*Intro to Patho*
Define validity, reliability, & predictive value in relation to diagnostic testing. - ✔️✔️-
validity (accuracy) = degree to which a measurement reflect the true value of the object
it's intended to measure
- reliability (precision) = ability of a test to give the same result in repeated
measurements
- predictive value = extent to which a test can differentiate btwn the presence/absence
of a condition
*positive PV = estimate of the probability that the disease is present if the test is positive
*negative PV = estimate of the probability that the disease is absent if the test is
negative
What are the specific stages of clinical manifestations? - ✔️✔️> latent period = from
exposure to injurious agent to 1st appearance of S/Sx (aka incubation period for
infectious disease)
> prodromal period (prodrome) = appearance of S/Sx & onset of disease
> manifest illness (acute phase) = disease at full intensity w most severe S/Sx
- silent period(s) = when S/Sx ease/disappear before returning
- subclinical stage = when pt functions normally even though disease processes are
established
> convalescence = recovery after disease, injury, or operation
Ex: Explain the pathophysiology of type I diabetes mellitus (4 components) - ✔️✔️1.
Etiology > autoimmune destruction of pancreatic B cells
2. Pathogenesis > insulin deficiency > disturbed metabolism of carbs, proteins, & fats
3. Clinical Manifestations > polyuria, dehydration, macro/micro vascular lesions
4. Treatment > maintaining normal blood sugar levels
What is pathophysiology? - ✔️✔️study of abnormalities in physiologic functioning of
living beings & the physiologic responses of an organism to disruptions in it's internal &
external environ
How is pathophysiology different from pathology & physiology? - ✔️✔️- pathology =
study of causes/effects of diseases
- physiology = study of normal functions of living organisms & their parts
What are the 4 components of pathophysiology? - ✔️✔️1. Etiology
2. Pathogenesis
3. Clinical Manifestations
4. Treatment
,1. Etiology - ✔️✔️study of causes/reasons for phenomenon, disease, & injury
*often difficult to pinpoint bc of role of genetics & environ
What is meant by idiopathic? Ex? - ✔️✔️= disease/condition is of unknown cause
> ex: chronic fatigue
What is meant by iatrogenic? Ex? - ✔️✔️= disease/condition caused by unwanted or
unintended medical intervention > ex: hair loss caused by chemo therapy
What is meant by risk factor? - ✔️✔️= factor that when present incr the risk for disease
2. Pathogenesis - ✔️✔️= development of disease from initial stimulus to expression of
manifestations of the disease > ex: direct effects of initiating event, physiological
responses, & compensatory mechanisms
3. Clinical manifestations
Signs, Symptoms, & Syndromes? - ✔️✔️= signs & symptoms (S/Sx)
- S = objective, observable manifestations of the disease
- Symptoms = subjective feelings of abnormality
- Syndrome = disorder that the etiology of S/Sx has not been determined for yet
Define sequela & complication - ✔️✔️- sequela = pathological chronic condition
resulting from the disease
- complication = new/separate acute process caused by a change produced by the
original problem
Define exacerbation & remission - ✔️✔️- exacerbations = incr severity of S/Sx
- remissions = decr severity of S/Sx
*diseases often undergo alternating exacerbations & remissions
*cured = 5+ years of remission
What are the 2 clinical courses of conditions/diseases? - ✔️✔️1. acute condition =
severe manifestations but short course (hr/days/wks)
2. chronic condition = develop either w a prolonged acute phase or gradually without an
acute phase (months-years)
Ex: What are some possible treatments for diabetes? - ✔️✔️regular blood sugar level
monitoring, insulin therapy, diet & lifestyle changes (exercise)
How do we determine health & disease? - ✔️✔️we use diagnostic testing & statistical
normality to identify normal & abnormal variation
,What do we use to compare health & disease? - ✔️✔️= normal distribution/the "bell
curve" (using a large sample of a pop. to give a good estimate of the "normal" values in
that pop.)
- normal range = mean +/- 2 standard deviations > ex: 5% of the normal pop. may fall
outside the normal range w/out demonstrating disease
*change in invid's factor is more important than the actual value of the factor (pts
evaluated 2-3x to establish baseline)
How do we determine if a specific condition is present? - ✔️✔️1. clinical examination =
to develop probabilities (possible explanations)
2. order laboratory & diagnostic testing = to identify most likely probability
Define sensitivity in relation to diagnostic testing - ✔️✔️= probability the test will be
positive when applied to a person w the condition
ex: 80% sensitivity > 20% (false-negative rate) of the group with the condition would
wrongly test negative
How do we determine that the tests we use to collect data from our pts have reliability,
validity, & predictive value? - ✔️✔️high sensitivity + high specificity + individ w a high
probability of having the condition = better predictive value
How are individuals different in their expression of a disease? - ✔️✔️= individ factors
can vary!
- culture
- age
- gender
- situational > ex: adaptation to altitude
- time variations > ex: time of day
Ex: Explain how heart rate varies depending on pt age. - ✔️✔️*avg = 60-100 bpm
- 20 yo = 100-170 bpm
- 40 yo = 90-153 bpm
- 60 yo = 80-136 bpm
Ex: Explain how a strep throat test meets the criteria for reliability & validity. - ✔️✔️
Define epidemiology - ✔️✔️= study of patterns of disease involving aggregates of ppl
*provides us w info on occurrence, incidence, prevalence, transmission, & distribution of
diseases throughout pops!
Differentiate btwn endemic, epidemic, & pandemic. - ✔️✔️- endemic = disease native
to a local region
- epidemic = disease disseminated to many individs at the same time
, - pandemic = epidemics that affect large geographical regions
Define aggregate factors. Ex's? - ✔️✔️= principal factors that affect the patterns of
disease in human pops
- age
- ethnic group
- gender
- socioeconomic factors (SES) & lifestyle
- geographic locations
How does WHO define health? - ✔️✔️= complete physical, mental, & social well-being
(NOT just the absence of disease/infirmity)
What are the levels of prevention? Ex's? - ✔️✔️1. Primary = altering susceptibility &
reducing exposure for susceptible individs
> ex: improving sanitation/housing/nutrition, incr immunization coverage, & health
education/promotion
2. Secondary = early detection, screening & management of disease (applicable in early
disease stages)
> ex: annual physicals/screenings & new prenatal techniques
3. Tertiary = rehabilitative/supportive care & efforts to alleviate disability & restore
effective functioning (applicable in advanced disease/disability stages)
> ex: surgical or medical treatment (pharmacotherapy, PT, radiation, etc...)
*Stress & Adaptation* - ✔️✔️
Define homeostasis - ✔️✔️= maintaining internal conditions in a stable state by
keeping parameters relatively the same (state in which all systems are in balance
around an ideal "set-point")
Define allostasis - ✔️✔️= dynamic process that supports & helps the body achieve
homeostasis using various regulatory processes controlled by the brain (constant
reevaluation & readjustment of the body's parameters according to the individ's
situation)
Define stress, stressor, & stress response - ✔️✔️- stress = real/perceived threat to the
balance of homeostasis
- stressor = anything that throws the body out of allostatic balance
- stress response = body's effort to restore the balance
Hans Selye's Study of Stress Response (1936) - ✔️✔️= found the link btwn biology &
stress after experimenting with rats & finding that any kind of harmful physical stimuli
(injections, temp. extremes, surgery) produced the same observed physiologic changes
*Termed...
- stressors = harmful stimuli/causative agents & general