Chapter 51 - The Immune System Flashcards
Two level of defense in vertebrates
- Innate Immunity
2. Adaptive Immunity
- Recognition of invading pathogens
- Rapid response
- Uses soluble antimicrobial proteins
Innate Immunity
- Characterized by genetic rearrangements that generate a diverse set of molecules to recognize any invader
- Slower response buy highly specific
Adaptive Immunity
Four potential routes of infection
- Skin
- Digestive
- Respiratory
- Urogenital
All routes of infection are lined with what?
Epithelial Cells
Largest organ in the body
Skin
Two layers of the skin
Epidermis and Dermis
- Five Layers (10-30 cells thick)
- Contains Keratin
- Oil and Sweat glads give a pH of 3-5
- Lysozymes
Epidermis
Makes skin tough and water resistant
Keratin
Break bacterial cell walls
Lysozymes
- Contains two layers of connective tissue and is 15-40 times thicker than epidermis
- Provides structural support for epidermis, and matrix for blood vessels, muscles and nerve endings
Dermis
What is the job of the dermis?
Provides structural support for epidermis, and matrix for blood vessels, muscles and nerve endings
Layer beneath the skin
Subcutaneous Layer
Subcutaneous layer’s contain mainly __________ cells
Adipose (fat)
The job of the subcutaneous layer
Acts as shock absorber and insulators
The digestive, respiratory and urogenital tracts are lined by _______________
Mucous Membranes
- Epithelial tissue
- Secrete mucus which traps microbes
Mucous Membranes
Three defenses in mucosal surfaces
- Salivary lysozyme; acidic stomach
- Cilliary action to move mucus
- Acidic urine
Recognizes chemical patterns characteristic of invaders
Innate Immunity
Two different kinds of innate immunity
- TRL
2. MBL
Are found within or on the cell surface of pathogens
TRL (Toll Like Receptors)
Are given off by pathogens and are found in the fluids they are in
MBL (Mannose Binding Lectins)
Another name for white blood cells
Leukocytes
Three types of white blood cells that are directly involved in innate immunity
- Macrophages
- Neutrophils
- NK lymphocytes
Three characteristics of neutrophils
- The most abundant circulating leukocytes
- First to appear at site of damage/infection
- Kill microbes by phagocytosis
Three characteristics of macrophages
- Large, irregularly shaped cells
- Enter tissues from the blood, and can remain in connective tissue indefinitely
- Kill microbes by phagocytosis
Three characteristics of NK Lymphocytes
- Destroy virus-infected cells and cancer cells
- Inject chemicals that result in apoptosis
- Marcophages then eat the remains
Cell performing programmed cell death
Apoptosis
Can induce or increase an innate response
Inflammatory Response
The two steps in inflammatory response
- Injured cells release chemical alarms (histamine, prostaglandins)
- Cause nearby blood vessels to dilate and increase in permeability
Signs of inflammatory response
- Redness
- Warmth
- Swelling
- Pain
Inflammatory response promote ________ and ______ accumulation
- Leukocyte
- Fibroblast
Inflammation is reduced when what happens?
Tissues begin to heal
Is the primary chemical to induce a widespread immune response
Histamine
The cell primarily responsible for the production of histamine is a leukocyte called a ____________
Mast Cell
Histamines and Mast Cells are apart of what kind of response?
Inflammatory Response
The process of the compliment system
- 30 different proteins that circulate in the blood in an inactive form
- Becomes activated when TRLs or MBLs are detected
- Proteins aggregate to form a Membrane Attack Complex on surface of pathogens…or make a pore
- Pathogens swells and burts
Proteins aggregate to form a _______________ on surface of pathogens…or make a pore
Membrane Attack Complex (MAC)
The scientific study of immunity began with who and when?
Edward Jenner in 1796
How did Edward Jenner invent the vaccine?
- Observed that milkmaids who had cowpox (mild) rarely experienced smallpox (severe)
- Jenner inoculated individuals with fluid from cowpox vesicles to protect them from smallpox
- First vaccination
The four characteristics of the specific, or adaptive, immune response are
- Specificity
- Diversity
- Memory
- Ability to distinguish self from non-self
A molecule that provokes a specific immune response
Antigens
What is found on the surface of antigen cells?
Proteins and Glycoproteins
Leukocytes with surface receptors for antigens
B and T Lymphocytes
Generally, what do B and T Lymphocytes do?
Direct an immune response against either the antigen or the cells that carries it
When a B or T lymphocyte binds to a specific antigen for the first time, it activates ___________
Clonal Selection
What process produces clones?
Clonal Selection
Two things can happen when clones are produced?
- Respond immediately
2. Memory cells
Where do the B Lymphocytes mature?
In the bone marrow
B Lymphocytes respond to antigens by secreting _________ or____________
- Immunoglobulins (Ig)
or - Antibodies
The process of producing immunoglobins
Humoral Immunity
What are the four steps in humoral immunity?
- Naive B cells in secondary lymph organs
- Activation results in clonal expansion
- B cells produce soluble Igs to be circulated
- Once they do this they are known as plasma cells
One B cells produce soluble Igs to be circulated, they are called _________
Plasma Cells
Another name for Immunoglobulins
Antibodies
What to Immunoglobulins consist of?
Y-shaped molecules
Each chain of immunoglobulins has what special part?
Antigen-binding site
Each Ig can bind two identical antigents. This causes the following process.
- Allows formation of antigen-antibody complexes
- These can allow macrophages to better identify invaders
- Igs will also bond to mast cells to produce histamine
How man classes of immunoglobulins are there?
Five
When are immunoglobulins released and how are they composed?
- Released at different times
- All have different compositions
Where do T Lymphocytes mature?
In the thymus
What is the job of T Lymphocytes?
Directly attack cells that carry specific antigens
What kind of cells do T Lymphocytes attack?
Usually virally infected or cancerous cells
The name of the process of T Lymphocytes attacking antigens?
Cell-mediated immunity
The three steps in Cell Mediated Immunity?
- A marcrophage ingests virus or cancer cell and presents the antigen
- T cells are activated upon through antigen recognition
- Clonal expansion occurs
Cell mediated immunity produces what two types of activated cells?
- Cytotoxic T
2. Helper T
Cells that actually attack the cells with foreign antigens right away
Cytotoxic T Cells
Cells that detect antigens, and release cytokines.
Helper T Cells
What do cytokines do in helping Helper T Cells?
They cause the growth of more T cells
Two different kinds of organs in the immune system
- Primary lymphoid organs
2. Secondary lymphoid organs
- Where cells grow and mature
- Bone marrow and thymus
Primary lymphoid organs
- Cells move here to expose themselves to antigens
- Lymph nodes, spleen, and mucosal-associated lymphoid tissue (MALT)
Secondary lymphoid organs
What organs are apart of the secondary lymphoid organs?
- Lymph nodes
- Spleen
- MALT
What is the site of B cell maturation?
Bone marrow
What is the site of T cell maturation?
Thymus
Any lymphocytes that bind to ________ undergo ________
- Self-anitgens
- Apoptosis
If the cell is prone to attack your own antigens what will happen?
Apoptosis
What does apoptosis eliminate?
Autoimmunity
The locations of these organs promote the filtering of antigens that enter any part of an individual’s body
Secondary Lymphoid Organs
Where do B and T cells become activated?
Lymph Nodes
What is the site of immune responses to antigens found mainly in the blood?
Spleen
What includes the tonsils and appendix?
MALT (Mucosal-associated lymphoid tissues)
What is a primary immune response?
When a person is first exposed to an antigen, it takes time for the B and T lymphocytes to differentiate and for clonal expansion to occur.
What does the primary immune response cause?
Gives the pathogen time to cause illness
During clonal expansion, certain cells do not fight the infection, but instead just go into the lymphoid system.
Memory Cells
Where do memory cells go?
Lymphoid system
- There is a large collection of memory cells that can recognize the antigen
- Immune response is more effective
- Illness rarely occurs
Secondary immune response
The acceptance of self cells is known as _______
Immune tolerance
These are caused by the failure of immune tolerance
Autoimmune Deseases
What do autoimmune diseases result in?
The activation of autoreactive T-cells, and the production of autoantibodies by B cells
What harms do autoimmune diseases cause?
- Inflammation
- Organ dammage
________ refer to a greatly heightened response to a foreign antigen, or allergen
Allergy
The most common type of allergies in known as _____
Immediate Hypersensitivity
What does Immediate Hypersensitivity result in?
- Hives
- Local responses
For allergies, this is dramatic, systemic response.
Anaphylaxis
What can happen in Anaphylaxis is not treated?
Death….duh duh duhhhh
Antigen types are actually ______
Blood types
_______ cell membranes have surface antigens
Red blood cells
RBC cells membranes have surface antigens that are usually ______ or _________
- Glycoproteins
- Glycolipids
What are used to determine blood type?
A, B, and Rh
What are genetically determined?
Blood types
People may have what kind of blood types?
A, B, AB, or nothing (O)
You automatically produce antibodies if what happens?
If foreign antigens are introduced into your blood stream, you will produce antibodies to destroy them.
What can pathogens do to avoid immune system detection?
Alter their surface antigens
Influenza virus expresses two surface proteins ________ and _________
- Antigenic drift
2. Antigenic shift
The accumulation of point mutations to the viral genome that express antigen
Antigenic drift
Sudden appearance of new viral sub type where proteins are completely different due to antigenic drift
Antigenic shift
Mounts a direct attack on Helper T cells
HIV (Human immunodeficiency Virus)
What does HIV do?
Binds to CD4 proteins on T cells, and is endocyosed
An individual is considered to have AIDS when
their T cells level has dropped significantly
What does immunosuppresion results in (from AIDS)
An increase in opportunistic infections and cancers
