Transcript 02 the contents of pathology

The
contents of pathology
 Aetiology




(the causes )
Pathogenesis (mechanisms)
pathologic changes: structural & functional
abnormalities
the descriptions of the manifestations
its progress and sequelae.
1. Causes of disease
Identification of the causative factors that initiate the
disease process.
1). Genetic factors
2). Environmental factors
Although the causes of disease are divided into above two main
groups, but both groups are interlaced in most diseases.
2. Pathogenesis
Defining the disease mechanisms.
How do the causative factors change normal physiological
processes?
How do these functional changes cause changes in tissue
structure?

Most are still investigating. Some of them should
be known, for instance:
 Thrombosis
 Myocardial infarction
3. Pathologic changes
What are the specific changes in function and
structure that characterize each disease?
Level A. Naked eye level:
gross changes in diseased organs.
Level B. Light microscopic level:
in histological and cytological level.
Level C. Electron-microscopic(EM) level:
in the ultrastructure (cellular organelles).
Level D. Molecular level:
inspect aberrant in DNA, RNA, and protein.
4. Manifestations
The functional consequences of the morphologic changes.
Can these changes from normal be detected by clinical tests such as
examination of the blood or urine?
Can the structural changes be identified by techniques such as x-ray,
ultrasound, nuclear medicine, or examination of tissue samples
(biopsies)?
What clinical signs and symptoms are produced by the disease process?
How does the disease process produce these signs and symptoms?
5. Progress and sequels
 Progress
simple
short-term
intricate
long-term
 Sequels
healing
un-healing: delay & complications
spread even death
TASKS OF A PATHOLOGIST
In medical practice, the objective of the study of disease
has several purposes:
 Diagnosis: to determine the nature of the disease
process and its causation, i.e. to establish a diagnosis if
possible.
 Treatment: To monitor the extent and progress of the
disease and provide an indication of prognosis.
Treatment of the patient's disease is very often based
on this information.
 Prevention: To use knowledge of the mechanisms of
disease to prevent disease in individuals or populations
of people or animals.
The classification of pathology

General pathology: A discussion of disease
fundamentals oriented horizontally (nature of process).
injury, repair, inflammation, neoplasia.

Systemic pathology: A more detailed discussion of
diseases oriented vertically.
i. e. cardiovascular
diseases, respiratory diseases, alimentary diseases,
endocrine diseases, renal diseases, infectious diseases.
e.g. What is the commonest disease in the clinic:
trachoma, common cold, gastritis, hepatitis,athlete's foot
The location and importance of
pathology in medical education
Pathology is a bridge between basic science and clinical medicine.
All of the medical students have to stride over the bridge!