Toxicology The Respiratory system. Toxicological perspectives Direct target of toxicity from...
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Transcript of Toxicology The Respiratory system. Toxicological perspectives Direct target of toxicity from...
ToxicologyThe Respiratory system
Toxicological perspectives
Direct target of toxicity from exposure to many airborne chemicals.
Provides an early warning detection system.Provides an exposure pathway for systemic exposure
to many toxicants.Is an important organ system for many xenobiotic
biotransformation.
Respiratory system
The average adult inhales approximately 12kg of air daily.
Incidents like the accidental release of 40 tons of methyl isocynates in Bhopal, India.
Handling and milling grain releases atmospheric dust that may provokes asthmatic attack.
Respiratory system play role in the recognition, metabolism, detoxification, elimination of xenobiotics
Lungs
The human lungs are the organs of respiration in humans.
Humans have two lungs, with the left being divided into two lobes and the right into three lobes.
Together, the lungs contain approximately 2,400 kilometers of airways and 300 to 500 million alveoli, having a total surface area of about 70 square meters in adults.
Each lung weighs 1.1 kilograms therefore making the entire organ about 2.3 kilograms.
Functional division of respiratory systemNasopharyngealTracheobronchialPulmonary
Mechanism action of aerosolized toxins
Inhalation of aerosolized toxin opening of sodium channels
release of neurotransmitters autonomic nerve ending
airway smooth muscles depolarization
contraction
Systemic toxicities through respiratory exposure
Carcinogens Poly aromatic hydrocarbon, vinyl chloride.
Hematoxicities Arsine, nitrobenzene, CO.
Nephrotoxicites Heavy metals, chloroform,CCl4.
Hepatotoxicites CCl4, ethanol.
CNS toxicants Acrylamide, mercury, acetone
Asphyxiants CO,N2,CH4.
Irritants NH3,NO2,SO2.
Nomenclature of airborne toxicants
GasesVaporAerosolsDustsFumesSmokeFogSmog
Respiratory system injury
Irritative or inflammatoryBronchoconstructiveFibroticOncogeneticNecrotic
Air pollutants
OZONE(O3) Sulfur dioxide(SO2) Nitrogen dioxide(NO2) Carbon monoxide (CO) Lead (Pb)
Asbestosis
Chronic Obstructive Pulmonary Disorder (COPD)
Centrilobular emphysema
Squamous cell carcinoma of the lung
Normal Chest X-Ray and Lung
Chest X-Ray and Diseased Lung
Bronchoscope