the body needs)
The ability of the body to deal with a certain amount of lymphocytes that may attach to cells the body needs is called
tolerance
What happens to lymphocytes that fail negative selection?
Tagged for apoptosis
What happens to a lymphocyte that passes negative selection?
It is released to pick up its antigen from secondary lymphatic organs
The process of positive and negative selection results in a
mature lymphocyte
True or False
Naive lymphocytes have been activated.
False
B-cells go through negative and positive selection _______ in _______.
locally, bone marrow
T-cells go through negative and positive selection in
the thymus
True or False
T-cells traveling from bone marrow to the thymus are mature.
False
The binding of a lymphocyte to an antigen is called
activation
T-cell receptor binding requires an
Antigen Presenting Cell (APC)
What kind of cells can be APCs?
neutrophils, b-cells
What is MHC?
Major Histocompatibility complex
A group of genes found on the surfaces of cells that help the immune system recognize foreign substances.
How are APCs created?
- a neutrophil or b-cell finds an antigen
- engulfs antigen
- presents that antigen on its surface along with MHC
- MHC+Antigen then bind to t-cell receptor
Once a t-cell is activated, it initates
cell mediated immunity
Cell mediated immunity is when a specific t-cell…
proliferates and differentiates
What is t-cell proliferation and differentiation also known as?
Colonal selection
What are the four types of t-cells
- Cytotoxic
- Helper
- Regulatory
- Memory
What do cytotoxic t-cells do?
attack targeted cells
What do helper t-cells do?
secrete interleukins
What do regulatory t-cells do?
Inhibit T-cell proliferation after the infection
What do memory t-cells do?
Remain in system after infection
What two types of t-cells make up the Primary Response of immunity?
- Helper
- Cytotoxic
What are the characteristics of helper t-cells?
- bind to antigen
- secrete interleukins
- attract neutrophils
- attract macrophage
- stimulate b & t cell production
What are the characteristics of cytotoxic t-cells?
- binds to antigen
- is the “leathal hit”
- releases chemicals to kill cell
What are the characteristics of a memory t or b-cell?
- remain after infection
- reinfection will be fought more quickly due to exposure and produces secondary response
What are the characteristics of B-cell activation?
- b-cell receptors bind to antigen
- b-cells engulf antigen and present it on surface
B-cell activation requires…
interleukins secreted by helper t-cells
Humoral immunity refers to what type of lymphocyte?
B-cell
Explain b-cell:
Proliferation
Differentiation
proliferation: the b-cell is making copies itself
differentiation: it is dividing specifically into memory cells and antibody producing plasma cells
In a humoral immunity response, what is recognition?
- b-cells bind to an antigen
- the bound b-cells activate helper t-cells
In a humoral immunity response, the attack comes from
Antibodies in blood stream
In a humoral immunity attack, neutralization occurs when
antibodies bind to and disable antigens
In a humoral immunity attack, what is complement fixation?
Complements bind/puncture antigen causing inflamation leading to apoptosis (bursting)
In a humoral immunity attack, agglutination occurs when
Many antibodies bind to antigen causing clumping
In a humoral immunity attack, precipitation is when
The antigen/antibody complex (from agglutination) becomes too big (forming molecules) and falls out of solution.
What are the five steps of a humoral immune attack?
- Antibody attack
- Neutralization
- Complement fixation
- Agglutination
- Precipitation
What are 3 possible immune system disorders?
- Hypersensitivity
- Autoimmune diseases
- Immunodifficiency diseases
Immune Disorders:
Hypersensitivity is an
overactive immune system
Immune Disorders:
How many types of hypersensitivity disorders are there and what are they called?
4,
Type 1, Type 2, Type 3, Type 4
Immune Disorders:
What are the characteristics of Type 1 Hypersensitivity?
- Deals with Allergies
- Mediated by IgE antibody
- Allergens bind to IgE and cause a release of histamines
- Released histamines cause inflammation and allergic response
Immune Disorders:
What are the characteristics of Type 2 Hypersensitivity?
- Antibody mediated cytotoxic resonse
- Antigen on cell binds to antibody and marks cell to be destroyed
- This is seen in transplant rejections
Immune Disorders:
What are the characteristics of Type 3 Hypersensitivity?
- antigen-antibody complex is found in blood stream
- causes clots that lead to tissue damage
- nephritis is an example in which causes blockage in the kidneys and kills them
Immune Disorders:
What are the characteristics of Type 4 Hypersensitivity?
- cell mediated immune response
- t-cell (instead of antibody) binds to antigen
- can cause inflammation (anaphalactic shock) that leads to death
- is a delayed reaction as the t-cell process takes longer than antigen/antibody process
Immune Disorders:
What are the characteristics of autoimmune diseases?
- Failure of body to tolerate “self”
- Initiates immune response against own tissues
Immune Disorders:
Give two examples of tissue specific autoimmune disorder
- Multiple Sclerosis
- Rheumatoid Arthritis
Immune Disorders:
What occurs in a systemic autoimmune disease?
Give an example
- The body attacks molecules (as opposed to cells)
- SLE (systemic lupus erythematosus) attacks DNA
Immune Disorders:
What are two kinds of immunodifficiency disorders?
- SCID (Severe Combined ImmunoDifficiency)
- AIDS (Acquired Immunodifficency Disorder)
Immune Disorders:
What happens to a person with SCID
Their body does not produce B-cells or T-cells
Immune Disorders:
What are the characteristics of AIDS?
- Infection comes from HIV (Human Immunodifficency Virus)
- HIV’s host cells are T-cells (HIV attaches and enters T-cells to reproduce)
- HIV basically kills off t-cells and thus the immune system
