Pathology is the study of diseases and their causes, mechanisms, and effects. It involves examining tissues and cells using various laboratory techniques to establish diagnoses and understand disease processes. Key aspects of pathology include histological examination of biopsies and autopsies using staining methods, as well as newer techniques like immunohistochemistry and molecular analysis, which provide information critical to clinical diagnosis and treatment.

1. Pathology

2. Pathology
 surgical pathology report-diagnosis based on
microscopic and gross examination of surgicals
 autopsy report-diagnosis of disease and cause of
death, describes morphologic changes, studies
pathogenetic consequencies

3. There are 3 types of joints present in the thoracic spine:
Between vertebral bodies – adjacent vertebral bodies are joined by intervertebral
discs, made of fibrocartilage. This is a type of cartilaginous joint, known as a
symphysis.
Between vertebral arches ie facet joints – formed by the articulation of superior
and inferior articular processes from adjacent vertebrae. It is a synovial type joint. In
the thoracic spine facet joints angled at:
•60° to the transverse plane
•20° to the frontal plane, with the superior facets facing posterior and a little up and
laterally and the inferior facets facing anteriorly, down, and medially.
•motion: lateral flexion and rotation; no flexion/extension
Costovertebral joints, unique to the thoracic spine - consists of the head of the rib
articulating with:
•Superior costal facet of the corresponding vertebra
•Inferior costal facet of the superior vertebra
•Intervertebral disc separating the two vertebrae
Within this joint, the intra-articular ligament of head of rib attaches the rib head to the
intervertebral disc. Only slight gliding movements can occur at these joints, due to
the close articulation of their components

5. Pathology
 The study of pathology is divided into:
 general pathology- concerns with basic
reactions of cells and tissues to abnormal
stimuli that are common for a group of
diseases or that underlie all diseases or
groups of diseases
 special pathology- examines specific
responses of specialized tissues and
organs to pathologic stimuli
 oncologic pathology- deals with
neoplastic processes (tumours)

6. DEFINITIONS OF BASIC ASPECTS OF
DISEASE PROCESS
 Pathology
 medical discipline which provides the link
between basic biological sciences and the
practice of medicine. Pathology is a
logical, scientific basis of medicine
 is the study of changes which occur in
cells and tissues as a result of either
genetic inborn or environmental damage,
is a study of diseases
 the study provides understanding of the
processes (their causes, clinical effects
etc)..

7. Pathology
 -as a science-
 focuses on mechanisms by which cells and tissues are
injured, on structural and functional consequences of
injurious stimuli on cells, tissues, and organs, finally on
the entire organism
 - it is a morphologic discipline- describes pathological
morphologic findings in tissues and cells

8. Pathology
 -as a medical discipline-
 deals with a performance and an
interpretation of laboratory procedures,
leading to diagnosis
 -these include many diagnostic and
investigative techniques and concern with
interpretation of laboratory procedures-
examples: histologic examination of
surgical biopsies, cytological examination
of smears and FNA (fine needle aspirates),
bone marrow smears, etc.

9. Pathology
 Two main fields of pathology as medical
discipline:
 (1) surgical pathology -deals with
interpretation of histological examination
of tissues and organs removed in surgery
from living patients
 (2) autopsy pathology -is concerned with
examination of gross, macroscopic and
histological changes in diseases studied in
dead persons

10. Pathology
 Forensic pathology - is performed and practised
separately from pathology- in faculty hospitals, both
disciplines are closely related in small and district
hospitals
 - main task is to determine whether death was due to
natural or unnatural causes, such as caused by accident,
other person, murders etc.
 -in large medical centers and faculty hospitals-
pathologists usually subspecialize in a distinctive
discipline, i.e. cytology, hematopathology, surgical
pathology, gynecological pathology

11. WHAT IS PATHOLOGY
 Pathology is a study of diseases.
 The study provides understanding of the processes
(their causes, clinical effects etc).

12. Pathology
 -in broader terms, pathology means also study of the
diseases, their causes, prevention and classification

13. Disease
 Disease- is defined as a physiological or psychological
dysfunction.
 -it can be caused by obvious structural abnormalities,
or may be less well defined-without obvious
morphological damage, such as in anorhexia nervosa-
mental anorhexia

14. Diseases
 All diseases have certain aspects which can form
the basis for classification- these include
 -pathology focuses on the following different
aspects of disease
 -epidemiology (occurrence and incidence of d.)
 -etiology (causes of disease)
 -pathogenesis (mechanisms of disease)
 -morphology of the tissue changes
 - clinical significance and consequencies

15. Disease
 1.epidemiology-provides a wider context for the study,
classification, and diagnosis of diseases
 -epidemiological data are important
 -for providing informations about causes of
diseases.
 -for identifying risk factors
 -for providing adequate health care, and planning
disease prevention, epidemiology records data
about
 .incidence-number of new cases occurring in a defined
population over a defined time period

16. Disease
 prevalence-number of cases found in a defined
population at a stated time
 morbidity-number of diseased persons in a given
locality, nation etc. and mortality-number of deaths to
the population

17. Disease
 2.etiology studies causes of disease
 diseases result from the interaction between individuals and their
environment
 -the other diseases result from an environmental factors acting in
conjunction with a genetic predisposition
 -in some instances the underlying cause of a disease is obscure-
idiopathic, spontaneous, essential

18. classification of diseases
 classification of diseases - based on the etiologic
factors, diseases can be classified to two categories
 -congenital- present at birth, even though they are
sometimes recognized later
 -acquired- occur only later after births (infectious,
nutritional, chemical, physical, radiation injury etc.)

19. Disease
 3.pathogenesis- etiopathogenesis
 -refers to the sequence of events in the response of
the cells, tissues, organs to the injurious stimuli that
may lead to a disease
 -describes mechanisms of development of disease
 -study of pathogenesis remains a main domain of the
scientific pathology

20. Disease
 4.morphological changes
 -structural alterations induced in cells and tissues
 -refers to the structural alterations of cells or tissues
that are either characteristic or diagnostic of a disease
 -there are gross/ macroscopic findings and histological
microscopic findings

21. Disease
 5.clinical significance
 -functional consequencies of morphologic changes, as observed
clinically
 -morphologic structural changes of cells, tissues and organs are related
to functional disorders, morphologically altered tissues do not provide
normal functions, and these consequent pathologic functions are
studied in details in many clinical disciplines- pathology provides basic
information with respect to clinical outcome, prognosis, etc.

22. Disease
 -symptoms- features of illness that are noticed by
patients
 -signs- clinical manifestation of the disease which are
recognized by clinicians

23. Type Basis Examples
Congenital Genetic Hemophilia A
(absence of clotting factor
VIII)
Non-genetic Intrauterine rubeolla infection
(measles) leads to
deafness/blindness in the
fetus
Acquired Inflammatory Dermatitis (eczema,
inflammation of the skin)
Vascular Atherosclerosis
Growth and proliferation
disorders
Tumors
Metobolic Gout (deposition of uric acid
crystals in joints and soft
tissues
Degenerative Alzheimer disease-demensia
Infective / Drug induced tbc / Renal failure

24. THE ROLE OF PATHOLOGY IN DIAGNOSTIC
PROCESS: FROM CLINICAL REASONING TO
MOLECULAR BIOLOGY.
 patients present with symptoms and
clinical examination reveals signs which
suggest a diagnosis
 -examination of various specimens in
pathology laboratories helps to establish
and confirm diagnosis, and monitor the
treatment
 Diagnosis is the act of identifying a
disease in an individual patient and is
based on clinical history, physical
examination and pathology investigation

25. Diagnosis
 Diagnosis involves skills and laboratory tests
 Special pathology techniques are used
 Special stains, immunohistochemistry and molecular
biology techniques are routinely used

26. The role of pathologist:
 Looking at samples of tissues (biopsies)
 Using the range of special laboratory
techniques
 Histology
 Autopsy
 Special stains
 Immunohistochemistry
 Electron microscopy
 Molecular biology techniques

27. METHODS IN PATHOLOGY
Diagnostic and investigative techniques used in pathology
 routine histological techniques –fundamental for
histopathologic diagnosis – these techniques use
different coloration of cells and tissues and cell
components using different staining methods

28. most commonly used staining
methods-
 hematoxylin and eosin stain- combination of
haematoxylin and eosin remains the gold standard,
method used for majority of histopathologic
diagnoses- method is now over 100 years old
 haematoxylin- is natural product of blue colour, is
used mostly for staining the nuclei- shows general
morphology of a tissue
 -eosin- the most frequently used partner stain
because it is easy to stain, and its red colour
contrasts well with blue colour of haematoxylin-
eosin stains cytoplasm

29.  special stains- HE is important as a general staining
procedure but it is sometimes necessary to use other
staining procedures in order to demonstrate more
selectively the particular tissue components
 -connective tissue components, such as collagens,
muscle fibers can be demonstrated by Van Gieson
stain or trichrome stains
 reticulin (type III collagen) can be shown by silver
impregnation technique

30.  -basement membrane components (such as type IV
collagen, laminin) are well demonstrated with the
periodic acid-Schiff (PAS) method, silver
according to Gomory, etc.

31. Recommended Reading
Material
 1. Cotran RS, Kumar V and Collins T. Robbin: Pathologic basis of
Diseases, WB Saunders, Philadelphia.
 2. Klatt EC and KumarV: Robbins Review of Pathology. W. B.
Saunders, Missouri.
 3. Harsh Mohan: Textbook of Pathology