Pathophysiology Introduction:

Chapter 1:
Under ideal circumstances our bodies work beautifully.
When our internal environment is stable, it is called homeostasis.
When homeostasis is interrupted or cannot be maintained, we have disease.
Simplistic, yes, but true.
The body is a system so disruption in one area can easily interfere with another.

Homeostasis



***Disorders affecting a particular system or organ display a common set of signs and symptoms related to the failure of that organ’s normal function.

Examples:
What might we expect if we had a liver malfunction? Kidney (Renal), Cardiac, Respiratory…

Today some of the current health initiatives focus on prevention:
Medical Homes
Screenings
Immunizations

Research to develop a technology to limit or prevent disease:
1st basic science laboratory, animals or cells
2nd trial with a small number of human subjects
3rd large clinical trials, double blind
If merit is demonstrated after the 3 steps these are considered evidence based trials

Think about it…?s
What might be a reason to stop a trial prematurely? Ex. AZT (antiretroviral agent)
What is ‘off label’ use?
What other issues affect research?

The Language of Pathophysiology:
Abnormalities can be at the system or organ level but also the microscopic level, these can be found with biopsy or autopsy

Diagnosis - involves evaluation of S&S, labs, radiographs, other tests or procedures

Etiology - causative factors, genetic, congenital, viruses, bacteria, immunologic disorder, metabolic or degenerative changes, trauma or nutritional disturbances

If the cause is unknown it is idiopathic
If the cause is from an error, treatment or procedure it is iatrogenic, examples…
Risk versus benefit

Predisposing factors - at risk for development of disease
Prevention - vaccinations, diet
Pathogenesis - development
Onset of the disease may be acute, sudden, obvious or insidious, slow and gradual
Acute - is short term, quick
Chronic - is milder, developing gradually and lasting a long time
Subclinical - means no obvious manifestations of disease are exhibited
Latent phase - is silent with no clinical signs, incubation period.
Prodromal period - signs and symptoms but negative tests difficult to diagnose
Manifestations - signs and symptoms, clinical effects
Signs – objective indications obvious to others
Symptoms – subjective feelings of the client
Lesion – a localized change in tissue
Syndrome – collection of signs and symptoms
Remission – manifestations of disease subside
Exacerbation – manifestations flare up
Precipitating factor – trigger
Complication – secondary problem that arises after initial condition
Therapy – treatment measures
Sequelae – unwanted outcomes from a disease or injury
Convalescence or rehabilitation – period or recovery
Prognosis – probability or likelihood of recovery
Morbidity – disease rates within a group
Mortality – death rate from a particular disease
Epidemics – higher than expected number of infections in an area
Pandemics – higher numbers across the globe
Occurrence – measured by incidence and prevalence
Incidence – number of new cases
Prevalence – number of new and old cases
Communicable – spread person to person
Notifiable or reportable – must be reported by a physician to authorities, DHEC
Autopsy or postmortem exam – examination of body by pathologist after death to find cause of death
Diagnostic tests – laboratory, radiologic, tests to examine tissues, cells, or chemically analyze body fluids. These are ordered based on clinical examination and patient history

Cellular terminology:
Atrophy – decrease in cell size, decreased tissue mass
Hypertrophy – increase in the size of cells, enlarged tissue mass
Hyperplasia – increased number of cells, enlarged tissue mass
Metaplasia – one mature cell type replaced by another mature cell type
Dysplasia – cells vary in size, shape, large nuclei, rate of mitosis increased, chronic
Anaplasia – cells undifferentiated, variable nuclear, cell structures, mitotic changes
Neoplasm – new growth, tumor, cancer,
Apoptosis – programmed cell death, normal, may increase due to disease
Ischemia – decreased supply of oxygenated blood to a tissue or organ
Hypoxia – reduced oxygen in tissue
Anaerobic – absence of oxygen
Exogenous – chemicals in the environment
Endogenous – chemicals in the body
Lysis – dissolution, disintegration of cell releasing lysosomal enzymes into tissue
Inflammation – swelling, redness, pain, damage to nearby cells and loss of function caused by cell lysis
Necrosis – when a group of cells die
Liquefaction necrosis – process by which dead cells liquify
Coagulative necrosis – cells retain form but not function after death
Fat necrosis – fatty tissue is broken down into fatty acids, infections or enzymes
Caseous necrosis – coagulation necrosis thick, yellowish, cheesy substance, TB
Infarction – area of dead cells, heart
Gangrene – area of necrotic tissue invaded by bacteria

References:

Gould, B. E., & Dyer, R. M. (2011). Pathophysiology for the health professions (4 ed.). St. Louis, Missouri: Saunders Elsevier.


Story, L. (2012). Pathophysiology: A practical approach. Sudbury, MA: Jones & Bartlett Learning .

Videos:

Homeostasis
http://youtu.be/QKT47A-LBj4