Fundamentals of Pathophysiology
The Basis of Disease in the Human Being
Pathology 101
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Under normal conditions, the body tries to maintain
internal stability
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Homeostasis
When homeostasis is not maintained, disease ensues
Pathologists study these diseases
There are two specializations within the field
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Anatomic Pathology: performs autopsies to determine cause
of death
Clinical Pathology: review lab specimens to determine evidence
of abnormal tissue or the presence of chemicals
Pathogenesis
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The sequence of events that leads from
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Ex.: Common Cold
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Cause of disease to structural and functional abnormalities
How the disease manifests itself
Resolution or recovery of the disease
Cause: exposure and inoculation of the cold virus
Incubation time: virus multiplies
Manifestation: host begins to have signs and symptoms
Recovery: return to the previous state of health
Usually explained in terms of time
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Acute disease: disease of sudden onset which runs a severe but short
course
Chronic: long-term illness, possibly reoccurring
Risk Factors: Age
Elderly
Newborns
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Immature immune system
Liver enzymes lacking
Fewer nutritional reserves
Less body fat to insulate
against cold
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Decrease in immune
function
Decline in homeostasis
mechanisms
Depression, isolation and
malnutrition
Risk Factors: Sex
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Some diseases are more
prone to strike one
gender than the other
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Men or more prone to
develop gout
Women are more likely to
develop osteoporosis
Risk Factors: Misc.
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Genetic Makeup
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Stress
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Increases production of corticosteroids, which decrease
immune system function
Lifestyle
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Diabetes, asthma, migraines
Personal habits: alcohol consumption, sexual practice, smoking
Occupation
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Exposure to loud noises, pollutants, repetitive movements
Risk Factors: Misc., cont.
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Preexisting illnesses
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Illnesses can lower the body’s resistance and make individuals
more susceptible to other diseases
Chronic illness interferes with the proper function of some
body systems; therefore complicating disease
Environmental exposure
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Prolonged exposure to cold or heat can lower the body’s
resistance
Exposure to allergens
Long-term exposure to sunlight
Long-term exposure to occupational chemicals
Disease Categories: Structural Disease
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Involves physical and
biochemical changes within the
cells
Structural changes in cells are
initiated by two types of agents
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Exogenous – those that are
external
Ex.: trauma, chemical injury, and
microbial infections
Endogenous – those that are
internal and diseases that are a
result of abnormal metabolism
Ex.: vascular insufficiency,
immunological/autoimmune
reactions
Disease Categories: Structural Disease
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The hallmark
characteristic of structural
disease is the lesion.
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A widely used term to
describe many types of
cellular changes that result
in tissue abnormalities
(cuts, fractures, masses,
etc.).
Primarily detected by
observation with the naked
eye or with a microscope.
Disease Categories: Functional Diseases
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Diseases in which the
onset begins without the
presence of any lesion
The basic change is
physiological
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Referred to as a
pathophysiological change.
Examples
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Tension headaches and
functional bowel syndrome
Effects of Structural and Functional Diseases
Disease
Type of Disease
Nature of Manifestation
Common cold
Structural: viral infection
Structural: runny nose and
sneezing
Tension Headaches
Functional: muscle spasms
Functional: pain
Benign tumor that
produces mass
Structural: tumor
Structural: mass
Exogenous obesity
caused by craving food
Functional: hunger
Structural: obesity
Cancer of the
esophagus
Structural: cancer
Functional: inability to eat
Causes of Disease: Infectious Agents
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Caused by invasion and
colonization of pathogenic
microorganisms
Examples of pathogenic
infection
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Fungal infection
Bacterial infection
Viral infection
Causes of Disease: Immunologic
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Hypersensitivity
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Immune Deficiency
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Overreaction by the
immune system
Underreaction by the
immune system
AIDS
Autoimmune
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Destruction of one’s own
tissues by antibodies
produced by one’s own
immune system
Causes of Disease: Nutritional
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Diseases created by
insufficient resources for the
body
Protein deficiency
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Vitamin or mineral
deficiencies
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Difficulty in healing or
formation of new body tissue;
decrease in antibody
production
May lead to interference in
biochemical reactions of
metabolism
Obesity
Causes of Disease: Metabolic
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An upset in the
biochemical reactions that
govern body processes or
metabolism
Sub-classified as
nutritional
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Upset is often connected
to carbohydrate, fat, or
protein metabolism
Causes of Disease: Genetic
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Inherited or hereditary
diseases
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Due to transmission of
defective gene(s) or
chromosome(s) from one
or both parents
Ex.: diabetes, Down
Syndrome, hemophilia,
cleft lip
Causes of Disease: Congenital
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A defect in fetal
development that may
create a functional
(physiologic) or structural
(physical) abnormality
which presents itself at
birth
May be
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Genetic
Exposure to chemicals,
drugs, or viruses during the
pregnancy
Spontaneous event
Causes of Disease: Trauma
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A physical force that
mechanically disrupts the
structure of the body (and
therefore, disrupts body
function)
Generally referred to as
injuries
Ex.: bruises, abrasions,
cuts, fractures, burns, etc.
Disease Process: Manifestation
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How a disease “presents or shows itself.”
Also called clinical presentation
Includes both signs and symptoms.
Signs
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Objective physical observations as noted by the person who
examines the patient
Referred to as physical or physical examination
Ex.: temperature, blood pressure, respiratory rate, abnormal heart
sounds, mass, enlarged organs, edema
Symptoms
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Patient’s awareness of abnormalities or discomfort
Not measurable and are based on the patient’s subjective
perceptions
Ex.: pain, nausea, weakness, fatigue, and dizziness
Disease Process: Manifestation
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During the physical, the health professional may use
techniques such as
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Inspection (looking at or observing areas of the body)
Auscultation (use of a stethoscope to listen to body cavities)
Palpation (feeling lightly or pressing firmly on internal organs
or structures)
Percussion (tapping various body areas to produce a
vibrating sound indicative of air, fluid, size of organ, etc.)
Olfaction (using smell to note abnormalities)
Disease Process: Care of the Patient
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Involves three major steps
Obtaining a history
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Determines patient’s symptoms
Review any past or present medical problems that might relate
Performing a physical examination of the patient
Laboratory tests, and radiologic and clinical procedures
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Detects chemical and physiologic abnormalities to aid in
establishing the diagnosis
Disease Process: Etiology
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Study of causes of a disease
Idiopathic
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Latrogenic disease (-iatro = medicine, physician)
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Cause of the disease has never been discovered
One may also refer to an idiopathic disease as having
“unknown etiology.”
Disease arose as a result of a prescribed treatment
Ex.: Immunosuppression and/or anemia as a result of
chemotherapy
Healthcare Acquired
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Disease acquired from a clinical setting
Ex.: A child develops a cold after being exposed to other sick
children at the pediatrician’s office
Disease Process: Diagnosis
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The process of assigning a
name to a patient’s
condition
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Needed to determine the
treatment and potential
outcome of a disease
Syndromes
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Clusters of findings with
more than one disease
Disease Process: Treatment
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Should be as precise as possible in order to attempt a
cure.
Treatment interventions may include exercise, nutritional
modifications, physical therapy, medications, surgery, and
education.
There are three types of treatment
Supportive Therapy
 Includes rest, optimal nutrition, fluids, and possibly
antibiotics to prevent a secondary infection while the
immune system is recovering
Disease Process: Treatment
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Palliative Therapy
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Not a healing therapy
Provides relief from signs and symptoms of a disease
Ex.: steroids, pain relievers, possible surgery
Used for terminal illness and other serious chromic conditions
for which there is no cure
Preventive Therapy
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Care given to prevent disease
Ex.: mammograms, BP screenings, routine dental care
Disease Process: Prognosis
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Predicted or expected
outcome of the disease
Often listed as
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Good: full recovery
Guarded: full recovery may
or may not occur
Poor: not expected to
recover
Misc. Terminology
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Communicable Disease
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Epidemic
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Disease that spreads throughout the body or to many system
Asymptomatic
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Disease confined to one area of the body
Systemic Disease
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Disease that appears to be native to a specific area or region
Localized Disease
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Disease that affects many people in a given region at the same time
Endemic
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Disease transmitted from one person to another
No noticeable symptoms
Self-Limiting Disease
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Disease that does not require treatment to be cured