INTRODUCTION TO PATHOLOGY
DEFINITION
PATHOLOGY is the study of disease.
• Pathos = disease, suffering
• Logos = study
Pathology serves as a bridge between the preclinical sciences (anatomy, physiology etc.) and the courses in clinical medicines.
DISEASE
It is taken from Dis mean without and Ease means easiness.
It is the state in which an individual exhibit an anatomical, physiological or biochemical deviation from the normal.
Disease may be defines as an abnormal alteration of structure or function in any part of the body.
DIVISIONS OF PATHOLOGY
General pathology:
The basic response of cells and tissues to abnormal stimuli. It describes the basic principles of development of disease. E.g. inflammation, cancer.
Systemic pathology:
It is the specific response of tissue and organs to one or more defininte stimuli. It deals with the disease
of special organ or system. E.g. Appendicitis, lung cancer etc.
Classification of Diseases
• Inflammatory diseases
o Hepatitis
o Appendicitis
o UTI and etc.
• Degenerative Diseases
o Ortharhtritis etc.
• Neoplastic Disease
o Lung cancer, Breast cancer
• Traumatic Disease
o Fracture etc.
ASPECTS OF DISEASE PROCESS
1. Aetiology
2. Pathogenesis
3. Molecular & Morphological changes
4. Clinical significance/ manifestations
Aetiology( Cause )
Study of the cause of disease
Knowledge of etiology remains the backbone of
• Disease diagnosis
• Understanding the nature of disease
• Treatment of disease
• An etiologic agent
Is the factor (bacterium, virus etc) responsible for lesions or a disease state
• Predisposing causes of deasee
Factor which make an individual more susceptible to a disease (damp, weather, poor ventilation, cigarette, smoking etc.)
• Exciting causes of Disease
Factors which are directly responsible for a disease are excited by a particular factor
Acquired or Environmental
Physical, Chemical, Nutrition, Infections, Immunological, Psychological
Genetic Factors
Abnormalities in chromosomes and genes
Multifunctional
Acquired and Genetic factors combined as in diabetes, hypertension and cancer.
Pathogenesis
The sequence events during the response of the cells or tissues to the etiologic agent from the initial stimuls to the ultimate expressionW of the disase, “from the time it is initated to its final conculusion in
recovery or death”
Morphologic Changes: Structural Changes
Structural changes in disease
• Tumor in caner
• Ulcer in infection
• Atrophy in dementia
Gross and Microscopic
Clinical Significance
Symptoms and Signs
➢ Clinical symptoms are the patient complaints usually by its own words
➢ Clinical signs are seen only in living individual
➢ Functional evidence of disease which be determine objectively or by the observer (fever, tenderness, increased respiratory rate etc.)
Necropsy: Gross examination of the animal cadaer by systematic dissection in order to evaluate any abnormal changes (lesions) that may be present
Autopsy: Synonymous to necropsy in human medicine
Biopsy: Removal and examination of tissue obtained from the living body
Prognosis
Expected outcome of the disease, it is the clinician estimate of the severity and possible result of a disease.
