Immune System Flashcards
Name the 6 Lymphoid organs
Lymph nodes, tonsils, MALTs, spleen, thymus, bone marrow
What does MALT stand for?
Mucuous-associated lymphoid tissue
What is immunity?
Resistance to disease
What two immune systems does the body have?
Innate and Aquired
This system includes physical barriers, phagocytes, complement proteins
The Innate
This system includes antibody production, cytokine production, and cell-mediated apoptosis
Acquired
Part of the 1st Line of Defense, includes tears, mucus membranes, and the skin
Barriers
What is the 2nd line of defense
Cells and chemicals in the innate system. Includes phagocytes, Natural Killer (NK) Cells, antimicrobial proteins (such as interferons and complements) and fever
Proteins produced by an infected cell that cause neighboring cells to produce antiviral proteins
Interferons
A pathogen that uses receptor-mediates endocytosis to enter a cell then hijacks ribosoma machinery
Viruses
What is agglutination?
The term for when erythrocytes get bound up with antibodies
What two types of molecules can bind to an invader or an incorrect ABO cell type to help macrophages consume them?
Toll-like receptors & Opsonin
What is the the technical name for the immune process that helps the body identify and destroy harmful parasites by binding to them
Opsonization
What is the key immune cell that helps prevent microbes getting past the epidermis?
Macrophages
The protein filament that prevents microbes getting past the epidermis
Keratin
Where do T cells typically get activated?
Secondary Lymph Organs (the spleen, lymph)
What cells activate T cells?
Macrophages and Dendritic Cells
What activates T cells
Binding with antigen-presenting cells (APC)
What typically activates B Cells?
Helper T Cells
What macrophage secretion raises body temperature at the hypothalamus to create fever?
Pyrogens
If a cell lacks MHCs what kind of cell might kill them?
Natural Killer Cells
The name for migration activity by a neutrophil, eg, when it is motivated to move toward the area of an injury
Chemotaxis
The temporary binding and unbinding to sticky endothelial cells adhesion molecules
Margination
The process of a cell entering injured or infected tissue from the capillary
Diapedesis
Proteins responsible for displaying antigens to immune cells
Major Histocompatibility Complex (MHCs)
The process by which antibodies block all binding sites on a virus or harmful toxin
Neutralization
The proteins secreted by plasma B Cells
Antibodies aka Immunoglobulins
Antibodies that react to specific surface antigens on red blood cells
IgM
The clumping of RBCs that occurs when incompatible blood is mixed
Agglutination
An elevated level of neutrophils in the blood might indicate infection with what?
Microorganisms (bacteria & fungi)
These cells do not recognize cancer cells or abnormal cells by their antigen but rather by the absence of the self antigen
Natural Killer Cells
A group of 20 plasma proteins that circulate in the blood in an inactive state
Complement proteins
When activated MAC lyse micros using the cell membrane to do what?
Form pores, mark cells for phagocytosis, promote inflammation
Microbial proteins that interfere with viral replication
Interferons
What kind of cell mediates the humoral response?
B Cells
What are the two types of B Cells?
Plasma Cells, which produce antibodies
Memory Cells
The cellular immune response is mediated by what type of cell?
T Cells
What are the two types of T Cells?
Cytotoxic T Cells
Helper T Cells
What kind of cells are able to bind with antigens on cell membranes to then produce perforins and granzymes?
Cytotoxic T Cells
What cells punch holes in the cell membranes of microorganisms
Perforins
What kind if cells induce apoptosis?
Granzymes
This kind of immunity involves antibodies passed from one person to another
Humoral
This kind of immunity involves an intracellular pathogen such as a virus
Cell Mediated
These cells have already been activated by an antigen and are primed and ready for action during primary response
Memory B Cells
What is the specific part of the antigen that the antibody or lymphocyte receptor binds to
Antigenic determinant or epitope
What kind of cells do T cells activate?
B Cells and Cytotoxic Cells
Name an autoimmune disease and the tissue it targets
Multiple sclerosis, the myelin sheath of axons
Where does the Rh in Rh antibody come from?
Rhesus monkeys
True or False: If a cell posses a particular ABO Antigen the plasma will have the corresponding antibody
False, they will have the opposite
When does blood obtain Rh antibodies
After being exposed to Rh+ blood
What blood type is the universal recipient?
AB+
What blood type is the universal donor?
O -, because it lacks A, B, and Rh surface antigens.
A woman has agglutination with anti-B and anti-Rh antibody, what is her blood type?
A+
What is an antigen?
Any substance capable of provoking an immune response
True or False: The two immune systems are completely separate
False. They are interconnected and interdependent
What are the characteristics of the innate immunity?
Non-specific, localized, short-lived
What are the characteristics of acquired immunity?
Specific, systemic, take time, long lasting
What substances is keratin resistant to?
Weak acids and bases, bacterial enzymes, toxins thanks to protective substances: lipids in sebum, skin acidity, dermicidin in sweat
What part if the first line of defense is negatively affected by smoking?
One-way cilia of the upper respiratory tract are destroyed
What does a cell become after it engulfs a bacteria?
A vessicle
What triggers a macrophage to phagocytize something?
Toll-Like Receptors
What is inflammation? What are its signs?
A triggered response to to physical injury or infection. Characterized by redness, pain, swelling, and heat
Why is inflammation helpful to the body?
Localized vasodilation and hyperemia (heat) increases metabolism and allows chemical reactions to occur faster. Capillaries become leaky, allowing for rapid leukocytosis
What is the benefits of pain?
Increased awareness of and therefore protection of an area
What are the three steps of leukocytosis?
- Neutrophils enter the blood from bone marrow
- Margination: Neutrophils cling to capillary wall
- Diapedesis: Neutrophils flatten, squeeze out and walk on pseudopods
What releases antimicrobial proteins (interferons and complements)
Macrophages and Neutrophils
Where do B lymphocytes become immunocompetent?
Bone marrow
What is negative/positive selection?
In the thymus T cells that are anti-self are eliminated and T cels with a weak response to self-antigens are selected
What is the difference between B and T Cells in the kinds of cells they attack?
B - Extracellular
T - Intracellular
What does “immunocompetent” mean?
The capacity to produce a normal immune response and bind to a specific antigen
What is the first part of the humoral immune response?
Antigen challenge: an antigen and a naive lymphocyte encounter for the first time, usually in a secondary lymph organ.
What happens when a B cell matches its antigen?
Clonal selection (make a bunch more) and most become plasma cells to make antibodies. Some become memory cells and live in the body for second exposure
What is the shape of an antibody?
Y-shapes proteins with variable regions at the tip of each arm that bind to specific targets and no other determanents
IgM
Pentamer (5-Ys), first antibody released
Potent agglutinator. Activates complement proteins
IgA
aka” secretory immunoglobulin”: not found in plasma, found in mucus and secretions
Monomer or Dimer
Exists in semen and intestines, but not blood
Helps prevent entry of pathogens
IgD
Monomer attached to the surface of B cells
Functions as B cell receptor
IgG
Monomer
70-80% of all antibodies in plasma
Secondary and late reaponses
Can cross placental barrier
IgE
Monomer
Active in some allergies, parasites
Causes Mast cells and basophils to release histamine
Causes hypersensitivities
Membrane Attack Complex
Binding to and lysing of a cell by complement proteins
What is the clumping of antigens called?
Precipitation
What is the primary immune response?
Cellular differentiation and proliferation; occurs after first exposure to an antigen
humoral AND intercellular
How long does it rake plasma antibody levels to peak
10 days after a lag period of 3-6 days
What happens during the secondary immune response?
Memory cells respond within hours, levels peak in 2-3 days. Antibodies remain much longer (weeks or months)
What is artificial active immunity?
Vaccination
What is artificial passive immunity?
Injection of immunoglobulin serums
What is hypersensitivity?
An abnormal, vigorous (overactive) immune response to a perceived threat that is otherwise harmless
What is the difference between immunities for hypersensitivies?
Antibodies (humoral) cause immediate, subacute hypersensitivities
T Cells cause delayed hypersensitivity
Describe Type 1 Allergic Reactions (Allergic)
Allergies & Asthma
Occurs within seconds-30 minutes
IgE attaches to Mast cells
Mast cells release histamine
Histamine causes inflammation and itching
Body release leukotrine aka “slow reactive substance”
Leukotrine causes smooth muscle contractions in airways
Treat with anti-histamines, leukotriene blockers
Describe Anaphylactic Shock (Type 1 Allergic Reaction)
Systemic Reaction, life-threatening
Allergen enters the blood (like via bee sting)
-Constriction of bronchioles
-Sudden vasodilation in all tissues
-Increased capillary permeability (fluid loss)
-Hypotensive shock (low BP)
Treat with epinephrine
What causes Subacute Hypersensitivities?
IgM and IgG transferred from blood plasma or serum
What is a Type 2 Allergic Reaction?
Cytotoxic
Antibodies bind to antigens in specific body cells, stimulating phagocytosis and complement-mediated lysis
Happens from mismatched blood transfusions
What is a Type 3 Allergic Reaction?
Immune Complex Hypersensitivity
Ex. Lupus
Antigens are widely distributed throughout the blood
Insoluble agglutinations form
Causes inflammation, cell lysis, death
What is a Type 4 Allergic Reaction?
Delayed Hypersensitivity
Ex. Poison Ivy/Oak
Cytokines activate macrophages and cytotoxic T cells
What is immunodeficiency?
Low production or abnormal function of immune cells
What are two examples of immunodeficiencies?
SCID - Severe Combined Imm. Disease (Bubble Boy)
AIDS - Acquired Immun. Syndrome
What does HIV target?
Helper T Cells
What is an autoimmune disease?
The immune system fails to distinguish between self and non-self
What are the 4 different types of Organ Transplants?
Autograft: from self
Isograft: from twin
Allograft: other people (not twins)
Xenograft: Animals
What do we use to help prevent a graft from being rejectes?
Corticosteroid drugs that suppress the inflammatory response AND antiproliferatice drugs (chemo drugs! severe side effects)
