subclinical state
pathological changes occur in tissue or organ, patient displays no signs or symptoms
latent (silent) stage
no clinical signs are evident
incubation period
time period from exposure to the onset
prodromal period
early development of disease with nonspecific signs or symptoms
manifestations
signs and symptoms of a disease, local or systematic
remission
manifestations of a disease subsides
exacerbation
manifestations worsen
precipitating factor
triggers acute episode
sequelae
potential, harmful outcomes of the primary conditions
prognosis
probability for recovery or other outcomes
morbidity
disease rates within a group and the functional impairment associated with certain conditions
mortality
number or deaths resulting from particular disease
epidemiology
science of tracking a pattern or occurrence
epidemics
higher than expected number of cases in a given area
pandemics
higher than expected number of cases around the globe
incidence
new cases of a disease in specific time and place
prevalence
new and existing cases in a specific time and place
communicable diseases
spread from one person to another
notifiable diseases
disease that must be submitted to designated authorities (AIDS, SARS)
atrophy
decrease in size of cells, reduced tissue mass
ex. arm in cast
hypertrophy
increased size of cells, enlarged tissue mass
ex. weightlifting
hyperplasia
increase number of cells, enlarged tissue mass, happen at same time with hypertrophy
ex. uterine enlargement during pregnancy
metaplasia
one mature cell type is replaced by different mature cell type, may be adaptive mechanism
ex. cigarette smokers
dysplasia
cells varying in size or shape, large nuclei, increased mitosis
ex. pap smear, screening test
anaplasia
cells that are undifferentiated with variable nuclear and cell structures or numerous mitotic figures
ex. present in cancer cells, determine degree of aggressiveness
neoplasm
new growth, referred to as tumor
apoptosis
programmed cell death, normal occurrence
mechanisms of cell damage
ischemia-decreased blood supply to organ
physical agents-excessive heat or cold
mechanical damage-pressure or tearing
chemical toxins
microorganisms-bacteria, viruses
abnormal metabolites
nutritional deficits
imbalance of fluids or electrolytes
hypoxia
decreased oxygen in tissue
What are microorganisms?
bacteria, viruses, fungi, parasites
initial cell damage
alteration in metabolic reaction, which leads to loss of cell function, is reversible
subsequent cell damage
amount of damage increases, cell swells and dies, this is irreversible
necrosis
cell death
liquefaction necrosis
enzymes liquify the dead cells
coagulative necrosis
cell proteins are denatured, but the cell retains structure for period of time
fat necrosis
fatty tissue is broken down in to fatty acids, as a result of infection or enzymes
caseous necrosis
form of consultive necrosis, contains thick yellowish, "cheesy" substance
infarction
area of dead cells resulting from lack of oxygen
ex. acute myocardial infarction-death of a portion of heart muscle
gangrene
necrotic tissue that has been invaded by bacteria, can occur after infarction, must be removed surgically
brains cells die how fast?
4-5 minutes when deprived of oxygen
heart muscles die how fast?
30 minutes when deprived of oxygen
brain death
lack of response to stimuli, EEG changes, decreased perfusion (blood flow) to brain
pathophysiology
study of functional or physiological changes in the body from a disease process
pathology
study of cells and tissue changes associated with a disease
disease
deviation from the normal state of health or wellness
stages (3)
1. basic science- identify tech
2. limited clinical trials
3. large scale, clinical trials
-double blind
double blind studies
subjects and administers do not know if subject is receiving standard, proven treatment or treatment being tested
diagnosis
identification of specific disease through the evaluation of test
etiology
causative factors of a disease
ex. congenital, inherited, microorganisms etc.
idopathic
cause of disease is unknown
iatrogenic
treatment, procedure or error may be cause of disease
predisposing factors
factors that may promote but not guarantee the development of disease
pathogenesis
development of disease or sequence of events involved
acute onset
short, sudden, severe
insidious
slow, gradual with mild signs
chronic onset
mild and persistent over time