Genpathnotes

GENERAL PATHOLOGY

INTRODUCTION

Pathology is the study of disease (pathos means suffering; logos means study). It studies the essential nature of disease as well as the structural and functional changes in cells, tissues and organs that are caused by disease.

There are four aspects of a disease that form the core of pathology:

1. ETIOLOGY, which is the cause of the disease;

2. PATHOGENESIS, which refers to the mechanisms that brought about the disease process;

3. MORPHOLOGIC CHANGES, which refers to structural alterations brought about by the disease.

4. CLINICAL SIGNIFICANCE/MANIFESTATIONS, which refers to SIGNS and SYMPTOMS, DISEASE COURSE and PROGNOSIS, all of which are the functional consequences of the morphologic changes.

ETIOLOGY

There are two major classes of etiologic factors:

1. Intrinsic or Genetic

2. Acquired (e.g. infectious, nutritional, chemical, physical)

PATHOGENESIS

This refers to the sequence of events that happen in cells when they respond to an etiologic agent, from the initial stimulus to the ultimate expression of the disease.

CLINICAL SIGNIFICANCE

Manifestations of a disease can either be signs or symptoms.

Signs are objective findings. Examples: Fever, Hypotension, Rash.

Symptoms are subjective findings. Examples: Dizziness, Headache, Fatigue.

The term “Pathognomonic” refers to a feature (Morphology or clinical manifestation) that is specific to certain disease. Examples:

Morphology: Negri Body for Rabies and Hypersegmentation for Megaloblastic Anemias.

Manifestation: Koplik’s spot for measles and Herman’s rash for Dengue Fever.

The course of illness of a disease refers to the PATTERN from time of manifestation (first sign or symptom) until resolution/death. The details included in the course of an illness include:

* Onset: Acute, Subacute or Chronic

* Duration

* Prognosis: prediction of the outcome of the disease

Traditionally, Pathology is divided into General...