5. PATHOLOGY
is the scientific study of disease or is
the study of structural (morphological)
and functional(physiological)
abnormalities that are expressed as
diseases of organ and system
8. Cores of pathology
• Etiology
• Pathogenesis. (sequence of events at the
organ, cellular, ultrastructural, and molecular
levels, from initial stimulus to the ultimate
expression of the disease.
• Morphologic changes. (Macro- &
microscopical changes).
• Signs & symptoms. ( Functional changes)
12. Causes of Cell Injury
• Oxygen Deprivation
• Physical Agents
• Chemical Agents and Drugs
• Infectious Agents
• Immunologic Reactions
• Genetic Derangements
• Nutritional Imbalances
13. O2 insufficiency (↓PO2)
which impairs aerobic respiration & the ability to
produce ATP. This is a common cause of
cell death.
• a. Hypoxia- lack of O2 results in
decreased aerobic respiration
• b. Ischemia- lack of O2 & metabolic
substrates
14. Hypoxia: Too little available oxygen in the blood
Oxygen problems ("hypoxic hypoxia")
Too little oxygen in the air
Failure to properly ventilate the lungs
Failure of the lungs to properly oxygenate the
blood
Failure of the heart to pump enough blood
through the lungs
Hemoglobin problems ("anemic hypoxia")
Inadequate circulating red cell mass
("anemia")
Inability of hemoglobin to carry the oxygen
(carbon monoxide poisoning).
15. • Ischemia ("ischemic hypoxia“ ) Loss of arterial
blood flow. ↓ O2 & nutrition to tissues
• Local causes
– Occlusion of the arteries that bring in fresh blood
– Occlusion of the veins which allow blood to leave, so
that fresh blood can flow in
• Systemic causes
– Failure of the heart to pump enough blood
19. Causes of Cell Injury
Immunologic Reactions
• Anaphylactic reaction to foreign protein or
drug
• Reactions to endogenous self-antigens –
autoimmune diseases
20. Causes of Cell Injury
Genetics Derangements
• Congenital malformation – Down’s
syndrome
• Decreased life of red blood cell –
Thalassemia, Sickle cell anemia
• Inborn errors of metabolism
The second most profound thing ever said, in the 2 nd millenium, after E=mc2, was by Rudolph Virchow. He said, “All diseases are the results of visible cell abnormalities”, i.e., abnormal histology, i.e., histopathology. For this, he earned the undisputed title of “father of pathology.”
