Immunity, Inflammation, and Infection Flashcards
Study Guide 4
What makes up the first line of human defense?
physical, mechanical, and biochemical barriers
What are some physical barriers?
endothelial linings, saliva and tears, mucus, urine
What are some mechanical barriers?
coughing, swallowing, vomiting, diarrhea, cells dying off and carrying bacteria with them
What are some biochemical barries?
saliva, sweat, tears, earwax (all have defensins that disrupt bacteria)
What is our normal microbiome?
the microbiota existing in or on our body that play a role in immune defense
How does our normal microbiome help immunity?
it protects against pathogens, aids in digestion and absorption, and release antimicrobial secretions
Is inflammation a specific response, why?
inflammation is a NON-specific response, we see it used throughout immunity regardless of the trigger and it acts the same way
What are the 4 systemic effects of inflammation?
1) redness
2) pain
3) heat
4) swelling
What is the vascular portion of inflammatory response?
vessels will vasoconstrict to increase blood and vascular permeability in that area
What are the predominant cells in inflammation response?
neutrophils, macrophages, dendritic cells, mast cells, basophils and eosinophils
What are the three plasma protein systems?
complement system, clotting system, and the kinin system
What does the complement system do?
the complement system signals for more cells to join it, causing a complement cascade; this ultimately leads to activation of the membrane attack complex
What does the membrane attack complex do?
it initiates a response that punches holes in the membrane of pathogens so cell lysis occurs
What does the clotting system do?
the clotting system lays fibrin mesh down to stop bleeding; catching pathogens for phagocytes to show up and destroy them; provide base for wound to heal from
What does the kinin system do? How is it triggered?
the kinin system is triggered by the clotting system; it ends in vasodilation and increased vascular permeability/pain
What is opsonization? How does it relate to the complement cascade?
opsonization is a system of coating/tagging pathogens for destruction; complement sees opsonized pathogens and knows to attack/destroy them
How does the chemotactic factor affect the inflammatory process?
the chemotactic factors works to “taxi” over more immune cells; increasing inflammation in order to destroy pathogens
What are common cellular mediators of inflammations?
cellular receptors, cellular products, mast cells and basophils, endothelium, platelets, and phagocytes
What do mast cells and basophils release to trigger inflammation?
histamine!
Which step in phagocytosis involves the movement of white blood cells to site of infection?
margination and diapedesis
What immune cells are the first responders to infection?
neutrophils
What are the steps of phagocytosis?
1) tissue damage, adherence, margination, diapedesis
2) recognition and attachment
3) phagocytosis
What happens in phagocytosis?
phagocytes recognize pathogens, consume/engulf them, and then destroy them with enzymes
What is primary intention wound healing?
the edges of a wound are pulled together for growth and heal top down; minimal tissue damage
What is secondary intention wound healing?
lots of collagen is laid down due to large wound or reopening of wound and heals bottom up; lots of scar tissue forms
What is the clinical process of infection?
1) incubation
2) prodromal stage
3) invasive stage
4) convalescence
What is the incubation stage of infection?
the stage the individual is an asymptomatic carrier for the bacteria
What is the prodromal stage of infection?
the stage where the host begins to not feel well
What is the invasive stage of infection?
full blown sickness, inflammation, fever, etc.
What is the convalescence stage of infection?
the illness has successfully been destroyed, host starts to feel better
What microorganisms do natural killer (NK) cells attack?
they kill host cells that are infected by pathogens and tumor cells; they signal these host cells to kill themselves (apoptosis)
What are the classes of microorganisms?
infectious bacteria, infectious fungi, infectious parasites, and infectious viruses
What are infectious bacteria?
prokaryotic cells that cause disease through the release of toxins, invasion, or bacterial products
What is the difference in gram-negative/positive bacteria?
gram-negative bacteria contain a thin-membrane; gram-positive bacteria contain a thick membrane
When do bacteria release toxins?
typically when they are stressed, they release toxins as a “middle-finger” to the host that can damage and disrupt function
What are endotoxins?
poisonous secretions from a bacteria that cause disease; can contribute to multi-system failure
What kind of bacteria release endotoxins? When are they released?
gram-negative bacteria release endotoxins from their cell walls when the cells are lysed
What are exotoxins?
poisonous secretions from a bacteria that cause disease; can cause lots of bad issues like sepsis; very dangerous
What kind of bacteria release exotoxins? When are they released?
gram-positive bacteria release exotoxins when they grow
What are infectious fungi?
organisms from plants or animals seen as mold or yeast in the environment (uncommon)
Who is most susceptible to fungal infections?
cancer and tuberculosis patients
What are infectious parasites?
organisms that live in or on a host and cause harm to them for their own benefit
What is an issue to be aware of with parasites?
parasites are typically easy to treat, but it takes time for us to identify their presence
What are infectious viruses?
pathogens that cause illness but infecting/hijacking cells in the host to replicate themselves via the host’s replication methods
What protects a virus’s nucleic acid?
their nucleic acid is protected by a protein shell called a capsid
How do we classify viruses?
we classify them by their nucleic acid; we have 7 classifications
What helps viruses attach to our body cells?
spikes on their outer surface
What is HIV?
a specific virus that attacks the body’s immune system and can lead to AIDS
How does HIV spread?
HIV spreads through sexual contact or contact with blood (or bodily fluids)/needles
What is the pathogenesis (development) of HIV?
stage 0) the patient is an asymptomatic carrier, this stage lasts 180 days
stage 1,2,3) all based off of CD4 counts, the higher the CD4 the longer you’ve had it
What are some clinical manifestations of HIV?
fever, headaches, and fatigue (very vague symptoms)
