Outline of Lecture:
Definition of pathology
It is the “Scientific study of disease” .
“scientific study of the molecular, cellular, tissue, or organ system response to injurious agents.”
What is the Disease?
It is the “State in which an individual exhibits an anatomical, physiological, or biochemical deviation from the normal”
Classification of Diseases:
Developmental – genetic, congenital.
*Inflammatory – Trauma, infections, immune, etc.
*Neoplastic – tumors cancers
*Degenerative – ageing.
*Iatrogenic: Drug induced.
Basic Language of Pathology
Common changes in all tissues. e.g.. Inflammation, cancer, ageing, edema, hemorrhage ….etc.
Discussing the pathologic mechanisms in relation to various organ systems e.g. CVS, CNS, GIT…..etc.
What should we Know About A Disease
Epidemiology – Where & When.
Etiology – What is the cause?
Pathogenesis – Evolution of dis.
Morphology – Structural Changes
Pathology focuses on 4 aspects of disease:
Knowledge of etiology remains the backbone of:
Understanding the nature of diseases
Treatment of diseases.
“Study of the cause of a disease”
An etiologic agent :
is the factor (bacterium, virus, etc.) responsible for lesions or a disease state.
Predisposing Causes of Disease:
Factors which make an individual more susceptible to a disease (damp weather, poor ventilation, etc.)
Exciting Causes of Disease:
Factors which are directly responsible for a disease (hypoxia, chemical agents…. etc.).
What is the cause?
The sequence events in the response of the cells or tissues to the etiologic agent, from the initial stimulus to the ultimate expression of the disease,”from the time it is initiated to its final conclusion in recovery or death”
Clinical Symptoms & Signs
Clinical signs are seen only in the living individual.
“Functional evidence of disease which can be determined objectively or by the observer” (fever, tenderness, increased respiratory rate, etc.)”
Expected outcome of the disease, It is the clinician’s estimate of the severity and possible result of a disease.
Study of what is abnormal or wrong or disease…!
“Scientific Study of Disease”
Normal à Abnormal Treat
“Is the foundation of medical science and practice. Without pathology, the practice of medicine would be reduced to myths and folklore”
What is “Diagnosis”?
The formal name(s) used to describe a patient’s disease
The process of identifying a disease based on the patient’s symptoms, the doctor’s findings, and the results of investigations and laboratory tests
What do you need to make a diagnosis?
A system of classification that supplies the necessary names, definitions, and criteria
The means to ascertain the defining characteristics of a disease in the individual patient
Past and Present….!
In the past, .. people mistook magic for medicine…!
Now people mistake medicine for magic….!
Subdivisions of clinical Pathology:
Common changes in all tissues.
E.g.. Inflammation, cancer, ageing.
Specific changes in organs.
E.g.. Goiter, pneumonia, breast cancer.
Study of Disease: (Pathology)
Etiology – Causes
Pathogenesis – Evolution
Morphology – Structural Changes
Clinical Significance – Functional Changes
Techniques in Pathology:
Cell Cultures, Medical Microbiology
Right neck mass
Diffuse pattern – no follicles.
Large cells with moderate cytoplasm
Plenty of mitotic figures, Nuclei are vesicular prominent nucleoli
Features suggest T-cell NHL – malignant lymphoma.
Needs further marker studies for typing & management.
Carcinogenesis. DNA Damage, Mutation.
Uncontrolled cell division, tumor.
Enlarged lymphnodes, liver, spleen, microscopically – lymphoma cells.
Fever, Wt loss, tumor-Ln, Liver, Spleen.