Test #1 (Immune System, Infectious Disease and a taste of CV) Flashcards
The body system that defends against foreign invaders.
The immune system
Problems such as allergies and hypersensitivities arise when the response to an invader is ___________
Excessive
When the body’s own tissue is perceived as foreign or dangerous.
Auto-immunity
A type of microorganism that is too small to see with the unaided eye; ex. bacteria, viruses, fungi.
Microbe
A microbe that causes disease.
Pathogen
A substance that tends to kill or damage microbes – ex. lysosomal enzymes released by immune cells.
Anti-microbial substance
Large molecules (usually proteins or polysaccharides) on cell surfaces that elicit specific responses from hosts.
Antigen
T/F: Antigens are always on foreign-cells
False: Antigens can be on self-cells and foreign-cells
A specific, discrete component of an antigen that is used as an identifier and binding site by host immune cells.
Epitope
A protein in the immune system that is responsible for binding to an epitope and initiating the destruction of the associated organism.
Antibody
The immune system has two responses. Can you name them???
- The innate response
2. The adaptive response
The _____ ________ is something that we are born with. It is our non-specific initial line of defence.
Innate response.
Which of the following is untrue of the innate immune response:
• It’s a rapid, early response
• It’s always the same (non-specific)
• It’s made in Santa’s workshop
• It primarily reacts to microbes
• It relies on phagocytes and antimicrobials
• It includes external physical barriers like the skin and mucous membranes
• It’s fairly easy for microbes to adapt to it
• It stimulates adaptive responses
It’s made in Santa’s workshop
The first line of defence is the ____ and our ____ _________.
The skin and our mucous membranes.
_____ on the skin forms a protective film that inhibits the growth of certain microbes.
Sebum
______ can trap microbes which can be then expectorated or sneezed out of the body.
Mucous
Tears and saliva contain ________, an enzyme that breaks down the cell wall of some bacteria.
Lysozyme
The ______ ____ __ ______, or internal defences consists of antimicrobial substances, natural killer (NK) cells, and phagocytes. It involves activation of the complement system.
The second line of defence.
____________ substances include interferons, iron binding proteins, and antimicrobial proteins.
Antimicrobrial
This is a specific response. It develops with exposure to various organisms and substances.
The Adaptive Response
Which of the following statements about the adaptive response is untrue:
• It’s slower to kick in and develops in response to specific attributes of an invader
• It works with the innate response system to enhance reactivity
• It attacks microbes and antigens
• It attacks elves and friendly reindeer
• It generates immunologic memory, meaning that subsequent exposures lead to a more rapid response
It attacks elves and friendly reindeer
The primary cells of adaptive immunity are _____________, and _______________.
B-Lymphocytes (B-cells), and T-Lymphocytes (T-cells).
Lymphocytes act as __________ cells, which assist in controlling and orchestration of the immune response (ie. by activating other cells).
Regulator
Lymphocytes also act as __________ cells, by killing and eliminating the microbe or antigen.
Effector
_________ cells are phagocytes (macrophages, neutrophils, eosinophils) that kill or break apart an invader.
Accessory
________ cells present antigens and epitopes to killers.
Dendritic
There are always a high number of immune cells and other immune materials (like antibodies) circulating in the blood and lymph. This is known as _______ ________.
Humoral immunity.
Which of the following is not a place where Immune cells are found: • Lymph nodes • Bone marrow • Thymus • Tonsils • Spleen • Christmas presents • Skin • Mucosa • Vital organs
Christmas presents
_________ are key players in humoral immunity. They are very good at recognizing microbes and antigens (assisted by T-helper cells). They also produce antibodies.
B-Cells
When a B-cell binds to its associated _______, it becomes activated. Upon activation, it selects the type of clone needed: plasma cell or memory cell.
Antigen
When it reaches full maturation, ______ cells produce and secrete antibodies (aka immunoglobulins) designed for a specific antigen. Antibodies bind to epitopes and either kill or neutralize the invader, or present them to T-cells or macrophages.
Plasma
_______ cells do not participate in the initial immune response. They stay in the body to respond quickly if a secondary exposure to the same antigen occurs.
Memory
Which immunoglobulin is:
• The only Ig to cross the placenta (protects neonates) à passive immunity in newborn
• Diffuses readily out of the vascular zone into the tissues
• Antiviral, antitoxin, antibacterial actions
• Activates killer cells
• Activates the complement system
IgG
75% of antibodies are ____.
IgG
Which immunoglobulin is:
• Predominant in saliva, tears, nasal, GI, and respiratory secretions
• Found in breast milk (protects neonates)
• Blocks entry of organisms to the eyes, gut, respiratory, and urinary tracts
• Protects mucosa
IgA
Which immunoglobulin is: • Early responder • First Ig formed after immunization or initial exposure to a pathogen • Activates the complement system • Forms natural ABO antibodies • Doesn’t leave the blood or lymph
IgM
Which immunoglobulin is:
• Present in small amounts in serum
• Needed for B-cell maturation
IgD
Which immunoglobulin is: • Found in tiny amounts in plasma • Binds to mast cells and liberates histamine and other inflammatory substances • Attracts eosinophils • Responds to parasites
IgE
Cells that bind to and/or break down antigens. They present epitopes on their surfaces, or alter the antigen to make it more recognizable. B-cells, macrophages, and dendritic cells all act as presenting cells. Also, the antibodies can work in the same way.
Antigen Presenting Cells
_______ are responsible for what is called cell-mediated, or cellular immunity. They work via cell- to-cell contact or by secreting messenger compounds that communicate with immune system cells.
T-Cells
The key regulatory cells of the immune system. They release various T-messenger compounds that activate and regulate the activities of the other cell types. They activate B and T cells correctly depending on the type of immune challenge. Up-regulation.
T-Helper cells (a.k.a. CD-4 cells)
These suppress/modify immune responses. They decrease immune cell production. They control the mechanism to help ensure the response matches the situation, and that healthy self-cells are not killed. Down-regulation.
Regulatory T-cells (a.k.a. Tregs)
These destroy identified/presented antigens. They kill virus- infected cells by various means (lytic enzymes, cytotoxins, perforins, interferon). They are involved in attacking cellular problems that antibodies cannot influence.
T-cytotoxic cells (a.k.a. CD-8 cells)
In order for T-cells to recognize and respond to an antigen, it must be presented by another cell or an antibody. It must be coded by a ________ ________ _________.
Major Histocompatibility Complex (MHC)
MHC are a group of genes on chromosome 6 that determine tissue and blood compatibility. In humans, they are often called _____ _______ ________.
Human Leukocyte Antigens (HLA)
There are two classes of HLA. Class I are on ___ _____ ______. Class II are on ____ ________ _____.
Class I are on all cell surfaces.
Class II are on immune system cells.
HLA are key factors in determining self from ________
Non-self
Immunity that develops through direct exposure to an antigen and the in response, the immune system develops antibodies.
Active natural immunity
Immunity that develops when the body is purposefully introduced to an antigen and subsequently reacts by developing antibodies (ie. vaccines).
Active artificial immunity
Immunity that is passed from a mother to fetus, to protect the infant during the first few months of life as they develop their own immune system (ie. IgG crossing the placenta, IgA passed on in breast milk).
Passive immunity
Immunity wherein antibodies are injected from one system to another; used to help fight a current infection if the individual has not been immunized against the specific organism (ex. hepatitis B infections; rabies antiserum, snake antivenom)
Passive artificial immunity
The ability to distinguish between self- and non-self antigens.
Immunologic self- tolerance
The attacked body tissue may have similar characteristics to a microbe the immune system has just battled (ex. ________ _______). In this case, the foreign antigen is believed to be immunologically similar to auto-antigens (shares some of the same epitopes).
Rheumatic fever
Some HLA inheritance corresponds to activation of autoimmune disease. Exposure to a microbe or foreign material (like a breast implant) can initiate an autoimmune disease. Some examples would be:
Rheumatoid arthritis, ankylosing spondylitis, multiple sclerosis, and diabetes.
Sometimes there is an over response of immune activities. For instance, in _________ there is a hyper-reactivity of B-cells and an overproduction of antibodies. SLE may be triggered by a hyper reactivity to UV light.
SLE (lupus)
Sometimes there is a reduced T-cell suppressor response (ex. _________ ________ exacerbations are associated with drops in T-suppressor cell counts).
Multiple Sclerosis
In _________ __________, there is an autoimmune response to self-IgG. The resulting body is called rheumatoid factor.
Rheumatoid arthritis (RA)
Rheumatoid arthritis involves an immune system attack on ________ _________ of joints, eventually leading to bone erosion and joint deformities.
Synovial membranes
In MS, auto-antibodies create an immune attack on self-myelin in the CNS’s neurons (specifically the neuroglial cell: ________________).
Oligodendrocytes
In ________ ______, acetylcholine receptors at the neuromuscular junction are destroyed by immune cells after having been bonded by auto antibodies.
Myasthenia Gravis
Auto antibodies bind with self molecules to create ______ _________.
Immune complexes
__________ ________ refer to excessive or inappropriate activation of the immune system to exogenous and endogenous antigens that produce inflammation and cause tissue damage.
Hypersensitivity disorders
Type of hypersensitivity response mediated by IgE which leads to the release of inflammatory mediators from sensitized mast cells. The reaction takes place with the second and subsequent exposures to the antigen, not with the initial exposure.
Immediate Hypersensitivity
Immediate Hypersensitivity begins rapidly, often within minutes of an antigen challenge. Often referred to as _______ __________, the antigen in this case would be referred to as an allergen.
Allergic Reactions
Type I responses vary in severity:
• Mild, but annoying (ex. _______ _______)
• Severely debilitating (ex. ________)
• Life threatening (ex. ___________)
- Mild, but annoying (ex. seasonal allergies)
- Severely debilitating (ex. asthma)
- Life threatening (ex. anaphylaxis)
Type I response characterized by edema and hypersecretion of mucosal lining of the nasopharyngeal cavities by allergens like pollen.
Allergic Rhinitis
Lung disorder characterized by bronchoconstriction, edema, and increased secretion of thick mucus in the bronchi à constriction of airways.
Asthma
Type I response characterized by local wheals and erythema in the upper dermis.
Urticaria (hives)
Generalized edema of skin, lips, face, tongue, pharynx, and/or mucosa.
Angioedema (aka Quincke’s edema, Angioneurotic edema)
A systemic life-threatening hypersensitivity reaction. An acute generalized reaction characterized by itching, generalized flushing, headache, difficulty breathing, and a drop in blood pressure which can lead to shock and loss of consciousness.
Anaphylaxis
Type of hypersensitivity response mediated by IgM or IgG, this response is directed against target antigens on cell surfaces or in extracellular tissue. These reactions commonly involve the formation of antibodies directed against blood cells and their destruction.
Type II - Antibody Mediated Hypersensitivity (aka Cytotoxic Hypersensitivity
This is a hemolytic disease that affects neonates hemolytic anemia/erythroblastosis neonatorum in neonates
Erythroblastosis Fetalis
Type II response where antibodies produced by a patient’s own body are responsible for the hemolysis of erythrocytes.
Autoimmune Hemolytic Anemia
This type II response is triggered when an incompatible blood type is administered.
Blood Transfusion Reactions
Type II response where the body produces antibodies that are directed against platelets.
Autoimmune Thrombocytopenia (AITP)
Type of hypersensitivity response mediated by formation of antigen-immunoglobulin complexes, complement fixation, and localized inflammation; this response involves IgM and IgG antibodies.
Type III - Immune Complex Mediated Hypersensitivity
Type III response; performed for experimental purposes and involves the injection of a foreign substance. This usually results in complex formation and localized skin reactions (edema, hemorrhage, necrosis).
Arthus Reaction
Type III response caused by animal serum or drugs (ex. penicillin).
Serum Sickness
Type III response where an acute streptococcal infection is responsible for the formation of antibodies.
Glomerulonephritis
This disease is characterized by the inflammation and necrosis of medium-sized arteries with secondary ischemia of the tissues supplied by the affected blood
vessels.
Polyarteritis nodosa
Type of hypersensitivity response mediated by specifically sensitized T-lymphocytes, this response manifests as sub-acute or chronic inflammation with infiltration of the tissue by the lymphocytes and macrophages, resulting in variable degrees of necrosis.
Type IV - Delayed or Cell-Mediated Hypersensitivity
An acute or chronic delayed type of hypersensitive response to allergens placed on the skin surface.
Contact Dermatitis
Development of chronic inflammation because of infiltration of the graft by lymphocytes and macrophages. This leads to necrosis of the graft.
Graft Rejection
Latex allergies can be Type _ and/or Type _ Hypersensitivity
• Type _ latex reactions are immediate and often life-threatening
• Type _ latex reactions are more common and tend to manifest as contact dermatitis
Type I and/or Type IV
• Type I latex reactions are immediate and often life-threatening
• Type IV latex reactions are more common and tend to manifest as contact dermatitis
Organisms so small they are invisible to the naked eye and can only be seen with a microscope. Can be pathogens or non-pathogens.
Microorganisms
T/F: All microbes are microorganisms, but not all microorganisms are microbes
True
The presence and multiplication within a host of another living organism with subsequent injury to the host.
Infection
The ability of an organism to enter, multiply, and survive in a host.
Infectivity
