Pathology Lesson 4 Flashcards
What is the first line of defense of the immune system?
- Innate
- Non specific
What is the second line of defense of the immune system?
- Inflammation (also non-specific)
What is the third line of defense of the immune system?
- Adaptive defense
What are the non-specific defenses?
- Skin & mucosa
- Phagocytes
- Natural killer cells
- Antimicrobial proteins
- Fever
- (Inflammation also non-specific)
Is having a fever a good thing and why?
It depends (haha) - Mild to moderate fever is beneficial - A really high temperature can denature cells
What are the physical and mechanical barriers?
- Skin, Conjunctiva, Mucous Membranes
- Lining of the GI, GU and respiratory tracts
- Mucus
What are the immune system barriers that involve ciliary action of the mucus?
- Coughing
- Sneezing
- Vomiting
What are different biochemical barriers?
- pH of Skin
- Secreted saliva / Tears / Earwax / Sweat / Sebum
- Antimicrobial peptides
- Normal bacterial flora
What is the pH of the skin?
3-5 (acidic)
What is the pH of the gastric tract?
1.5-3.5
What is the pH of the vagina?
3.5-4.5
What do high amounts of yeast usually indicate?
Glucose imbalance (diabetes)
Where does E. coli live in our body and how does it help us?
- live in the intestines
- help our body break down the food we eat as well as assist with waste processing, Vitamin K production, and food absorption.
Although E. coli can help in food absorption, what can it cause in humans?
Urinary tract infection
What are different biochemical barriers that have antimicrobial properties?
- Sweat
- Earwax
- Tears
- Sebum
What plant is a lysozome similar to? Why?
- Venus fly trap (secretes enzymes that digest the fly)
- Lysomoes engulf something and digests it
What are some types of phagocytes? What is the most common?
- Monocytes –> most common
- Macrophage
- Neutrophils
- Eosinophils
- Mast Cells
What is opsonization?
A cell is coated with IgG and Immonglobulin G. It recognizes C3B (a compliment protein) on the bacteria which tells the cell “I’m good to eat.”
What is the order of events of phagocyte mobilization?
- Neutrophils enter blood from bone marrow
- Margination (pavementing)
- Diapedesis
- Positive chemotaxis
How do Natural Killer Cells kill?
They don’t kill by engulfing. They punch holes in the cell membrane and damage the cell membrane in a similar mechanism of apoptosis.
What does MAC stand for? What is it’s function?
- Membrane Attack Complex
- Another system that is activated to defend and remove the bacteria
What is the mechanism of Interferons? What else do they have an affect on?
Think virus. Interferons can induce synthesis of antiviral proteins (in unaffected cell) that interfere with viral replication. It has an affect on inflammation as well.
What do Complement proteins do in immunity? What effect do they have on the cell?
- Insert themselves into the membrane and creates a pore
- Water enters the cell
- The cell lyses
Why does a fever happen?
Endogenous pyrogens change hypothalamic “set point”
What is FUO?
FUO = Fever of Unknown Origin
What is the Lymphatic system composed of?
- Lymph
- Lymphatic vessels
- Lymphoid tissues
- Lymphoid organs
What is lymph?
Interstitial fluid in lymphatics
What are the components of lymphatic vessels?
- Duct
- Trunk
- (Node)
- Capillary
In which system are B & T lymphocytes and phagocytic cells produced?
Lymphatic system
What are the lymphoid organs?
- Nodes
- Spleen
- Thymus
- Tonsils
Which direction does lymph flow?
Unidirectional - Valves prevent back flow of tissue
What is one of the functions of the lymphatic system?
The lymphatic system is a collection site of cellular debris.
What are the characteristics of nodes? What are some indications of abnormalities of these characteristics?
Nodes are usually soft and spongy
- If they are hard and thick it indicates the presence of cancer
- If they are tender & large indicates an infection
What do inflamed inguinal nodes indicate?
STD
What is splenomegaly?
Enlarged spleen from accumulation of infections microorganism
What is lymphadenopathy?
Any enlargentment or abnormality of the lymph nodes
What is the sentinel node?
The first node that receives lymph drainage from a suspected cancer
What is lymphedema?
Collection of lymph because of compromised lymphatic system
What are the 3 cell types? What are the cells called?
- RBC –> Erythrocytes
- WBC –> Leukocytes
- Platelets –> Thrombocytes
What are the 2 types of leukocytes?
- Granulocytes
- Agranulocytes
What distinguishing characteristic categorizes a granulocyte or agranulocytes?
The way they stain
In leukocytes, what is diapedesis?
A retraction of the junction between the cells in the endothelial fluid when phagocytes move out of capillaries (Ameoboid motion)
In leukocytes, what is chemotaxis?
When something is attracted by chemicals
What are polys?
Polymorphoneucleocytes are a type of granulocyte
What is margination?
When phagocytes line up on the cell wall of the endothelial. This occurs before the penetrate the tight junctions.
What are the characteristics of inflammation?
- Hot
- Red
- Swelling
- Pain
- Decreased function
What are the chemicals involved during inflammation?
- Histamine
- Kinins
- Prostaglandins
- Complement
- Cytokines
Why does a injury site get red and hot during inflammation?
Because of vasodialation
Increased permeability of cells during inflammation results in what physiological effect?
Swelling
What are causes of the activiation of inflammation?
- Infection
- Trauma
- Chemical agents
- Ischemias
- Nutrient deprivation
- Temperature extremes
- Ionizing Radiation
What does activation of mast cells initiate?
Imflammatory response
What causes the activation of mast cells?
- Physical injury
- Chemical toxins
- Immunological activation (Complement/Antibodies)
- Toll-Like Receptors (as activated by bacteria, viruses)
What are adaptive (specific) defenses?
Antigen specific, systemic defense system that use memory cells to recognize the presence of repeated pathological invaders.
What are the two types of adaptive defenses?
- Humoral Immunity (Antibody-mediated)
- Cell mediated immunity
What is passive immunity?
When a person is “given” antibodies - May be natural or acquired
What are the two types of immunity in an individual host?
- Passive Immunity
- Active Immunity
What is active Immunity?
Body exposed to antigen –> generates immune response
(Wiki: Acquired immunity creates immunological memory after an initial response to a specific pathogen, leading to an enhanced response to subsequent encounters with that same pathogen. This process of acquired immunity is the basis of vaccination.)
How long does active immunity last?
- may take from days to weeks to years
- may be natural or acquired
What is natural active immunity?
Patient has disease and then recovers
What is acquired active immunity?
Vaccination
What is an attenuated pathogen?
- Not the full strength
- Not going to make you sick
What is an antigen?
Molecule of molecular complex that reacts with performed components of the immune system
What is an immunogen?
Antigen that stimulates the immune system (induce component formation).
What are haptens?
Small antigens that may become immunogenic.
What are histocompatibility antigens?
- Recognition of self
- proteins found on cell membrane
- genes are located on chromosome 6, known as HLA (Human Leukocyte Antigens) Complex
How does your body recognize itself?
Histocompatibility antigens
When you have an autoimmune disease, what is there a ploblem with?
Your histocompatibility antigens
What are types of antigens that antibodies bind to?
- Toxin molecules
- Virus
- Bacterium
The antigen-antibody complex fixes and activates what? What does it enhance and what does it lead to?
- Complement system
- Enhances phagocytosis and inflammation
- Leads to cell lyse
What three things is the antigen-antibody complex inactivated by? What does it enhance?
- Precipitation (soluable antigen)
- Agglutination (cell bound antigens)
- Neutralization (masks dangerous parts of bacterial exotoxins, viruses)
- Enhances phagocytosis
Cell mediated immunity includes what two types of cells?
- Effector T cells
- Regulatory T cells
What is an example of an effector cell?
Cytotoxic T Cells (CD 8)
What is the function of preforin?
(Wiki: Perforin is a cytolytic protein found in the granules of Cytotoxic T lymphocytes (CTLs) and NK cells. Upon degranulation, perforin inserts itself into the target cell’s plasma membrane, forming a pore.)
What is an allergen?
Nonpathogenic antigen
What is Immediate hypersensitivity mediated by?
Antibody
What are the categories of hypersensitivity?
- Immediate
- Delayed
What is an example of delayed hypersensitivity?
Tuberculosis
How is Tb related to hypersensivity?
(+) ppd test means you had a delayed hypersensivity reaction to Tb.
If you test (+) for Tb, what must you check for?
(+) Results: Check for redness and insuration (local swelling)
What vaccine prevents Tb?
- BCG vaccine
- You could be (+) from a vaccine shot (BCG) that is given in certain countries
What is the most sever form of immediate hypersensivity?
Anaphylaxis
What type of hypersensitivity is anaphylaxis?
Type I (IgE mediated)
What are the symptoms of anaphylaxis?
- Dyspnea
- Visceral edema
- Hypotension (from widespread vasodilitation)
Whats is anaphylaxis treated with?
epinephrine & corticosteroids
What are some characteristics of poison ivy?
- Extremely immunogenic
- Catechol molecules (plant) + skin protein = Complex (allergen)
- Follows the line of contact
- You become hypersensitive to it the 2nd time you come into contact with it
What are the stages of infection?
- Colonization
- Invasion
- Multiplication
- Spread
Can an organism be both beneficial and pathogenic?
- Normal one that was mutualistic can become pathogenic
OR
-An organism can be beneficial in one part of the body but pathogenic in another part of the body
OR
-An organism that is beneficial but the overgrowth or excessive production makes it pathogenic
Where can opportunistic organisms be found?
All around us
What are seven factors for infections?
- Mechanism of action
- infectivity
- Pathogenicity
- Virulence
- Immunogenicity
- Toxigenicity
- Portal of entry
What are two pathogen defense mechanisms?
- Surface coats
- Antigenic variation
What are surface coats?
Inhibits phagocytosis, surface receptors to bind host cells, and toxins
What are the two components of antigenic variation?
- Mutataion (antigenic drift)
- Recombination (antigenic shift)
What is an example of bacterial virulence?
Bacteremia / Septicemia
What is bacteremia or septicemia?
Presence of bacteria in the blood due to a failure of the body’s defense mechanism
What does Ebola do?
Bleed from everywhere!
What is a viral infection?
An obligate intracellular parasite
What are obligate intracellular parasites?
- Dependent on host cells
- No metabolism or incapable of independent reproduction
- Need permissive host cell
- Usually self limiting (Unfortunately some will kill you, but some won’t)
What are the clinical manifestations of infectious disease?
- Variable depending on pathogen (directly caused by pathogen or indirectly caused by products)
- Fever
What are vaccines? What are five examples of vaccines?
Induction of long-lasting protective immune redponses that will not result in a disease in a healthy recipient
- Attenuated organism
- Killed organism
- Recombinat viral protein
- Bacterial antigens
- Toxins
What do pathogenic adaptions lead to?
- Supression of immune response
- Development of resistance
What two factors cause drug resistance?
Antibiotic Overuse + Mutations
What is systemic lupus erythematosus (SLE)?
An auto-immune disease that results in a deposition of cicrulating immune complexes.
What can SLE result in?
- Arhritis
- Kidney disease
- Thrombus / embolus
What action of the mucus is a mechanical barrier of the immune system?
Ciliary action
What is the function of a phagocyte?
Engulf/ ingest foreign particle
What is the function of a lysosome?
Digestion/Destruction of foreign particle
How is a foreign particle exported from the cell during phagocytosis?
Exocytosis
In phagocytes, what is recognition enhanced by?
Complement, Ab
Is a natural killer cell a specific or nonspecific line of the immune system?
- Not bound to antigen - relatively nonspecific
What is the mechanism of action of natural killer cells?
Not phagocytic. They punch holes in membranes
What are the 4 stages of functions in complement antimicrobial proteins?
- Plasma protein is activated
- Enhances phagocytosis
- Causes inflammation
- Lyse cell membranes (just like NK Cells)
What does TNF stand for?
Tumor Necrosis Factor
What is Natural Passive immunity?
Antibodies transferred to a fetus through placenta or breast milk
What is Acquired Passive Immunity?
Serum with antibodies (Ig) from immune persons injected/infused into patient (Antibodies that are injected to one human from another human)
What are two examples of acquired active immunity?
- Teatnus
- Rabies
What four things do phagoctyes do to a foreign particle?
- Engulf it
- Lysosome digests it
- Exocytosis
- Recognition enhanced by complement –> Antibody
What are natural killer cells?
Specialized lymphocytes
What do natural killer cells kill and what kind can they lyse?
- Virally infected cells
- Cancer cells
What two pathways activate plasma proteins?
Classical or alternative
What are cytokines?
Non-antibody proteins released by immune cell upon contact with antigen.
What are the three types of granulocytes?
- Neutrophils
- Eosinophils
- Basophils
What are the two types of agranulocytes?
- Lymphocyte (T&B)
- Monocytes
What are two forms of natural passive immunity?
- Antibody crosses placenta from mother to fetus
- Also passed through breast milk
What is acquired passive immunity?
Serum with antibodies (Ig) from immyne persons injected / infused into patient.
What are two kinds of regulatory cells?
- Helper T Cells (CD 4)
- Suppressor T Cells
What is delayed hypersenesitivity mediated by?
T lymphocye
What is type I hypersensitivity mediated by?
IgE
What is type II hypersensitivity mediated by?
Antibody
What is type III hypersensitivity mediate by?
Immune-complex
What is type IV hypersensitivity mediated by?
T-Cell (delayed)
What three things might cause anaphylaxis?
- Drugs
- Insect venom
- Foods
On first contact with poison ivy, T-cells become what and how long does that take?
- T memory cells
- 7-10 days
On second contct with poison ivy, T memory cells become what? How long does this take? What do these activate?
- Many active cells
- 1-2 days
- Dermatitis
What are eight classes of infectious microorganisms?
- Virus
- Chlamydia
- Rickettsia
- Mycoplasms
- Bacteria
- Fungi
- Protozoa
- Helminths
Bacteremia or septicemia is usually caused by what kind of bacteria?
Gram-negative
In bacteremia or septicemia, toxins relased in the blood cause the release of what? What do they do?
- vasoactive peptides and cytokines
- produce widespread vasoldilation
What does fever reset? What is it caused by?
- Resetting hypothalamus
- Endogenous pyrogens
How does stress help cause disease?
A person experiences stress when demands exceed coping abilities, resulting in disturbances of cognition, emotion, and behavior that can affect well-being.
What are three stages of general adaptation syndrome?
- Alarm stage (arousal of body defenses - fight or flight)
- Stage of resistance or adaptation
- Stage of exhaustion
Stress and disease may be related to what chronic inflammatory processes?
- Cardiovascular disease
- Type II Diabetes
- Some cancers
- Rheumatoid arthritis
SLE has a large variety of autoantibodies. What are they?
- Antinuclear antibody
- Anti-doublestranded DNA
- Anti-Smith antibody
