This document provides an introduction to pathophysiology. It defines key terms like pathology, clinical pathology, hematology, immunology, disease, disorder, inflammation, and infection. It discusses the need to study pathophysiology and concepts of homeostasis and feedback mechanisms. Pathology is the study of the cause, origin, and nature of disease by analyzing tissues, blood, and fluids. Clinical pathology uses tests in biochemistry, microbiology, hematology and immunology for disease diagnosis. Homeostasis refers to maintaining internal equilibrium despite external changes through feedback loops.

1. INTRODUCTION TOPATHOPHYSIOLOGY
-ARCHANA. M
M.PHARM (ANALYSIS)
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2. OBJECTIVES
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In this sessionwe will be focuson:
•Define Pathology and pathophysiology.
•Clinical pathology, clinical bio chemistry, clinical
microbiology, Haematology, clinical immunology.
•Define disease, disorder, inflammation, infection.
•Need of pathophysiology study
•Concept of Homeostasis and five mechanisms.

3. PATHOLOGY
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• The word pathology is from Greek ,pathos, means
"feeling, or suffering"; and logia, means "the study
of".
• Pathology is abranch of medical science
primarily concerning the cause,origin and
nature ofdisease.
• Body tissue, blood and other bodily fluids are
analyzed to assist medical practitioners inidentifying
the causeand severity of disease,and to monitor
treatment.

4. CLINICAL
PATHOLOGY
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• Clinical pathology is amedical specialty that is
concerned with the diagnosis of disease basedon
the laboratory analysis of bodily fluids suchasblood
and urine, aswell astissues, using the tools of
biochemistry, clinical microbiology, hematology,
immunology e.g.PCR (polymerase chainreaction).

5. CLINICAL
BIOCHEMISTRY
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• Clinical biochemistry (chemical pathology, clinical
chemistry) is the area of chemistry that is generally
concerned with analysis of bodily fluids
for diagnosticpurposes.
Blood, urine or bodily fluid for various tests e.g. RFT
s
(Renalfunctionaltests), LFT
s( liver functional tests) RBS,(random
bloodsugartest)FBS,(fastingbloodsugartest)Serum Albumin,
SerumElectrolytes etc.
•

6. CLINICAL
MICROBIOLOGY
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• Clinical Microbiology deals with isolationand
identification of infectious agents suchas
bacteria, viruses, fungi and parasites that
causedisease.
• Specimenssuchasurines, feacesand swabsto
identify pathogens to select the appropriate
treatment.
e.g. Blood C/S,Urine C/S,Sputum C/S

7. HEMATOLOGY
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• Isthe study of diseaseswhich affect blood.
Investigations that take place theHematology
laboratory include:
• Routine hematological testing
Specimensof whole blood are analyzed by a
specialized instrument called aCoulter Counter
which measures the number of thevarious blood
cells such asred cells, white cells andplatelets
• E.g.Complete blood count, ESR,Blood smearetc

8. CLINICAL
IMMUNOLOGY
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• Clinical Immunology is concerned with the
diagnosis and management of diseasesarising
from abnormal immuneresponses.
• In broad terms, these abnormalities maybe
the result of either under activity
(immunodeficiency) or over activity
(autoimmunity and allergy) of the immune
system.

9. DISEASE
• Theterm disease literally means “without ease”
(uneasiness), when something is wrong with
bodily function.
• Theterm disease broadly refers to any condition
that impairs the normal functioning ofthe body.
• Diseasesare associated with dysfunctioning of
body's normal homeostatic processes.
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10. DISORDER
• Anatomical disturbances or abnormalities are known as
disorders.
• Eg: Fracture, Alzheimer’s
• Disorder categories- Physical disorder
- Mental disorder
- Genetical disorder
 - Behavioral disorder
 - Functional disorder

11. PATHOPHYSIOLOGY
1. Basically, pathophysiology is the
disordered physiological processes
associated with injury or disease(the
immune system). Thisarea studies how
the body reacts to injury or fights off
disease.
2. The functional changesassociated with or
resulting from diseaseor injury.
e.g. inflammation in response to aninjury
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12. INFECTION
• Infection is growth of a parasitic organism with in the body.
• The invasion and multiplication of microorganisms such as
bacteria, viruses, and parasites that are not normally present
within the body.
• An infection may cause no symptoms and be subclinical, or it
may cause symptoms and be clinically apparent.

13. INFLAMMATION
• Inflammation is a protective mechanism of the body to
remove the injurious stimuli.
• Inflammation is a process by which your body's white blood cells
and the things they make protect you from infection from outside
invaders, such as bacteria and viruses.

14. PATHOGENESIS
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Theword Pathogenesiscomes
from the Greek pathos
("disease") and genesis
("creation").
Thepathogenesisof adiseaseis the
biological mechanism that leads to
the diseasedstate.
Theterm can also describe the origin
and development of the disease, and
whether it is acute, chronic, or
recurrent.

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Basicconceptof diseaseanditsdevelopment
• Infection by pathogen is influencedby
several factors:
• Mechanismof action:pathogens directly
damage cells, interfere with cellular
metabolism, and render the celldysfunctional.
Becauseof the accumulation of pathogenic
substances and toxin production.

16. C
ONTI…
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1. Infectivity: ability of the pathogen to invade
and multiply in the host.
2. Pathogenicity:the ability of an agent to
produce diseasedepend on its speed of
production, extent of tissue damage,and
production of toxin.
3. Virulence:the potency of apathogen
measured in terms of the number of
microorganisms of toxin required to kill a
host.

17. C
ONT…
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5. Immunogenicity: the ability of pathogens to
induce an immune response.
6. Toxigenicity: afactor important in
determining a pathogen's virulence, such
hemolysin, leucocidin and other exotoxins,
and endotoxin.Hemolysin destroy
erythrocytes, and leucocidin destroys
leukocytes, both are product of streptococci
and staphylococci.

18. CONT…
 7.Portalofentry:the route bywhich a pathogenic
organisminfect the host :direct contact, inhalation,
ingestion, or bite of an animal orinsect.
Spreadof infection isfacilitated bythe ability of pathogens
to spreadthrough lymph and blood andinto tissueand
organs,wherethey multiply andcausedisease.
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19. NATURAL HISTORYOF
DISEASE
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• Thenatural historyof diseaseis the course
adiseasetakes place in an individual from
its pathological onset to its eventual
resolution through complete recovery,
disability or death in the absenceof
intervention.
• It hasfour stages 1) stage of susceptibility 2)
stage of subclinical disease3) stage of clinical
disease2) stage of recovery, disability or
death

20. NATURAL HISTORYOF
DISEASE
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21. ETIOLOGY
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• Etiology,is the study of causation or
origination. Theword is derived fromthe
Greek, aitiologia, "giving areasonfor“
• Used in medical and philosophical theories,
where it is used to refer to the study of why
things occur, or even the reasons behind the
way that thingsact.

22. CLINICAL
MANIFESTATION
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• Clinical manifestations are the observable
symptoms by which adiseasemay be
diagnosed. It is how adisorder'manifests'
itself to anobserver.
• E.g.jaundice, cyanosis,clubbing, redness

23. OUTCOME
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• Theconsequence of diseaseor end of the diseaseis
known asoutcome which may any of the following
form
– Complete recovery
– Recovery with disability
– Death

24. NEED OF PATHOPHYSIOLOGY
STUDY
• It helps health care professionals to find
answers causes of the disease, onset,
progression, symptoms and signs, recovery.
• To understand mechanism of disease for
effective treatment.
• It is a required area for all health care
professionals in all school programs.

25. HOMEOSTASIS
• The maintenance of internal environment of
the body in equilibrium despite the external
changes of the body.
• It was proposed by Claude Bernard in 19th
century.
• Every organ plays a major role in maintain
the internal environment.

26.  Homeostatic regulatory mechanism :
• It consists of 5 parts
• 1. Receptors
• 2. Sensory neurons
• 3.Integrated center
• 4.Motor receptor
• 5.Effector

27. ADAPTATION
• Adaptation refers to process by which system seeks to restore or
maintain homeostasis.
• Adaptation may be physiological, psychological, behavioral.
• Adaptive mechanism may be represented by positive and
negative feedback mechanisms.

28. NEGATIVE FEEDBACK LOOPS
• When the response of effectors opposes
the original stimulus it is called negative
feedback mechanism.
• Stimulus( stress)
• Disrupts Homeostasis
• Increase in body temperature
• Thermo receptors in brain and skin gets
activates and sends message to control
center via nerve impulse.
• Control center analyses and sends input to
skin which is effector.
• Effector increases sweat production from
sweat glands. Finally decreases the
temperature to control condition.

29. POSITIVE FEEDBACK MECHANISM
• Effectors instead of negating speeds up the
process.
• Labor contractions pushes the baby to birth
canal.
• Effect the control condition and increases
distention of the cervix.
• Stretch receptors of cervix are activated and
impulse is sent via nerves.
• Control canter activates pituitary gland to secrete
oxytocin in blood.
• Oxytocin is carried to uterus and stimulates
contractions, pushes the baby through birth
canal.
• Birth of baby decreases the distention of cervix
and interrupts the positive feedback mechanism.