2450 wk 3 Flashcards
infection
invader overwhelms the body’s defenses; may not be clinically apparent
colonization
overgrowth of organisms in a body site: sometimes used interchangeably with infection, but not overwhelming to body
describe and name 3 opportunistic pathogens
normally found in host or environement, do not normally cause dz, exploit break in host defenses (candida, staph, pseudomonas)
6 links in chain of infx
- infx agent
- reservoir
- portal of exit
- transmission
- portal of entry
- host
define vertical transmission & name 3 types & effects
mother to baby
tranplacental, transcervical, breastfeeding
mental retardation, blindness, deafness
vertical transmission (TORCH)
Toxoplasmosis Other (HIV syphilis gonorrhea) rubella cytomegalovirus herpex simplex
3 methods of infx diagnosis
1 clinical evidence (systematic complaints, vital signs)
- labs
- urinanalysis
5 lab values that indicate infx
- wbc
- esr
- crp
- culture
- serology (used for titers, to ID antigens, and when culture is not possible)
purpose of U/A
screening for infx, renal funx, fluid balance
U/A test results that indicate UTI
visual: cloudy, amber
chemical: nitrite, leukocyte esterase
5 factors that determine virulence
- toxins
- adhesion factors
- evasive factors
- invasive factors
- mutations (change antigenic profile)
define toxins & toxoids
- poisonous substance released by invaders maybe modified to toxoid for immunization
- virulence factors removed, but retain antigen for T & B cells given as vaccine
define toxoids endotoxins and exotoxins
exo: released during bacterial cell growth
endo: within the cell wall of gram (-) bacteria, small amounts are harmful
describe systematic inflam response syndrome and give aka
cytokine storm that happens due to to many infectious agents
- potent response causing vasc. collapse and organ failure
- sepsis
- cytokines destroyed and trigger cascades (kinins and coagulation)
describe adhesion factors & 3 types and examples
pathogen’s ability to attach and maybe a site or cell
- hemagglutinins-viral glycoproteins that attach to cells in the respiratory tract (flu a/b, measles)
- slime- adheres to the host and also protects itself from host’ defenses (pseudomonas, strep on teeth, staph on plastic; urinary cath)
- pili fimbriae- hairlike/fringe projections that anchor bacteria to cells (like velcro) (gonorrhea )
define evasive factors and 4 examples
evading or avoiding host’s immune sys
- coagulase: envelopes invader (staph. aureus)
- protease: digests IgA (flu & gonorrhea)
- capsules: resist phagocytosis (strep, cryptococcus)
- leukocidin: kill by punching holes in membranes of neutrophil and macrophage (staph aureus MRSA)
define invasive factors
enzymes that allow penetration of tissues
define change antigenic profile and two types & two examples
are mutations in antigen that are antigenic drift (minor) & antigenic shift (major) HIV & FLU
what are the H and N in H1N1 flu virus
Hemagglutinins: glycoproteins that attach to cells in resp tract
Neuraminidase: surface enzyme of flu virus allows release of virus’ progeny from infected cells
characteristics of viruses
- small
- obligate must replicate inside cell (has only DNA or RNA (never both))
- protein coat (capsid)
- some enveloped
- may be latent
- may be oncogenic
6 steps of virus reprodux
- adsorption (attachment to target cell membrane)
- penetration (enzyme release to weaken CM and allow for penetration)
- uncoating (virus’ DNA or RNA takes off protective protein coat to go to nucleus)
- replication of genetic material
- assembly (assembly of genetic material to make new viruses)
- release (budding)
3 ways virus severity varies
- self-limiting
- cell death (herpes)
- immune complexes (HBV antigen-antibody complex cause damage)
how do retroviruses funx
reverse transcriptase converts RNA–>DNA (HIV)
characteristics of bacteria
- peptidoglycan wall
- gram (+) have thick walls that stain purple
- gram (-) more layers to wall that stain red
- when neither gram (-) or (+) acid fast test used (TB)
- can be aerobic or anaerobic
- has DNA and RNA
- subclass of spirochetes & myobacterium
Rickettsiae, Chlamydiae, Ehrlichiae characteristics
- obligate
- rigid cell wall
- DNA & RNA
coxiella characteristics
some vector transmission
contaminated food
inhalation while processing meat
fungi characteristics
yeasts- waxy
molds- cottony
dimorphic (characteristics of moth yeast and mold)
rigid wall
similar to host (some antifungals toxic because it attack PT cells)
-some only grow in cooler temp
give example 3 examples of fungi
- aspergillosis (aspergilloma fungal ball in lung scar or abscess)
- pneumocystis jirovecii : HIV
- histoplasmosis: dimorphic infx from bird dropping
describe infectious mononucleosis
- caused by EBV epstein barr virus
- 90% infx of population
- kissing disease (15-35 y.o.)
how does mono attack, signs & symp, diagnosis, complication
- attacks B lymph (self limiting 2-3 wks)
- sore throat, fever, lymphadenopathy, fatigue
- presence of Paul Bunnel Davidsohn
- lymphocytosis (10-20K)
- positive cold aggluntinin titer - splenomegaly
3 dz that have (+) cold agglutinin titer
mycoplasm pneumonia
mono
multiple myeloma
2 types of UTI and example
Upper: kidneys and ureters (pyelonephritis- inflamm of renal parenchymal tissue, systemic sx fever malaise)
lower: bladder urethra (cystitis: inflamm of bladder, sx difficult urination)
pathogens associated with UTI
gram (-) e coli klebsiella proteus mirabilis
gram (+) positive staph saprophyticus
4 ways agents exploit host poor health
- virulence (adhesion flagella hemolysin)
- antibiotic resistance
- biofilm formation
- colonization
4 causes of CAUTI
intraluminal
extraluminal
trauma
biofilms
What causes organism TB, describe and lab test used, how is it transmitted
mycobacterium (rod shaped) outer waxy capsule, aerobic organisms
-acid fast (sent 3 days in a row)
droplet nuclei
3 stressor types
- endogenous- individual is source (physical, emotional)
- exogenous- outside source
- eustress- positive and growth producing
3 stages of General adaptive syndrome
- alarm
- resistance (adaptation) flight or fight
- exhaustation (allostatic overload)
describe alarm stage and responses
- stimulate stress response: release catecholamines (Epi, Norepi neuropeptide Y & cortisol (glucocorticoid released from adrenal cortex, causes mobilization of substances & stress response)
- brain preps body for axn (alert focused tensed)
- blood pressure increase, blood shunted to muscles heart and brain
- GI tract less blood flow can cause sx N/V/D
- glucose is made available to give energy for muscles and brain
describe stage of resistance (adaptation)
feeback loop continues until balance in maintained or exhaustation
catecholamine and cortisol will drop when body adapting
describe exhaustation/allostatic overload stage
resources depleted and wear and tear appear
secretion of neuropeptide Y during chronic stress
-food intake increase, activity decrease, energy stored as fat
-seen in vascular dz :atherosclerosis & vasoconstriction
triad of constant stress
- enlargement of adrenal cortex increase in corticosteriods (mineral corticoid–> aldosterone and glucocorticoid–>cortisol)
- atrophy of thymus and other lymphoid structures
- decreases T cell activity, decrease immunity to infx & cancer
- increased autoimmune response - bleeding ulcers and inflamm of GI tract
- decrease blood flow mucosa
- increase acidity in stomach
- peristalsis inhibited
alarm rxn pathways
simultaneous pathways
stress–> ACTH impacts Cortex –> Cortex secretes cortisol–> liver releases glucose
stress –> nerve signal –> medulla –> secretion of Ephinephrine –> increased <3 rate, breathing, blood sugar
Hypothalamus Pituitary Adrenal (HPA) Axis
stress (stress stimulus may arrive through bloodstream (molecules) or impulse (thoughts) or circadian rhythm–> hypothalamus –> CRH (corticotropin releasing hormone) –>anterior pituitary –>ACTH (adrenocorticotropin hormone) –> Adrenal cortex –> cortisol –> (-) feedback on hypothalamus & anterior pituitary & increased blood glucose, amino acids, fatty acids
cortisol rxns
- gluconeogenesis
- catabolism of proteins in muscle, skin, bone, fat tissue
- redistribution of fat (lypolysis in extremities & lipogenesis in face & trunk)
- immunosuppression
- Central CRH causes overall weakened immunoresponse to conserve energy
- Peripheral CRH cause mast cell degranulation (i.e. histamine release)
- may have more allergic rxns or autoimmune disorders
describe ADH & pathway
Antidiuretic Hormone
- secreted when blood volume decreases and in response to hypothalamic stimulus (i.e. stress)
hypothalamus –> POSTERIOR pituitary –> release of ADH –> increases blood volume for fight of flight response
s/s of metabolic syndrome, aka
Syndrome X
- abdominal obesity
- abnorm glucose metab
- increase lipids
- increase BP
- 40% of Americans
what does hypothalamus affected by, control, monitor, integrate and system is it the master gland of
affected by: phys and psych stress control: h2o balance, temp, body growth & hunger monitor: feelings of rage passion & fear integrates: response of SNS & PNS master gland: endocrine sys
in GAS what does coritsol, catecholamines and beta endorphins funx
cortisol: increase synthesis of catecholamines
catecholamines: cause insulin resistance and cardiovasc effects
beta endorphins: improves mood, increases social affiliation (oxytoxcin), decrease pain perception, can be depleted
5 general aspects of ANS
- both CNS or PNS, regulated by hypothal. nerve tracts in spinal cord, terminate at effector organs
- largely subconcious
- regulates adjusts coordinates vital visceral funxs
- affects/is affected by emotions
- 2 neuron system:
- ganglion (mass of nervous tissue made up of neuron cell bodies lying outside brain and spinal cord)
- myelinated neuron connective tissue insulation to speed conduxn
Two branches of ANS & perspective neurotransmitters
SNS: fight flight noriepi & epi, epinephrine is more potent, & ACH
PNS: rest & digest: ACH
Describe when SNS & PNS releases its different neurotransmitters using cholinergic, nicotinic, muscarinic, adrenergic
sns pns Preganglionic neurons: release ACH, cholinergic receptors (nicotinic)
PNS postganglionic neurons release ACH, cholinergic receptors (muscarinic)
Most SNS postganglionic neurons release norepi as neurotransmitter, receptors adrenergic (alpha or beta)
-sweat gland postganglionic neurons release ACH, cholinergic receptor (muscarinic)
where does nore and epi come from
norepinephrine: can be neurotransmitter or come from the medulla
epinephrine: only comes from the medulla
1st type of adrenergic receptors & location & response
alpha 1: smooth muscle of blood vessels in gut and skin cause vasoconstriction, raises BP shunts blood to lungs liver brain skeletal muscles and <3
alpha 2: located on actual nerves that stimulate effector cells & brain, located on smooth muscle of GI tract: cause relaxn decrease digestion
2nd type of adrenergic receptors & location & response
beta 1: located on (which increases BP)
Beta 2: located on bronchial smooth muscle: cause bronchodilation, also located on blood vessels in skeletal muscles: cause vasodilation, increases blood flow to muscles
