Transcript PathophyIntro

Pathophysiology
Pathophysiology / Agenda
What is pathophysiology ?
 Why do we study pathophysiology ?
 Concepts of Health and Disease
 What is the Disease ?
 Etiology of Disease
 Pathogenesis of Disase
 Outcome of Disease

What is pathophysiology? X
Pathophysiology may be defined as the
physiology of disease, of disordered function,
or derangement of function seen in disease
that is produced by the action of etiologic
agents on susceptible tissues or organs.
Pathophysiology includes also the study of the
mechanisms underlying disease.
study of the effect of disease on cell, tissue, organ and
system.
What is pathophysiology?
X

A subject to explore the rule of origin and
evolution of disease processes and the
fundamental mechanisms.

Pathophysiology can also mean the
functional changes associated with or
resulting from disease or injury
001Heart Attack / Myocardial Infarction
http://www.youtube.com/watch?v=gGY2CsFsiAk
Why do we study pathophysiology？
Pathophysiology is an important subject bridging
Basic sciences and clinical medicine.
pathophysiology
clinical
medicine
basic
sciences
bridge subject
Why do we study pathophysiology X

Enabling the students, clinicians and other
practitioners to understand why and how
diseases develop and various clinical
manifestations appear,
and what are the fundamental
mechanisms.
Other names
Also named:

Physiopathology

Physiology of Disease

Physiology of Disordered Function
Difference from Physiology X

Pathophysiology or Physiopathology is
a convergence pathology with physiology.
Pathology is the medical discipline that
describes conditions
typically observed during a disease state,
whereas physiology is the biological
discipline that describes processes or
mechanisms operating within an organism.
Difference from Pathology X

Pathology emphasizes the structural changes

Pathophysiology focuses on the functional
and metabolic alterations and
the mechanisms
Difference from Pathology X

Pathology describes the abnormal or
undesired condition, whereupon
pathophysiology seeks to explain the
physiological processes or mechanisms
whereby such condition develops and
progresses
Concepts of Health and Disease X
Health
■
The World Health Organization affirms that health is “more
than the absence of disease,” but rather a state of
“complete physical, mental, and social well-being,” This
definition sets a lofty goal for patients seeking health as
well as for health care professionals.
●Factor in health
▲ physical
▲ mental
▲ social
well-being
well-being
well-being
■
Disease X
Disease is referred as aberrant manifestation of
deregulated homeostasis caused by harmful agents.
Disease is defined as an abnormal life process which
is induced by disorders of homeostasis under the
action of certain cause(s).
●Factor in disease
▲disease
is caused by the
etiological factors.
▲base
Homeostasis
of disease is
deregulated homeostasis.
Neural regulated
deregulated
Humoral regulated
Signal regulated in cell
What is the Disease? X

It is the “State in which an individual
exhibits an anatomical, physiological, or
biochemical deviation from the normal”
•Disease may be defined as :
an abnormal alteration of structure or function in any part of the body.
Various Classification of Disease 1

Developmental – genetic, congenital.

Acquired:
*Inflammatory – Trauma, infections, immune, etc.
*Neoplastic – tumors cancers
*Degenerative – ageing.
*Metabolic.
*Iatrogenic: Drug induced.
Various Classification of
Disease 2

Anatomical



Developmental (age)






Organ
System
Neonatology
Pediatrics
Adolescent
Adult
Geriatrics
Etiological
Homeostasis


internal constancy or a stable internal environment A “body
in balance” is in homeostasis
Homeostatic regulation ---- works by using feedback loops
• Feedback loops utilize 3 components
(1) receptor
(2) control center
(3) effector
– 2 types of feedback loops
(1) negative feedback
– Restores any change back to normal
– Resembles “teeter-totter”
– Stabilizing
– Most common
(2) positive feedback
–
–
–
–
Exaggerates the change
Resembles “domino effect”
Stimulating
Least common
Disease Process

5 Components





Epidemiology
Etiology
Pathophysiology
Clinical Manifestations
Outcome
“COPE”
Epidemiology

Epidemiology

Define
 Factors:
 Predisposing,
 Precipitating
Herpes D Virus
Epidemiology X

is the study of the patterns, causes, and
effects of health and disease conditions in
defined populations. It is the cornerstone
of public health, and informs policy
decisions and evidence-base medicine by
identifying risk factors for disease and
targets for preventive medicine.
Etiology X
Concept of Etiological Factors & Predisposing
■
Etiologic factors involved in diseases include causative,
predisposing and precipitating factors, which
contributes to the onset of diseases.
●Etiological factors
▲The
factor that causes the disease and determine
the clinical features of the disease
▲Among
the etiological factors, a wide range of
extrinsic factors in the environment and intrinsic
factors in the body must be considered.
Etiology:
What is the cause?


Environmental agents:
• Physical
• Chemical
• Nutritional
• Infections
• Immunological
• Psychological
Genetic Factors:
• Age
• Genes
X
Multifactorial
As Diabetes,
Hypertension
Cancer
Etiology
Disease Disease
Disease
Disease
One
etiologic agent
one disease, as
Malaria.
• Several etiologic
agents
one
disease, as diabetes .
Disease
• One etiologic
agent
several diseases,
as smoking.
Etiological factors
Extrinsic Factors

Biological agents

Chemical agents

Physical agents

Nutritional imbalance
Etiological factors
Intrinsic Factors

Genetic factors

Congenital factors

Immunological factors

Psychological factors
Classification of etiological factors
■
●Factors of environment
▲biological
▲physical
agents
agents
▲chemical
agents
●Inherited factors
▲gene
mutation
▲chromosomal
aberration
【genetic predisposition】
The genetic mutations cause problems only when a
person is eposed to certain environmental agents.
●Congenital factors
The disorders are of a developmental nature and most
of them are nongenetic.
●Nutritional imbalance
Either excesses or deficiencies of nutrients
predispose cells to injury.
●Immunological factors
▲anaphylactic
reaction
▲autoimmune
disease
▲immunodeficiency
disease
●Psychological and social factors
Anxiety, strong or persistent psychological
stimulation or stress may lead to mental
illness and may be related to some
diseases, such as hypertension, peptic
ulcer, coronary heart disease, and
depression.
Predisposing factors
The function of these factors is to intensify the
effects of causative factors and promote the onset
and development of diseases.
Predisposing Factors X

Age




Sex



Young are prone to accidents
Getting diseases such as diabetes, heart disease,
and certain cancers increase with age
Very old are prone to drug interactions
More frequent in woman: MS, osteoporosis
More frequent in men: gout, Parkinson’s disease
Lifestyle

Examples of harmful lifestyle:





Perilous occupation
Smoking
Excess alcohol
Poor nutrition
Sedentary activity
Predisposing Factors X

Environment






Heredity


Air pollution
Water pollution
Poor living conditions
Excessive noise
Chronic psychological stress
Deals with genetic predisposition (inheritance)
 Genetic predisposition + certain type of
environment =
mental retardation , lung cancer, etc.
Preventive health care
 The best treatment of a disease is prevention !!

Deals with altering risk factors that can be changed
Predisposing factors for
colorectal Cancer
Poor diet (more fresh food, increase fiber)
 Sedantary life style
 Decreased regular physical activity
 Heredity (regular screening)
 Age (digestion slows)
COLONOSCOPY after 50

Precipitating Factors
The factors that promote the
development
of
disease
and
influences the timing of illness onset
The factors that start to outset of
disease.

Natural conditions

Physical condition

Social condition
aftershave-asthma
Pathogenesis X
The sequence events in the response of the cells or
tissues to the etiologic agent, from the initial stimulus to
the ultimate expression of the disease,”from the time it
is initiated to its final conclusion in recovery or death”
The pathogenesis of a disease is the mechanism that causes the
disease.
For example bacterial pathogenesis is the mechanism by which bacteria
cause infectious illness.
Pathogenesis X
Pathogenesis of disease refers to the rules and
mechanisms underlying the development or evolution of
diseases. It studies:
how the primary pathological agents cause disease in
organism and how the disease develops.
Basic Mechanisms of Disease
■
•Neural mechanism
•Humoral mechanism
•Cellular mechanism
•Molecular mechanism
Neural mechanism
•Neural system plays a central role in regulating
entire life activities; the disturbance occurred in
neural system and in periphery organs are mutually
affected.
•Encephalitis B virus can damage neural system
directly;
•some poisons may interrupt the metabolism of
neural cells and the production and release of
neurotransmitters.
Humoral mechanism (humoral factors, cytokines)
Humoral regulation is crucial in maintaining internal homeostasis. Humoral
dysfunction generally indicates the alterations in number and in activities of some
humoral factors( hormones, chemical mediators, cytokines). They function
through endocrine, paracrine, and autocrine to regulate the metabolism and
activities of the cells .
During the development of diseases, the regulations
in humoral and neural system are usually
simultaneous
e.g. disturbance of neural-humoral regulation in hypertension:
constant stress
--- dysfunction of neural system (cerebral cortex and hypothalamus)
---sympathetic-adrenal medulla system
----increased secretion of norepinephrine and epinephrine
--- constriction of arteries/ constriction of renal afferent arterioles will activate renin---- angiotensin-aldosterone system,
and finally causes hypertension.
Cellular and molecular mechanism
Cellular and molecular damages or alterations are fundamental in the development
of disease.
Strong acid and alkali destroy the cells with no selection;
hepatitis virus damages specifically the hepatocytes.
•Disease genomics:
Disease proteomics
Pathophysiology Focus

Disease Mechanisms





Genetic
Internal
External
Pathogenesis
Morphology


Gross
Histological
Morphology: X
Structural
disease.
changes in
Tumor
in a cancer.
Ulcer in an infection.
Atrophy in dementia.
Gross
& Microscopic.
■
General Rules for Pathogenesis of Diseases
●Damage and anti-damage responses
Damages are usually made when a variety of harmful
insults attack the body.
During this process, anti-damage responses are
also induced in the body to restore the normal
situation.
Severe burn
pain
InfectionDamage
(fever)
plasma loss
shock
ischemia & injury of Cells
Bp↓, blood volume↓
Stress
WBC↑, Blood coagulation↑
SAMS excitation(+)
Anti-damage
Anti-infection↑, plasma
loss↓
C.O↑, Blood redistribution
Rehabilitation
blood flow heart & brain↑
SAMS: Sympathetico-adrenal-medullay system; c.o: cardiac output
Clinical Manifestations X

Symptoms /Syndrome




Signs




Patient Report
Subjective
Related Terms: Prodromal,
Insidious, Latent
Health care exam
Observable phenomena
Objective
Diagnostic Criteria



Laboratory results
Imaging
Biopsy
Digital Thermal Imaging
Clinical Manifestations
Displaying clues and symptoms of an
illness
 Clinical manifestations are the
observable symptoms by which a disease
may be diagnosed by a physician.
 It is how a disorder 'manifests' itself to an
observer.

What is Osteoarthritis: Signs & Symptoms
http://www.youtube.com/watch?v=YLB11LJF5Vk
Signs & Symptoms
Relating to disease, noticable or
preceptible interpretation of modified
health condition
 A signal that is expressed by an ill
individual and is often considered a
personal meaning

Signs vs symptoms X
Signs are the physical
manifestation of
injury, illness or
disease.
 A high temperature
a rapid pulse,
low blood pressure,
bruising can be called
as signs



symptoms are what a
patient experiences
about the injury,
illness or disease
Chills, shivering,
fever, nausea,
shaking and vertigo
are the symptoms.
Pneumonia signs & Symptoms
Flu like
 Persistent cough
 Fever
 Shortness of
breath
 Chest pain
 Chills
 sweath

Cough, with thick,
sticky fluid
 Fatigue and
muscle aches
 Nausea, vomiting
or diarrhea
 Headache

Common symptoms (Diabetes)










Frequent urination
Excessive thirst
Unexplained weight loss
Extreme hunger
Sudden vision changes
Tingling or numbness in the hands or feet
Feeling very tired much of the time
Very dry skin
Sores that are slow to heal
More infections than usual
• Latent symptoms: Existing or present
but concealed or inactive.
X
Prodromal symptoms: An early symptom
indicating the onset of an attack or a
disease.
 Insidious/Vague symptoms: There are a
number of diseases, some of them very
serious, which only cause mild or vague
symptoms. People may not even really
feel sick, but just have a feeling that things
are not quite right.

Asymptomatic X

Absence of any observable symptoms
even though lab tests announce a disease
is present
The course of a disease X
An acute disease has relatively sudden
onset and lasts for a short term,
 a chronic disease, sometimes begins with
an acute phase, usually lasts for a long
period of time.
 subacute

Eczema-Dermatological Definition

An acute, subacute but usually chronic
pruritic inflammation of the epidermis and
the dermis, often occurring in association
with a personal family history of hay fever,
asthma, allergic rhinitis or atopic
dermatitis.
Characteristics of Acute Eczema

Well demarcated plaques of erythema
and edema on which are superimposed
and closely spaced small vesicles filled
with clear fluid with punctate erosions and
crusting

Distribution may be isolated and localized
or general
Acute Eczema
Note the erythema, vesicles and swelling
Characteristics of Subacute
Eczema

Plaques of mild erythema with small dry
scales and or superficial desquamation,
sometimes associated with small red,
pointed or round papules

Distribution may be isolated and localized
or general
Subacute Eczema

Note erythema, swelling and desquamation
tion
Characteristics of Chronic Eczema

Plaques with deepening of the skin lines
with satellite, small, firm flat or round top
papules, excoriations and pigmentations
or mild erythema
Chronic Eczema

Note lichenification, scaling and fissuring
Acute - Subacute - Chronic
Swelling and erythema
Punctate erythema,
desquamation
Lichenification
Outcome

Expected


Prognosis
Actual



Cure
Remission
Exacerbation
 Complication
 Palliative
 Death
Prognosis X

Expected outcome of the disease, It is the clinician's
estimate of the severity and possible result of a
disease.
Outcome of disease X
 Complete
recovery
 Incomplete
 Death
recovery
Outcome X
Cure: Restoration of health; recovery from
disease
 Remission: A period during which
symptoms of disease are reduced (partial)
or disappear (complete remission)
 Exacerbation: An increase in the severity
of a disease or in any of its signs or

Outcome X
Complication; secondary disease or
condition that develops in the course of a
primary disease or condition and arises
either as a result of it or from independent
causes.
 Palliative: Medications and treatments are
said to have a palliative effect if they
relieve symptoms without having a
curative effect on the
underlying disease or cause

Complete recovery
The best outcome of a disease:
•the etiological factors disappear
•the pathologically altered metabolism, structure and
function are perfectly restored
•the symptoms and signs of the disease disappear
entirely
• homeostasis is recovered
Incomplete recovery
The main symptoms and signs disappear but
some pathological changes are left behind, namely
sequela.
Sequela is generally brought about by the
compensatory response to maintain a relatively
normal activity.
For example, the permanent damage to the
heart valve after rheumatic fever.
Death
■
The cessation of heart-beats and breath is used as the
criterion of death of a body.
●Brain death
The functions of cerebrum and brain stem stop forever.
Brain Death (WHO criteria ) X

Cessation of spontaneous respiration

Irreversible coma

Absence of cephalic reflexes and dilated pupils

Absence of any electrical activity of the brain

Absence of brain blood flow
Terms Used In Pathophysiology X



Pathology = study of disease
Pathogenesis = the development of a disease
Diseases develops in stages
 Infectious disease example:
(A)incubation (b)disease (c)convalescence




Pathophysiology = the study of the functional changes
associated with a specific disease
 How the disease affects specific functions of the
body
Subjective findings
 The patient’s symptoms
 Described by the patient----(the patient’s history)
Objective findings
 Health provider’s findings---( the physical exam)
Occurrence of disease defined by 2 factors


Incidence = # new cases per unit of time
Prevalence = # new & old cases per unit of time

Disease terminology X















Etiology = cause of the disease
Idiopathic = disease with unknown cause
Iatrogenic = disease caused by human intervention
Congenital diseases = diseases occurring at birth
Syndrome = common cause of different signs & symptoms
Remission = period when symptoms & signs of disease abates
Exacerbation = period when symptoms & signs increase
Endemic disease = disease native to local area
Epidemic = many people affected in a given area
Pandemic = many people affected in large areas
Incubation = latent period of the disease before develop signs
& symptoms
Prognosis = probability for recovery
Morbidity = disease rates within a group
Mortality = death rates within a group
Epidemiology = how the disease occurs & spreads through an
area
I hear, I forget
I see, I remember
I do, I understand
Chinese Proverb..