INTRODUCTION TO PATHOLOGY

Introduction to pathology –

Greek word

Pathos – suffering or Disease.

Logos – study.

Study of Disease.

Definition

Scientific study of structure and function of the body in disease.

It deals with causes, effects, mechanisms and nature of disease.

Terminologies –

Health – It is a condition when an individual is in complete accord with the surroundings. 

Disease – Dis-ease.

Loss of ease to the body.

Patient – Is the person affected by disease.

Symptoms (complaints of the patient) and signs (physical findings elicited by the clinician)

Illness – It is the reaction of an individual to disease in terms of symptoms & signs.

Syndrome – Combination of symptoms of different diseases.

(Two different diseases running together).

Lesions – Characteristic changes in tissue and cells produced by disease. 

These changes, also called as pathological changes or morphology, are studied by naked eyes (gross or macroscopic changes or morphology) or by microscopy (microscopic changes or histopathology)

Etiology – causal factors responsible for the disease process (why of the disease).

Pathogenesis – process or mechanism by which the lesions are produced. 

Evolution of pathology

Antiquity to 1500 AD

Religious beliefs (Speculative philosophy) to rational approach.

Evil eye of spirits or curse by the wrath of malevolent gods.

Greek god – Aesculapius – God of healing

Indian doddess – Mata Sheetla Devi Goddess of healing for cure of small pox.

Rational approach started in Greek philosophers –

Socretes, Plato, Aristotle.

Hippocrates (460 – 377) BC Greek clinical genius of all times – Father of Medicine

- started study of patients symptoms

- described methods of diagnosis

- introduced ethical concepts(Hippocratic oath)

In India – about 200 A.D.

Charak samhita – Finest document on medicine

Sushruta samhita – Document on surgical sciences

Cornelius celsus (53 BC to 7AD) in Rome first described cardinal signs of inflammation.

Era of Gross Pathology (Morbid Anatomy) 1500 -1850 A.D.

Began from Italy

Leonard-da-Vinci (1452 – 1519)

Artist, Engineer & scientist

Gabriel Fallopius (1523 – 1562)

Discovered fallopian tube.

Antonie van Leeuwenhoek (1632 – 1723)

Draper by profession, made first microscope

Started histological staining by using saffron.

Giovanni B. Morgagni (1682 – 1771)

Started the study of morbid anatomy

(pathologic anatomy)

He did 700 post mortems and published clinical findings and started clinico-pathological correlation to establish a coherant sequence of cause, lesions, symptoms and outcome of disease.

Father of modern anatomical pathology

In England –

Sir Percival Pott (1714 – 1788) Famous surgeon described occupational cancer in Chimney sweepers.

His student,

John Hunter (1723 – 1793) greatest surgeon anatomist and his brother,

William Hunter – anatomist, obstetrician, started first

museum with 13,000 specimens. (Hunterian Museum in England).

His student,

Edward Jenner (1749 – 1823)

Vaccine on small pox.

In France –

RHt Laennec (1781 – 1826) – Physician described several lung diseases, liver diseases and invented stethoscope.

In Germany –

Carl F. Von Rokitansky (1804 – 1878) Pathologist, performed 30,000 autopsies.

Richard Bright (1789 – 1858) – described non suppurative nephritis (Glomerulonephritis) (Bright’s disease)

Thomas Addison (1793 – 1860) – described Addison’s disease.

Era of Technology Development and Cellular

Pathology (1850 – 1950 A.D.)

Correlation of clinical manifestations of disease with pathological findings at autopsy due to technical improvement in microscope and development of new stains, pathology started developing as a diagnostic discipline in later half of the 19th century

Louis Pasteur (1822 – 1895) – Discovered microorganisms.

G.H.A. Hansen (1841 – 1912) – Identified Hansen’s bacillus as causative organism for Leprosy in 1873.

Edward Jenner – Made concept of immune tolerance and allergy. He also prepared first vaccine against Small pox.

Paul Ehrlich ( 1854 – 1915) – German physician got Nobel prize for work in immunology. He started staining techniques of cells & prepared Ehrlich’s aldehyde reagent for urobilinogen.

Christian Gram (1853 – 1988) – Danish physician and D.L. Romanowsky (1881 – 1921) – Russian physician found out various stains useful in pathology.

Robert Koch (1843 – 1910) – German bacteriologist described Koch’s postulates and Koch’s phenomenon. He discovered Tubercle bacilli in 1882 and Cholera Vibrio organism in 1883) May-Grunwald in 1902 and Giemsa in 1914 contributed in preparation of stains.