rrd 3 Flashcards
mechs of defense: inflammation, immune fxn and disorders
general description of body’s defenses
an interaction and coordination of responses to stressors
example of stressors
- invasion by a foreign body, such as microbe, splinter, etc.
- development of unnatural dangers, such as cancer cells
the immune system
the body’s defense systems in total (innate resistance and acquired immunity)
innate (natural) resistance
the defense mechanisms we are born with (1st and 2nd line of resistance)
1st line of resistance (first defense against invasion)
- body’s physical/mechanical and biochemical barriers (and what can breach them)
- immediate
- non-specific
what does it mean for the 1st line of resistance to be immediate?
response occurs at the time of contact with a stressor
what does it mean for the 1st line of resistance to be non-specific?
the response process is the same, regardless of the type of stressor
2nd line of resistance (secondary defense against invasion)
- inflammation
- immediate
- non-specific
innate category can also include states of _______ that are related to our species: human beings are ______ _______ to some infectious agents that cause illness in other species and vice versa.
resistance, naturally resistant
examples of resistance to infectious agents depending on species
- canine distemper cannot be caught by humans
- West Nile virus can infect birds, humans, horses, but not dogs or cats
acquired (adaptive) immunity is what line of defense?
3rd line of defense
acquired immunity
- being able to resist certain diseases or conditions due to immunocyte involvement
- delayed
- specific
immunocytes are what kind of cells?
lymphocytes - B cells and T cells
what does it mean for acquired immunity to be delayed?
response occurs later than the time of contact with a stressor
what does it mean for acquired immunity to be specific?
different immunocytes respond to different types of stressors
the first line of defense includes what organs?
- skin and its glands
- membranes/glands of body openings
if a stressor breaches/breaks down the first line of defense, what happens?
2nd and 3rd lines of defense are next in line to defend us
examples of defensive roles of skin and its glands
- protects more vulnerable areas underneath from simple environmental hazards
- desquamation of skin
- various glands in skin secrete sweat (antibacterial and antifungal properties)
what is desquamation of skin?
shedding of skin cells = bacteria shed too
sweat secretion from glands in skin
- attack cell walls of certain bacteria
- contribute to making the skin acidic (pH 3 to 5); inhospitable to most bacteria
stressors that can breach the 2st line of defense
- lacerations
- abrasions
- punctures
list of membranes/glands of body openings
- eyes’ defense
- respiratory system defenses
- gastrointestinal system defenses
- genitourinary system defenses
eyes’ defense
- tears
- eyelashes
tears: ______ causes lacrimal glands to spread _____ over eyes and the _____ drains into lacrimal ducts, ______ the eye regularly.
blinking, tears, tears, washing
stressors that can breach eyes’ defense
- dry eye syndrome
- Sjogren’s syndrome
dry eye syndrome
manufacturing of tears slows down; happens to some degree to almost everyone as they age
Sjogren’s syndrome
autoimmune disease that dries up all lubricating fluids in the body
in resp system defenses, the ______ of mucus in ____ plus _____ traps bacteria (same with wax and hair in ears)
viscosity, nose, hair
in resp system defenses, ____ of cells in _____ can sweep away foreign bodies.
cilia, bronchi
cough reflex
if a foreign body is inhaled and reaches the carina, cough reflex stimulated
stressors that can breach the resp system defenses
- cigarette smoking changes bronchial cells - no more cilia (metaplasia)
- cough reflex suppression such as in head injury or stroke
gastrointestinal (GI) system defenses
- saliva
- stomach
- gag reflex/vomiting
- bowels
saliva contains?
protective enzymes
in the stomach. ____ destroys most microbes
HCl
gag reflex/vomiting
gets rid of injurious agents such as harmful bacteria
in the normal bowel are many ____ _____ - microbes that do not harm us but do keep out malicious microbes by competing for food
good flora
defecation
- part of bowel defense
- gets rid of injurious agents such as harmful bacteria
stressors that can breach gastrointestinal system defenses
- Sjogren’s
- anything that changes the bowel flora can leave us open to invading microbes
Sjogren’s with GI system
dries up saliva - less protection in mouth
example of something that might change bowel flora
antibiotics can wipe out bowel flora
genitourinary (GU) system defenses
- flow of urine washes away microbes
- vaginal secretions slightly acidic to kill bacteria
stressors that can breach GU system defenses
- decreased urine flow, as in kidney stones or kidney failure
- anything that changes vaginal acidity, such as douching
the second line of defense is?
a normal inflammatory process
inflammation is a state of _____ defense characterized by?
- innate
- being immediate and non-specific
- expected manifestations such as a certain normal degree of SHEP (swelling, heat, erythema, pain)
SHEP is manifestations of (S&S of)?
- swelling, heat, erythema (redness), pain
- local inflammation
inflammation is a ______, important body mechanism that helps us defend against stressors, begin the _____ process, and calling the ____ line of defense as needed.
normal, healing, 3rd
inflammation is an _______ processes, but it is not _____.
uncomfortable, abnormal
what happens when the first line of defense, the skin, is breached (ie. a cut or laceration from a knife)?
- area becomes red and sore as normal inflammation takes place
- immediately, certain processes take place during inflammation (clot formation to stop bleeding)
- fibrin components are weaved together to form a scab to seal the breach
- less painful as it heals
what happens when a cut becomes infected?
inflammation increases and becomes more painful, but eventually it heals
what happens when you get an upper resp infection?
fever and aches (miserable, but get well)
a normal inflammatory process is usually?
- acute
- short-lived
a inflammatory process is only considered a disorder when?
- gets out of control
AND/OR - occurs inappropriately
AND/OR - becomes chronic (lasts longer than 2 wks)
examples of chronic inflammation
- bacteria w/ cell walls that are resistant to breakdown by the phagocytes
- irritants (chemicals, a retained splinter, or dust particles) that cause a prolonged inflammatory response
purpose of inflammatory response
to facilitate shifting of substances from blood into injured/irritated tissue
facilitating shifting of substances from blood to injured/irritated tissue allows?
- clean up of the area, begin clotting process, and promote healing
- stimulate and enhance immunocyte response (3rd line of defense) as needed
inflammatory mediators
subset of biochemical mediators that act on the body
components of the inflammatory response
- irritation/injury of tissue triggers leakiness in 3 ways (same response anywhere in the body)
- the neutrophils + macrophages phagocytize any dirt, debris, dying tissue, and/or microbes they might find in the tissue area
- if bacteria, viruses, or other microbes are part of the mix above, macrophages will have phagocytized and processed them and now need help from the 3rd line of defense (lymphocytes) to help kill microbes and create memory of the microbe
- clotting factors, platelets, and fibrin come together in various ways in the area to create healing, granulating tissue
how is leakiness stimulated?
- irritated/injured cells that make up the tissue undergo disruption of metabolic pathway
- cell membrane loss of integrity and leakage of fluid + other substances from all injured cells in the area
- mast cell degranulation occurs
- HLP causes capillaries in area to swell up and “relax”, making capillary more permeable, then leaks plasma from the blood vessel into the tissue
what is mast cell degranulation?
- mast cells are specialized WBCs throughout any tissue area
- when stimulated by an irritant or injury, they degranulate - leak chemical granules
what are the chemical granules mast cells leak?
local inflammatory mediators - histamine, leukotrienes, prostaglandins (HLP)
the HLP cause capillaries to swell up and “relax.” what is this called?
vasodilation
the leaked plasma from the blood vessel that is going into tissue contains?
neutrophils, clotting factors, and fibrin
if ___ inflammation is needed, the _____ inflammatory mediators come to the area via the bloodstream to pour fuel on the fire.
more, systemic
what are the systemic inflammatory mediators called?
acute phase reactants
examples of acute phase reactants
- CRP (C-reactive protein)
- complement
- circulating prostaglandins
- kinins
- cytokines
- clotting elements like factors
the capillary swelling and cellular leaking that is part of the inflammatory process partly causes what?
S&S of swelling, heat, erythema, and pain
- swelling causes irritation to nerve endings in the area, leading to pain
always think of _____ and ______ of capillaries and other blood vessels when thinking of inflammation. why?
- vasodilation and leakiness
- no matter where and under what circumstances inflammation is occurring, there is going to be some degree of vasodilation and increased capillariy permeability in the area
neutrophils
- phagocytic WBCs from the blood
- circulating
- kills microorganisms in blood and tissue
macrophages
- phagocytic cells in the tissue
- start life as circulating monocytes and end up in the tissue as their home
- permanent WBC of the tissue
neutrophils
- circulating phagocytes
- kill microorganisms in blood and tissue
lymphocytes
- immunocytes
- T-lymphocytes and B-lymphocytes
exudate
a thick fluid that is a combination of plasma, phagocytes, dead tissue cells, bacteria, fibrin
when there is little microbe involvement, the exudate is a ______ and is called?
- clear gold color (color of plasma leaking out in the area)
- serous exudate
when there is little microbe involvement and there is also some blood, the exudate is called?
serosanguinous
if there is more microbe and WBC involvement (infection), the exudate becomes?
- thick, whitish or yellowish
- purulent exudate or pus
the memory of the microbe developed by the 3rd line of defense is also called?
immunity
to involve the lymphocytes, the macrophages will?
- secrete chemotactic substances to call immunocytes (usually T cell or CD4 lymphocytes) to come to the area via bloodstream
- display remnants of the microbes on the cell membranes as a guide to the T-lymphocytes (“this is the enemy… create more defenses”)
degranulation
breaking apart of mast cells with spillage of granules of biochemical mediators into tissue
granuloma
a hunk of tissue that has been chronically inflamed and is now essentially just scar tissue
granulating tissue
pink, healthy, healing tissue
local internal examples of inflammatory response
- appendix gets irritated by piece of food or microbe -> normal inflammation responds to the irritation -> appendicitis
- pleuritis
- thyroiditis
inflammatory response can be ____ or ____.
local or systemic
local external example of inflammatory response
- laceration
- abrasion to skin
appendicitis becomes a ____ process because it is ultimately _____ to the body, but the initial _____ was a normal defense of the body
disease, harmful, inflammation
thyroiditis
thyroid is inflamed bc of autoimmune attack
pleuritis
inflammation of pleura when irritated by something like lung cancer cell
systemic inflammatory response happens when _____ needs the extra help of the systemic _____ like more ____ and more ___ ____ ____.
body, cavalry, leukocytes (leukocytosis), acute phase reactants (often causing fever)
normal systemic inflammatory response
basically the same as a local one, but w/o a specific focus
any stressor which activates and involves a local inflammatory response can the cause the activation of?
a systemic inflammatory response
example of normal inflammatory response associated with big toe
- localized injury with infection of big toe
- local inflammation is initiated
- local inflammatory mediators activate a systemic inflammatory response
example of normal inflammatory response associated with bladder
- localized infection of the bladder
- local inflammation begins
- microbe(s) toxins enter blood stream (bacteremia)
- activates systemic inflammatory response (HLP + acute phase reactant, large #s of WBC)
example of normal systemic inflammatory response when a traumatic injury occurs (ie car accident)
- local inflammation initiated
- local inflammatory mediators activate a systemic inflammatory response
S&S of systemic inflammation
- malaise, aches, pains
- fever
- CBC shows increased WBCs (leukocytosis)
- elevated seurm CRP
where does fever due to systemic inflammation come from?
from response to increased PGs and acute phase reactants
purpose of fever
beneficial effect of directly killing some microorganisms
deleterious effects of fever
- fever dilate blood vessels -> too much vasodilation -> low BP
- fever increases metabolic rate -> may cause decompensation in ill/debilitated/elderly patients
heat ___ vessels, cold ____ vessels.
dilates, constricts
leukocytes (WBCs) ____ in number as they are summoned to the areas of ____
increased, inflammation
the WBC subtype that is usually most increased during inflammation is?
neutrophils (neutrophilia)
example of a lab report showing leukocytosis and neutrophilia
- total WBCs count: 15000 K/ul (norm is 5-10000)
- percentage of neutrophils: 80% (norm 50-75%)
why is the serum CRP elevated during systemic inflammation?
it is an acute phase reactant “fuel on fire”
as inflammatory mediators ______, they will exert more chemotactic influence on WBCs
increase
not enough inflammation due to?
- quantitative/qualitative defects in phagocytic fxns
- complement deficiencies
quantitative defect in phagocytic functions
- can be from chemotherapy
- leukopenia (deficiency in WBCs)
- specific deficiency in neutrophils (neutropenia)
qualitative defects in phagocytic functions
- chemotactic defects: won’t respond appropriately when summoned
- impaired function (ex: phagocytes damaged by DM have decreased ability to fight microbes)
complement deficiencies
- grp of disorders that stem from a genetic defect in synthesis of complement proteins
- patients who have defects in these have problems that are very similar to those seen in patients with antibody deficiencies
anyone with not enough inflammation will be?
extra susceptible to infections
if all goes well, inflammation is usually ____ and ______ - it gets the job done as efficiently as possible and goes away, paving the way for continued healing.
acute, short-lived
abnormal inflammation
inflammation goes into overdrive and/or becomes chronic
examples of abnormal inflammation
- SIRS
- sepsis
- septic shock
- chronic inflammation
shock
low BP that causes s&s; usually lower than 80 or 90 systolic
SIRS
systemic inflammatory response syndrome
SIRS occurs when?
- when a normal systemic inflammatory response goes into overdrive
- normal braking system does not occur
- wide spread systemic inflammation occurs in the entire body, not just in original injured or inflamed area
the excessive systemic inflammation from SIRS contributes to?
widespread impaired tissue function and organ damage
example of SIRS
- localized injury with big toe infection
- local inflammation initiated
- local inflammatory mediators activate a systemic response
- instead of healing, systemic inflammation goes into overdrive
- SIRS
- widespread tissue/organ damage
SIRS S&S (2 or more needed)
- unexplained change in mental status (confusion, not as awake and alert as normal)
- fever of more than 100.4 F
- increased HR
- increased resp rate
- abnormal WBC count
normal temperature
98.6 F
sepsis
occurs when there is a known or suspected infection and the person has SIRS
example of sepsis
- localized injury with big toe infection
- local inflammation is initiated
- local inflammatory mediators activate
- inflammation overdrive
- S&S of SIRS
- sepsis
early recognition of S&S of SIRS and identification of sepsis is key so appropriate treatment can be started early. mortality increases by ____ every hour that treatment is delayed.
10%
septic shock
occurs when sepsis (infection + SIRS) is complicated by low BP
in septic shock, ____ levels of systemic inflammatory mediators trigger widespread, extreme ____. ____ arterial vessel tone as arteries become ____ _____, _____.
high, vasodilation, no, too relaxed, floppy
when vasodilation occurs during septic shock, blood pools where instead of being part of circulation?
in the periphery
blood pooling in the periphery during septic shock causes what to the blood volume? what happens after?
low blood volume -> reduces amt of O2 being brought to tissues _ decreasing BP
S&S of septic shock
- SIRS S&S: change in mental status, fever, increased HR, increased resp rate, abnormal WBCs
- low BP
- ischemia to organs -> renal failure, resp failure, heart failure, or death
differences between SIRS, sepsis, septic shock
- SIRS: overdrive of widespread systemic inflammation w/ related S&S
- Sepsis: SIRS + infection
- Septic Shock: sepsis + low BP
normal arteries have a certain ______ _____. the muscles in their walls constrict and dilate as body needs.
vasomotor tone
chronic inflammation
last weeks or longer, regardless of cause
inflammation can be prolonged to become _____, due to persistent what?
- chronic
- bacterial contamination, foreign objects, autoimmune processes
