Immunology II Flashcards
What are the 4 major agents of human disease?
Bacteria
Virus
Fungi
Parasites
The loosely organized DNA in Prokaryotes is called…
Nucleoid
T/F
Both Eukaryotes and Prokaryotes have mitochondria, lysosomes, and other organelles.
False
Only Eukaryotes have organelles
What is the rigid cell wall of prokaryotes made of?
Peptidoglycans
*polymer of AA’s and sugars
What encompasses the Eukaryotic cell?
Flexible cell membrane or Chitin (fungi, rigid)
What is common in Eukaryotic membranes and lacking (with one exception) in Prokaryotic membranes?
What is the exception?
Sterols
Wall-less Mycoplasma
Motility of the following: Protozoa Bacteria Fungi Viruses
Protozoa - mostly motile (flagella, cilia, pseudopodia
Bacteria - some motile (flagella only)
Fungi/Viruses - non motile
What are the 3 general shapes of bacteria?
Cocci - balls
Bacilli - pills
Spirochetes - spirals
*shape determined by rigid cell wall
(peptidoglycan)
Name for cocci:
Pairs
Chains
Clusters
Diplococci
Streptococci
Staphylococci
What is the smallest bacteria?
What is the largest virus?
(they are about the same size)
Mycoplasma
Poxvirus
What are the largest Bacteria rods?
What fungus are they similar to in size?
Bacillus
Candida
*also same size as RBC’s
What is the range of size for bacteria?
0.2 - 5 micrometers
Gram positive stains ______.
Gram negative stains ______.
Purple
Pink
What two characteristics will Gram staining reveal?
+/- gram
shape
What are the 4 steps to the Gram stain?
after heating
- Crystal Violet Stain - 60 seconds
- Water, Iodine - 60 seconds
- Water, 95% EtOH or Acetone
- Safranin counterstain (red) - 60 seconds, then water
What step removes Cresyl Blue from a Gram Negative bacteria?
Why?
95% EtoH or Acetone
This extracts dye from a lipid rich, thin wall
What in the cell wall makes bacteria Gram Positive?
Gram negative?
Positive: Thick wall, Lipid poor
Negative: Thin wall, Lipid rich
What type of cell wall is Mycoplasma covered with?
None. It is bound by a cell membrane.
*only bacteria that has just a cell membrane
What is a normal bacteria bounded by?
Cytoplasmic membrane
Cell Wall
*cell wall multilayered structure
What is a bacterial cell wall composed of?
Inner - Peptidoglycan
Outer - Capsule
What is the Peptidoglycan layer of a bacterial cell wall composed of?
Repeating disaccharides, each with a 4 AA chain
*AA’s covalently bind to other chains, creating cross linkages
How does the peptidoglycan layer differ in Gram -/+ bacteria?
Positive - thick peptidoglycan multi-layer
Negative - thin peptidoglycan single layer
What surface antigen, made up of polysaccharide fibers, is seen only in Gram+ ?
*useful in serologic identification
Teichoic Acid
What 3 layers are present in the Cell Walls of both Gram+ and Gram- bacteria?
- Inner cytoplasmic mem. (lipid bilayer)
- Peptidoglycan
- Capsule
Describe the Cell Wall of a Gram negative bacteria.
Lipid bilayer
Periplasmic Space
Thin peptidoglycan layer (no Teichoic Acid)
LPS (Lipopolysaccharide)
What is the Periplasmic space filled with?
What type of bacteria is it found in?
Beta-lactamases (degrade beta-lactam drugs)
Gram Negative
What surface element is seen only in Gram+?
What is seen only in Gram-?
Teichoic Acid (+) Lipopolysaccharide (-)
What 3 components make up the LPS seen in Gram-?
1-50 oligosaccharide outer carbohydrate
center polysaccharide
Lipid A
Why is the Lipid A component of the LPS in Gram- bacteria of interest?
Lipid A is an Endotoxin
*responsible for Fever and Shock upon cell lysing
What bacteria can’t be Gram stained?
Mycobacteria
*TB, Leprosy, MAI
What doesn’t Mycobacteria stain well?
Acid-Fast
(Mycolic Acids in lipid cell wall)
After being stained with Carbolfuchsin, they resist decolorization with acid alcohol
Why doesn’t TB stain well with Gram techniques?
It is “acid fast”
What is the capsule made of?
What is its function?
note: this is the same in Gram+/-
Simple sugar residues
Makes more virulent
macrophage and neutrophils unable to phagocytize sugars
Why are the sugars in the capsule useful?
Used as antigens in vaccines
What 2 tests enable visualization of Capsules?
India Ink (doesn’t stain - transparent halo)
Quelling rxn
Methylene Blue, capsule swells, Pneumococcus
What bacteria is identified with India Ink stain?
Cryptococcus
What bacteria is identified with the Quelling rxn?
Pneumococcus
T/F
Both Gram+ and Gram- bacteria can have flagella.
True
What is the process of attractants of bacteria with flagella?
Chemotaxis
Why are P. mirabilis and E. coli common causes of UTI’s?
They have flagella
Do spirochetes move?
Yes.
Axial Filament undulates
What bacterial structure acts as an adherent?
Pili
Fimbriae
What type of bacteria are Pili/Fimbriae mostly found on?
Gram negative
What is an example of a bacteria that uses Pili for adhereence?
Gonorrhea
also E.cole, Campylobacter jejuni, Bordetella pertussis
What does Strept mutans secrete?
Glycocalyx on teeth
slime layer
What DNA containing structure forms when nutrients are depleted?
Endospore
What is responsible for endospore resistance?
Dipicolinic Acid
Calcium chelator found only in spores
What is a neurotoxin?
Exotoxin that acts on nerves
What are enterotoxins?
Exotoxin that acts in GI tract
What are 2 diseases caused by enterotoxins?
Diarrhea
Food poisoning
What makes up an Endotoxin?
Lipid A of the LPS
*Seen only in Gram negative
How is Endotoxin different from Exotoxin?
Endotoxin isn’t secreted, it’s part of the outer membrane
T/F
Internal organs have local flora
False
organs usually sterile
What is normal flora on the skin that might be problematic if it reaches the circulation?
Staph epidermidis
*wreaks havoc on artificial heart valves
Where does Staph aureus normally live?
Nose
What species of bacteria in the throat inhibit the following:
Strept pyogenes
Neisseria menigitidis
Staph aureus
Viridans Strept
Neisseria species
Staph epidermidis
What organisms can potentially invade circulation and attach to damaged heart valves?
Viridans strept
What oral flora is associated with human bites and clenched fist injuries?
Eikenella corrodens
What can anaerobic bacteria found in gingival crevices cause if aspirated?
(e.g. Bacteroides, Fusobacterium, Clostridium)
Lung abcesses
What percentage of feces is bacteria?
20%
What is the leading cause of UTI’s?
E.coli
What bacteria is associated with intestinal perforation?
B. fragilis
What is an important cause of UTI’s and endocarditis?
Strept faecalis
What is the normal flora of the vagina?
Lactobacillus species
What vaginal bacteria can be dangerous to newborns?
Group B Streptococci
What acid fast bacteria is found in women and uncircumcised males?
Mycobacterium smegmatis
What can urine become contaminated with?
Staph epidermidis and Coliforms
What are the 5 Cardinal signs of Inflammation?
Heat Redness Swelling Pain Loss of function
Calor Rubor Tumor Dolor Functio laesa
What regulates the inflow of blood to capillaries upon trauma?
Smooth muscle on pre-capillary arterioles
Why does dilation of capillaries cause swelling?
Because they’re one simple squamous cell thick and leak
*causing edema
What is the response to injury in the capillaries in the first few seconds?
vasoconstriction
vasodilation
What causes hyperemia (warmness) in inflamed tissue?
Large quantities of blood pumped in after arteriole smooth muscle relaxes
Why is blood flow congested in traumatized areas?
Release of plasma into surrounding tissue concentrates cells in vasculature
What do RBC’s form in congested vasculature?
What do WBC’s do?
Stacks “Rouleaux”
Margination and Pavementing
Describe pavementing
WBC’s stick to vasculature walls via activated adhesion molecules
What activates the adhesion molecules on Leukocytes in response to inflammation?
Interleukins
Where is the greatest concentration of Interleukins and what are they derived from?
Inflammation site
Platelets and Leukocytes
What anchors leukocytes to vessel walls during inflammation?
What initiates this process?
Fibrin strands
Platelets
The process of increased vessel permeability that creates edema is called?
Transudation
*Edema is rich in protein but few cells
Pus is an example of an…
Exudate
PMN =
neutrophils
What makes up pus?
Mostly a neutrophil exudate
What is the lifespan of neutrophils in response to inflammation?
What comes after?
2-4 days
Macrophage, Lymphocytes, Plasma cells
How do leukocytes migrate through endothelial cells?
Pseudopods
What type of substance stimulates PMN’s to an inflamed site through a concentration gradient?
Chemotactic substances
What two things facilitate opsonization in phagocytosis?
What specific receptors do they use?
Immunoglobulins (Fc)
Complement (C3)
Why do many PMN’s die in their battle with bacteria?
They discharge their specific granules kamikaze like
and make pus
What are inflammations called if they’re dominated by pus formation?
Purulent
or suppurative
What cells are dominant in Chronic Inflammations?
Lymphocytes
Macrophages
Plasma Cells
T/F
All infections have an acute phase
False
TB has slow onset and is long lasting
Silica dust exposure
Rheumatoid arthritis
Aside from infectious pathogens, what can cause inflammation?
Chemical, physical, or immune factors
What is a fever in celsius?
above 37
What are 2 examples of an endogenous pyrogen (a fever producing cytokine)?
Where do they act?
IL-1 (Interleukin) and TNF
on thermoregulatory centers in Hypothalamus
*Hypothalamus serves as a thermostat
Define pyrogen:
fever inducing Cytokine released by PMN’s and macrophages during inflammation
What mediates pyrogen action in the hypothalamus?
Prostaglandins
What is the normal range of Leukocytes in the blood?
What is the range of leukocytosis?
10,000 /mm3
12-15,000 WBC’s/mm3
What is the mildest form of inflammation?
Serous
Fibrinous inflammation occurs through ______ vessels than serous inflammation.
Larger
What are 3 examples of bacterial infections that cause fibrinous inflammation?
Strept throat
Pneumonia
TB pericarditis Bread and Butter
T/F
Fibrinous inflammation never resolves.
False
blood vessels grow into exudate
What type of inflammation forms pus?
Purulent
What is the term for a localizes collection of pus?
Abscess
Why don’t abscesses heal spontaneously?
What happens when they rupture?
Purulent matl surrounded by capsule of Fibrotic Granulation Tissue
create sinus
An abscess that creates a channel between two pre-existing cavities is knows as a…
What is the accumulation of pus in this area?
Fistula
Empyema
What type of inflammation creates a hole in epithelium?
Ulcers
*peptic best example
What type of inflammation does C. difficile create?
What are the components of this inflammation?
Pseudomembranous inflammation
fibrin, pus, cellular debris, and mucous
What is often seen in chronic inflammation?
What causes this?
Scarring
lymphs, macrophage, and plasma cells stimulate fibroblasts
What is a Granulomatous Inflammation?
Best example?
No acute phase, caused by Type IV cell-mediated hypersensitivity (or by persistent antigens)
TB
(also certain fungal diseases)
What are epitheloid cells?
Where are they seen?
Interconnected macrophage
(immobile)
Granulomatous inflammation
What accumulates in granulomatous inflammation?
T-lymphocytes and Macrophages
How do macrophage and epitheloid cells differ?
Epitheloid cells immobile and not phagocytic
*they produce inflammatory mediators
What forms multi-nucleated giant cells on the rim of granulomatous inflammations?
Epithelioid cells
T/F
Granulomas tend to be transitory
False
necrotic and persistent
What is an example of a granulomatous inflammation of the lung?
Pulmonary tuberculosis
What are the 3 classifications of cells vis a vis their proliferation?
Continuously dividing (aka Labile)
Quiescent
Nondividing
What type of cells divide throughout lifespan?
*aka?
Labile (continuously dividing) cells
*Stem Cells
What type of cell can divide but normally doesn’t?
Quiescent
What are some examples of Permanent (nondividing) cells?
Neurons and Myocardial
What cell, integral to wound healing, have hybrid properties of smooth muscle and fibroblasts?
Myofibroblasts
What stimulates blood vessels to come to an area under repair?
Angioblasts
What are the 2 components of Granulation tissue?
Collagen and Angiogenesis
What two healing substances to fibroblasts secrete?
Fibronectin (glue)
Collagen (III > I)
Describe the progression of First Intention wounds.
Coagulated blood forms Scab PMN's scavenge Macrophage (2-4 days later) stimulate: Myofibroblasts Angioblasts Fibroblasts
Granulation tissue (collagen and angiogenesis)
Fibronectin/III > I
Scar
Remodeling (III>I)
What 3 cells does Macrophage stimulate in wound healing?
Myofibroblasts
Angioblasts
Fibroblasts
What is the difference between First Intention wound healing and Secondary intention?
Collagen doesn’t progress from I to III
Define ischemia
poor O2 supply
T/F
Corticosteroid hormones have been implicated in inadequate collagen formation.
True
Define dehiscence:
Separation of wound margins
lack of tensile strength
Keloids are composed mostly of…
Type III collagen
What do mucous, saliva, tears, and prostatic secretions contain?
IgG and secretory IgA
Why is the vaginal pH low?
Lactobacillus
*inhibits Candida
What chemical barrier is found in tears and saliva?
Lysozyme
Name 4 antimicrobial chemical barriers.
Lysozyme (degrades peptidoglycan)
Peroxidase
Lactoferrin (takes Fe from microorganisms)
Defensins
How do Defensins operate?
Where are they found?
Insert peptides into microbial membrane
found in mucous membranes and phagocytes
What lines lymphatic vessels?
Endothelium
What does lymph transport?
WBC’s, fats, cellular debris, infectious agents
Where does metastasis occur?
through lymph
What are low molecular weight proteins whose main function is communication?
Cytokines
What are 5 types of Cytokines?
Interleukins TNF Chemokines Colony stimulating factors Interferons
What are the pivotal cells in direction of inflammation through expression of cytokines?
Macrophages
What 2 cytokines are produced by macrophage in response to inflammation?
(amplify inflammation)
IL-1 and TNF-alpha
What are some functions of IL-1 and TNF-alpha?
activate endothelium to release more cytokines
Mediate fever, catabolism of muscle, hemodynamic effects
What protein is produced by a subset of T-cells and NK cells that stimulates macrophage and cytokine production?
Interferon-gamma
What type of cytokines direct cell migration?
Chemokines
What are 2 functional classes of chemokines?
Inflammatory (IL-1, TNF, Interferon)
Homing
What is the function of Colony Stimulating Factor?
Stimulates production of White blood cells
*binds hematopoietic stem cells
What are the 3 types of Colony Stimulating Factor?
CSF-1 macrophage
CSF-2 granulocyte/macrophage
CSF-3 granulocyte
(CSF-3 = G-CSF)
What is one of the most potent activators of Macrophage, Endothelial cells, and neutrophils?
(to produce cytokines)
LPS - Lipopolysoaccharides
*Gram negative cell walls
How does LPS activate various cells?
Cells have LPS-binding protein receptors
Too much LPS can create…
Septic shock
Describe septic shock pathway.
LPS > LPS binding protein > CD14 > TNF-alpha > directly injures endothelial cell walls
