1. Pathophysiology is the study of the underlying mechanisms by which diseases occur and the changes that develop within the body. It focuses on alterations in function and metabolism and provides a basis for disease prevention, diagnosis, and treatment. 2. Pathophysiology emphasizes disruptions to homeostasis, alterations in structure, function, and metabolism that can lead to disease. It explores the developmental processes of diseases and the mechanisms involved. 3. Pathophysiology plays an important role in bridging basic medical sciences and clinical medicine by linking normal body functions to disordered states.

1. Nutritional and Genetic Mechanisms
Pathophysiology
By: Dr.Faisal
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2. Content of pathophysiology
Systemic and organic pathophysiology
Fundamental pathological process
General concept of disease
Pathophysiology in diseases
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3. Pathophysiology
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Bridge course
Basic medicine Clinical medicine

4. 1. Nature and Aims of Pathophysiology
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Basic medicine ―→ Clinical medicine ―→ Practice
―→ Qualified doctor
Pathophysiology is one of basic medical
sciences, which focus on sick or disordered
life.

5. Pathophysiology Physiology
Different targets
Normal body
Sick body
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6. Basic medical courses
normal body
structure
disordered body
structure
function
metabolism
function
metabolism
Pathoanatomy
Pathophysiology
Anatomy
Biology
Histology
Physiology
Biochemistry
about drugs----Pharmacology
Clinical medical courses
Internal medicine, Surgery, Pediatrics, et al.
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7. Pathophysiology Pathoanatomy
Different Points
Function
Metabolism
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Mechanism
Structure

8. Pathophysiology is the study of the underlying
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mechanisms occur and
by which diseases
the study
develop, and
diseases within the body.
of the changes by
It provides a
theoretical basis for the prevention, diagnosis
and treatment.

9. Pathogenesis of disease
Pathogenesis of disease refers to the rules and
mechanisms underlying the development or evolution of the
diseases.
General rules for pathogenesis of disease
Disruption of homeostasis
If homeostasis is disrupted by a variety of harmful
agents, the body cannot function optimally, and illness
may occur.
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10. Structure
Intact body
Function Metabolism
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11. Alterations
in structure
Disease
Alterations
in function
Alterations in
metabolism
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12. Pathophysiology emphasizes the
developmental process of diseases.
Disruption of the body’s homeostasis;
Alterations in function, metabolism
Mechanisms involved.
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13. Summary
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1.Pathophysiology is one of basic medical sciences which
study the rules of origin and evolution of diseases and
the underlying mechanisms --- “the physiology of
disease”.
2. Pathophysiology focuses on the alterations in function
and metabolism of the body and the mechanisms
underlying the development of diseases.
3. Pathophysiology plays an important role in bridge
linking basic medical sciences to clinical medicine.

14. General Concepts of Diseases
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15. Basic Concepts
 Health
⮚No diseases or infirmity. (Physical or mental weakness).
⮚A state of complete well-being of all aspects: physical,
mental, social.
 Disease
⮚ Disease is an abnormal life process caused by certain
pathogenic factors, deviation from the normal status
including structure, function or metabolism.
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16. Cause
Conditional factors
Body
Disease
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17. ⮚Disease is a disordered state of the body due to
pathogenic agents-host interactions.
Homeostasis: the process that the internal
environment of an organism tends to remain
balanced and stable, which is required for
optimum functioning.
⮚ Disease can be viewed as a disturbance of
homeostasis.
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18. Manifestations of diseases:
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1) Symptom: a subjective complaint
2) Sign: a manifestation that is noted by an
observer, doctor or nurse, through physical
examination, e.g. an elevated body temperature.
3) Laboratory finding: alterations found by
laboratory test, X-ray examination (routine or
CT), electrocardiogram (ECG),
ultrasonography, magnetic resonance imaging
(MRI), etc.

19. Sub-health
There is a situation, in which the person does
not show specific symptoms and signs of illness,
but lives a low-quality of life both physically
and mentally; this is called “sub-health”.
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20. Sub-health
75%
Health
5%
Disease
20%
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21. Two very important concepts
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1) Pathological Process
A series of structural, functional and metabolic
changes that appear in different diseases, e.g.
fever, inflammation, edema, etc.

22. Pathological Process and Disease
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Disease Cause Site Fundamental
Pathological Process
Pneumonia Pneumococcus Lung Fever, inflammation,
hypoxia, acid-base
disturbances, shock
Dysentery Dysentery
bacilli
Intestine Fever, inflammation,
water and electrolytes
disturbances, acid-base
disturbances, shock
Epidemic
meningitis
Meningococcus Meninges Fever, inflammation,
DIC, shock

23. Shocks
What are the 4 types of shocks?
 Hypovolemic shock (caused by too little blood
volume).
 Anaphylactic shock (caused by allergic reaction).
 Septic shock (due to infections)
 Neurogenic shock (caused by damage to the nervous
system)
Shock is a critical condition brought on by the sudden drop in
blood flow through the body.
Shock may result from trauma, stroke, blood loss, an allergic reaction,
severe infection, poisoning, severe burns or other causes. When a
person is in shock, his or her organs aren't getting enough blood or
oxygen.

24. 2) Syndrome
A set of signs and symptoms that occur
together and are characteristics of a group of
diseases or a specific disease, e.g. MS, AIDS
etc.
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25. Etiology of Disease
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Etiology is a science to study the factors
associated with or involved in initiation and
development of diseases. According to their
different roles in the development of diseases,
these pathogenic factors are classified into
cause of disease and conditional factors.

26. Causes of diseases are the factors that provoke
or cause the particular disease. It determines
the characteristics of the disease and is
absolutely necessary for disease to occur.
Conditional factors are the factors that do not
cause disease directly but rather influence the
pathogenesis of the disease.
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27. Precipitating factors belong to conditional
factors that promote the development of
diseases by enhancing the roles of cause of
diseases or susceptibility of the body to diseases.
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28. e.g. Infection, arrhythmias, pregnancy, water-
electrolytes and acid-base disturbances are
precipitating factors of heart failure
Tubercle bacillus is the cause of tuberculosis.
Not all people who inhale the organism will
suffer from pulmonary tuberculosis, which
occurs in malnutrition, over fatigue and long-
term depress.
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29. Causes of diseases
Extrinsic Factors Biological agents
Physical factors
Chemical factors
Nutritional factors
Pathogenic factors
Intrinsic Factors Genetic factors
Congenital factors
Immunological factors
Psychological factors
Conditional factors Body condition
(predisposing factors) Nature condition
Social condition
Precipitating factors
of diseases
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30. Controlling conditional factors is easier than
eliminating the causes.
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31. Causes of Disease
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1) Biological agents bacteria, viruses,
2) Physical factors: trauma and fracture, heatstroke.
3) Chemical factors
Corrosive chemicals such as strong acid and bases can
destroy cells at the site of contact. Cell-injurious chemicals are
often called toxic substances or poison. They induce tissue
and cell damage when they enter the body through certain
pathways and reach a sufficient amount. These called
intoxication or poisoning. The toxic substances often act on
specific cells or organs, e.g. CO poisoning.
Electrical injuries

32. 4) Nutritional factors
Excesses: high lipids and carbohydrates
diet obesity, atherosclerosis, diabetes
Deficiencies: lack of certain elements in diet
(1) Vitamin B: beriberi
(2) Vitamin A: night blindness
(3) Vitamin C: scurvy
(4) Vitamin D: rickets
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33. Intrinsic Factors
1) Genetic factors
Altered genetic material passed from parent to offspring is
called genetic factors, which is classified into three
groups.
Genetic disorders
⮚Chromosome disorders: numerical and structural
abnormalities of chromosome.
⮚Single-gene disorders: the defect is caused by a single
defective or mutant gene.
⮚ Multifactorial inheritance: polygenetic disorder. 33

34. Common Examples of Genetic Disorders
Disorder Classification Genetics
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Single-gene disorder
Huntington
disease
Cystic fibrosis Single-gene disorder
Single-gene disorder
Autosomal
dominant
Autosomal
dominant
X-lined dominant
Hypophosphatemia
(vitamin D-
resistant rickets)
Hemophilia
Down syndrome
Turner syndrome
Single-gene disorder
Chromosome disorder
Chromosome disorder
X-lined dominant
risomy 21
45, X

35. Down syndrome
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47, +21

36. Inherited disease: disease caused by altered
genetic material, either single gene mutation or
chromosome aberrations. e.g. color blindness,
Albinism, Down syndrome.
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37. Disorder of multifactorial inheritance result from a
combination of the multiple gene variations with
environmental factors. Therefore the disease on phenotype are
not hereditary, but these diseases do have a genetic background
(genetic susceptibility), such as congenital heart disease, cleft
lip, coronary artery disease and hypertension.
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38. Genetic predisposition (genetic susceptibility):
a state of body favorable to or showing a
tendency to certain diseases because of
polygenetic abnormalities.
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39. 2) Congenital factors
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Environment factors that occurred during
embryonic or fetal development are called congenital
factors, including the physiologic status of the mother
(maternal disease) and teratogenic agents (infections or
drugs taken during pregnancy), which acts on the embryo
or fetus, causing abnormalities in form or function.
Diseases caused by congenital factors
called congenital disease. e.g. congenital syphilis.

40. 3) Immunological factors
Although the immune response is a normal protective
mechanism, it may cause disease while the response is
deficient (immunodeficiency disease), inappropriately
strong (allergy or hypersensitivity----penicillin), or
misdirected (autoimmune disease----).
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41. 4) Psychological factors
Anxiety, strong or persistant psychological stimulation
or stress may lead to mental illness and may be related
to some disease such as:
hypertension, peptic ulcer (duodenal ulcer), and
coronary heart disease.
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42. - Conditional Factors
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1) Body’s condition: age, sex, race; physical
training, mental condition, fatigue, smoking,
lifestyle.
2) Nature condition: weather condition and
geographical environment influence some
epidemical diseases.
3) Social condition: labor and hygiene
conditions----occupational diseases, social
life events----person’s mood and life pattern.

43. Reversal role of cause and result
The cause of the disease lead to a result, which can
be another cause of the disease in the evolution
process.
(Cause)
Chronic hypoxia polycythemia
(Result)
blood viscosity ￪
(Result)
erythrocyte￪
(Cause)
thrombus
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44. Returned blood
volume ↓ Blood pressure↓↓
Microcirculation
congestion Sympathetic nerve excite
Capillary open Vasoconstriction
Hypoxia in tissure
vicious cycle
Contractility ↑
Maintain BP
beneficial cycle
Heart rate ↑
(Cause)
Mechanical trauma
(Result)
Hemorrhage
(Cause)
Cardiac output↓↓
(Result)
Recovery
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45. Outcome of Diseases
Recovery
Death
Complete recovery
Incomplete recovery
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46. 1 Complete recovery
⮚The alterations of the function, metabolism
and structure of the body, which appeared in
disease, are perfectly restored.
⮚The signs and symptoms of the disease are
disappear entirely.
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47. 2. Incomplete recovery
⮚The main symptoms are absent.
⮚Some pathological changes are still present in the body.
⮚It is brought about by the compensatory response to
maintain a relatively normal life activity.
--e.g. Heart disease patients.
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48. Death
Definition:
Irreversible cessation of the function of the body as a
whole.
Contemporary concept of death is brain death.
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49. Definition of brain death
Prolonged irreversible cessation of all brain functions,
including the brain stem.
Diagnosis of Death
The bases for demonstrating brain death are the
absence of brain stem reflexes, absence of cortical activity
and demonstration of irreversibility of the state.
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50. Criteria indicating brain death
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◆ Irreversible coma and cerebral
unresponsiveness: complete lack of cerebral
response to any form of external excitation.
◆ Absence of all brain stem reflexes: It
includes the absences of pupilary reflex,
corneal reflex, cough reflex and swallowing
reflex.
◆ Cessation of spontaneous respiration

52. ◆Absence of any electrical activity of brain
indicated by EEG (electroencephalogram)
for at least 6 hours.
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◆ Cessation of cerebral circulation

53. Irreversible cessation of all brain functions, including the
brain stem is called brain death.
The bases for determine it are absence of cortical activity,
absence of brain stem reflexes, and demonstration of
irreversibility of the state.
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54. Senescence (Aging)
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Aging is a natural, lifelong process. There
is a general decline in the structure and
function of the body with advancing age,
resulting in a decreased reserve capacity of
the various organ systems. This results in a
reduction of homeostatic capabilities, making
the older adult more vulnerable to stressors
such as illness, surgery, medical administration,
and environmental changes.

55. ⯎Experimental study Reproduce disease model i n
animals, isolated organs and cells, and observe or
perform something.
⯎Clinical study Observe directly the patient’s symptom,
laboratory testing, the rules of evolution; study the
treatment and prognosis.
⯎Epidemiological study Study the cause or conditional
factors, risk factors, rules of development of some
infective diseases
. Research Methods for Pathophysiology
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56. Thank you