PATHOLOGYPATHOLOGY

Assist. Prof. Dr. Nadya Y. Ahmed

ReferenceReference

• Robbin’s Pathologic Basis of disease• 10th edition,2010

Where there is love of medicine,

there is love of

humankind

PATHOLOGYPATHOLOGYPathos (suffering)

Logos

PATHOLOGYPATHOLOGY

is the scientific study of disease or is is the scientific study of disease or is the study of the study of structuralstructural ( (morphologicalmorphological) )

and and functionalfunctional((physiologicaphysiological) l) abnormalities that are expressed as abnormalities that are expressed as

diseases of organ and systemdiseases of organ and system

CLINICAL/FUNCTIONALCLINICAL/FUNCTIONAL

Rudolph Virchow

1821-1902

The Father of Modern Pathology

PATHOLOGYPATHOLOGY•GENERAL•SYSTEMIC

Cores of pathologyCores 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)

•WHAT HURTS CELLS?

Causes of Cell InjuryCauses of Cell Injury

• Oxygen Deprivation• Physical Agents• Chemical Agents and Drugs• Infectious Agents• Immunologic Reactions• Genetic Derangements• Nutritional Imbalances

O2 insufficiency (↓PO2)O2 insufficiency (↓PO2)which impairs aerobic respiration & the ability to produce ATP. which impairs aerobic respiration & the ability to produce ATP.

This is a common cause of cell death.This is a common cause of cell death.• a. Hypoxia- lack of O2 results in decreased a. Hypoxia- lack of O2 results in decreased

aerobic respirationaerobic respiration• b. Ischemia- lack of O2 & metabolic substratesb. Ischemia- lack of O2 & metabolic substrates

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).

• 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

Physical AgentsPhysical Agents

• Mechanical trauma• Extremes of temperature – burns, deep

cold• Radiation• Electric shock

Chemical Agents and DrugsChemical Agents and Drugs

• Drugs & hypertonic concentration of salt – deranging electrolyte homeostasis

• Poisons – arsenic, cyanide, or mercuric salts

• Insecticides and Herbicides• Air pollutant – carbon monoxide• Occupational hazard – asbestos• Alcohol and Narcotic drugs

Causes of Cell InjuryCauses of Cell Injury

Infectious AgentsInfectious Agents

• Parasites• Fungi• Bacteria• Rickettsiae• Viruses

Causes of Cell InjuryCauses of Cell Injury

Immunologic ReactionsImmunologic Reactions

• Anaphylactic reaction to foreign protein or drug

• Reactions to endogenous self-antigens – autoimmune diseases

Causes of Cell InjuryCauses of Cell Injury

Genetics DerangementsGenetics Derangements

• Congenital malformation – Down’s syndrome

• Decreased life of red blood cell – Thalassemia, Sickle cell anemia

• Inborn errors of metabolism

Causes of Cell InjuryCauses of Cell Injury

Nutritional ImbalancesNutritional Imbalances

• Protein-calorie deficiencies• Vitamin deficiencies• Anorexia nervosa• Excesses of lipids – Obesity,

Atherosclerosis• Metabolic diseases – Diabetes

Causes of Cell InjuryCauses of Cell Injury

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