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Physical Injury (Mechanical Injury)
This Sqadia video is the demonstration of Environmental Pathology. Injury means mental or physical harm to a person caused by accident or disease. There are four types of physical injury:
- 1. Mechanical Injury
- 2. Thermal Injury
- 3. Electrical Injury
- 4. Radiation Injury
Mechanical injury is a type of injury caused by application of physical violence to the body. Mechanical injury includes Laceration, Puncture, abrasion or scrape. Hemorrhage, Ruptured Viscera, and secondary Infection, are causes of Death Secondary to Mechanical Injury. Blunt Force Injuries include Head Injury, Abdominal Injury, Thoracic Injury. In head injury brain damage is direct result of cerebral trauma, Brain Laceration is Caused by fracture with penetrating injury by skull fragments. Abdominal Injury is the rupture of intestine, Spleen or Liver. Thoracic Injury results in Rib Fracture, Hemothorax, and Pneumothorax. Knife Stab Wounds are Incisions or Puncture Wounds. There are several of types of Gunshot Wounds. Entrance wound is smaller and rounder than exit wound, maybe even smaller than the bullet due to elastic skin. Exit wounds significantly larger than the bullet due to tumbling of the bullet and are usually irregular and stellate. In contact wounds there may be burning around the margins of the wound (abrasion ring).
Physical Injury (Thermal, Electrical and Radioactive)
Thermal Injury include Burns and freezing. In First Degree Burns, there is no significant epidermal damage. In Second Degree Burns, blistering and destruction to the epidermis takes place. Third Degree Burns damages epidermis, dermis & dermal appendages and as a result skin and underlying tissue charred and blackened. In thermal injury, freezing may be generalized that results in death, or may be localized resulting in frostbite. Electrical injury is damage caused by electrical current passing through the body. The severity of electrical injury depends on Type of current DC or AC, Voltage and amperage, Duration of exposure, Body resistance and pathway of current. Radiation Injury is caused by ultraviolet light and ionizing radiations.
In the environment Chemical Abuse involves Alcohol Abuse, Tobacco Abuse, and Drug Abuse. Alcohol abuse is the important cause of death and disability from different causes ranging from automobile accident to homicides. Some severe disorders that arise due to the excessive alcohol uptake are: Myopathy, Gastritis, Alcoholic Hepatitis and cirrhosis. Tobacco Abuse is Associated with Squamous cell carcinoma of the larynx, squamous cell and small cell bronchogenic carcinoma, and transitional cell carcinoma of the bladder. Drug Abuse includes the use of Coccaine and Heroin.
Environmental Chemical Injuries
Carbon Tetra-Chloride (CCl4) is centrilolobular necrosis and fatty change in liver. Cyanide poisoning is a form of histotoxic hypoxia because the cells of an organism are unable to create ATP, primarily through the inhibition of the mitochondrial enzyme cytochrome c oxidase. Early symptoms include headache, dizziness, fast heart rate, shortness of breath, and vomiting. Long term complications of carbon monoxide poisoning may include feeling tired, trouble with memory, and movement problems. Known mechanisms include carbon monoxide binding to hemoglobin, myoglobin (high affinity) and mitochondrial cytochrome oxidase (low affinity) and restricting oxygen supply. In Methyl Alcohol Poisoning, methyl alcohol is converted to cellular toxins formaldehyde and formic acid resulting in transient metabolic acidosis. Lead Poisoning results from paint and automotive emissions and consequently Red Blood Cell changes and disorders like Neuropathy, Encephalopathy appears.
Adverse Effects of Therapeutic Drugs
Adverse Effects of Antibiotics include development of drug resistant organisms and Fatal aplastic anemia. Adverse Effects of Sulfonamides are Crystallization of sulfonamides within renal collecting system causing calculi with obstruction, infection or both, bone marrow failure. Adverse Effects of Analgesics such as Aspirin include Gastroduodenal Bleeding, Reye Syndrome. Phenacetin causes Chronic analgesic nephritis, renal papillary necrosis, and Acute hemolysis. Cancer Therapeutic Drugs causes damage to organs such as the thyroid gland, liver, or kidneys, and Acute leukemia and other malignancies.