Pathology is the study and diagnosis of disease. It has four main components: the cause or etiology, the mechanism of development/pathogenesis, structural alterations to cells (morphological changes), and the consequences of these changes (clinical manifestations). Pathology has evolved from autopsy and organ-based examination to cellular pathology and now utilizes various techniques including molecular pathology, genetics, immunology, and quantitative analysis. Key techniques used in pathology include autopsy, biopsy, cytology, animal experimentation, tissue/cell culture, histology, immunohistochemistry, electron microscopy, flow cytometry, image analysis, and molecular biology techniques like PCR and DNA sequencing.

1. Introduction toIntroduction to
PathologyPathology
OPTOM FASLU MUHAMMEDOPTOM FASLU MUHAMMED

2. Pathology –” Study and diagnosis of disease”
4 components of pathology
1. Cause /etiology
2. Mechanism of develop- Pathogenesis
3. Structural alteration of the cell- Morphologic
changes
4. Consequences of these changes – Clinical
Manifestations

4. 一、一、 History of PathologyHistory of Pathology
Autopsy → Organ pathology (1761)
Cellular pathology (1854)
Ultrastructural pathology with the application
of EM (20 century 60s)
Immunopathology, Molecular pathology,
Genetic pathology, Quantitative pathology

5. 2. Classification:2. Classification:
(1) Human pathology
(2) Experimental pathology
3. Position:
It’s a bridging discipline involving both
basic science and clinical practice
Autopsy
Biopsy
Cytology

6. 4. Text of Pathology:4. Text of Pathology:
(1) General pathology:
concerned with the basic reaction of
cells and tissues to abnormal stimuli
that underlie all diseases.
(2) Systemic pathology :
dedcribe the specific responses of specialized
organs and tissues to defined stimuli.

7. 三、三、 Techniques of PathologyTechniques of Pathology
1. Human pathology
(1) Autopsy
(2) Biopsy: surgical or diagnostic pathology
(3) Cytology: smear, fine needle aspiration
2. Experimental pathology
(1) Animal experiment: animal model
(2) Tissue and cell culture

9. 四、四、 Observation and NewObservation and New
Technique of MorphologyTechnique of Morphology
（一） Gross appearance:
size, shape
weight
color
consistency
surface
edge, section

10. （二）（二） Histologic and cytologicHistologic and cytologic
observation:observation:
most common and basic formalin fixed
→ HE (hematoxylin and eosin) stained
Hemangioma of ventrical wall

11. （三）（三） Histochemistry and cytochemistryHistochemistry and cytochemistry
PAS→BM

12. （四）（四） ImmunohistochemistryImmunohistochemistry
1. Ag-Ab specific reaction
2. Applications
(1) Location analysis
cytokeratin→cell membrane
(2) Clinical diagnosis and distinguishing
diagnosis of tumor histogenesis

13. Leiomyosarcoma Actin (+)

14. （五）（五） UltrastructuralUltrastructural
observationobservationTEM (transmitting electron microscope)
Filtering membrane

15. SEM (scanning electron microscope)
Podocyte

16. （六）（六） Flow cytometry (FCM)Flow cytometry (FCM)
1. One kind of cells→quantitative
2. DNA ploidy analysis
3. Protein nucleus acid→quantitative
analysis
4. Selection of collection of cells

17. （七） Image analysis (IA)
Nuclei: diameter; circumference; area;
volume; morphology
（八） Laser scanning confocal
microscope (LSCM)
a living cell→observation in situ or
development or quantitative

18. （九）（九） Molecular biology techniqueMolecular biology technique
1. Polymerase chain reaction (PCR)
2. DNA sequencing
3. Biochip technique
(1) Gene chip (DNA chip)
(2) Protein chip (protein microarray)
(3) Tissue chip (tissue microarray)

19. PolymerasePolymerase
chainchain
reactionreaction
(PCR)(PCR)