How does the human body feel after getting an electric shock?

Electric shock is a kind of injury caused by tissue burn or dysfunction of internal organs caused by current passing through human body.

The heat generated by electric current passing through body tissues can severely burn and destroy body tissues. Electric shock will short-circuit the human body's own conduction system, leading to cardiac arrest.

aetiology

Electric shock may be caused by lightning, touching household wires, broken wires in accidents, touching some charged objects, etc. The severity from mild burn to death depends on the type and intensity of current, the resistance of the electric shock site, the path of current through the human body and the duration of electric shock.

Generally speaking, direct current (DC) is not dangerous to alternating current. The influence of alternating current on the body depends largely on the frequency of current, measured in cycles per second (hertz). Low-frequency current of 50 ~ 60 Hz is widely used in the United States, which is more dangerous than high-frequency current and 3 ~ 5 times more dangerous than direct current with the same voltage and current intensity (ampere). Direct current usually causes strong muscle contraction, which often forces the victim to leave the power supply. 60 Hz alternating current makes the muscles of the electric shock area stiff, which often makes the victim unable to leave the power supply, thus prolonging the electric shock time and causing serious burns. Whether it is AC or DC, the higher the voltage and current intensity, the greater the damage.

The current intensity is in ampere, and the milliampere (mA) is11000 ampere. People's hands can feel 5 ~ 10 ma DC; You can also feel 1 ~ 10 mA and 60 Hz AC (sensing threshold). The maximum current that can make the arm muscles contract but still allow the hand to leave the power supply is called "discharge" current. The "release" current of direct current is about 75mA, and the "release" current of alternating current is 2 ~ 5~7mA for children, 5~7mA for women and 7 ~ 9 mA for men according to the size of arm muscles.

60 ~ 100 ma, 1 10 ~ 220 volts and 60 Hz alternating current pass through the chest instantly, which may cause life-threatening arrhythmia. The direct current that causes the same result is about 300 ~ 500 ma. If the current passes directly through the heart, such as through a pacemaker, very low current (less than 1mA) can also lead to arrhythmia.

Resistors have the function of preventing or slowing down the flow of current. The human body's resistance is mainly concentrated on the skin, which is directly related to the skin condition. The average resistance of dry healthy skin is 40 times that of thin and moist skin. When the skin is cut, scratched or electric current passes through moist mucous membranes, such as mouth, rectum and vagina, its resistance value is only half of that of moist intact skin. The resistance of palm or sole with thick cocoon may be 100 times that of thinner skin area. When current passes through the skin, it touches the resistance of the skin, and most of the energy is released on the skin surface. If the skin resistance is high, it can burn a large area at the inlet and outlet of current, and the tissue between them will carbonize. Depending on the resistance, internal tissues may also burn.

The path of current through the body is the key to the degree of injury. The most common place where electricity enters the body is the hand, followed by the head. Most of the parts where electricity flows out of the body are feet. Because the current passes through the heart from arm to arm or from arm to foot, it is much more dangerous than from foot to ground. Current passing through the head can cause seizures, cerebral hemorrhage, respiratory arrest and psychological changes (such as short-term memory disorder, personality change, tension and sleep disorder), as well as arrhythmia. Eye injuries can lead to cataracts.

The duration of electric shock is also an important factor. The longer the electric shock time, the more serious the tissue damage. People who cling to the power supply may be severely burned, but people who are struck by lightning rarely have serious external or internal burns, because lightning strikes happen in an instant, and the current flashes in the body, which will not cause serious damage to internal tissues. However, lightning can cause a short circuit between the heart and lungs, paralyze the heart and lungs, and may damage the nerves and brain.

. symptom

Symptoms depend on the complex interaction of various factors. Electric shock may make people suddenly frightened and fall down or cause strong muscle contraction. Both of these conditions may lead to joint dislocation, fracture and blunt trauma. Patients may also lose consciousness, respiratory paralysis and cardiac arrest. The electric burn of skin is obvious, and it can also spread to deep tissue.

High-voltage current will lead to tissue necrosis between the current inlet and outlet, and lead to large-scale muscle burn. A large amount of fluid and electrolyte loss, coupled with severe burns, will lead to dangerous hypotension. Injured muscle fibers release myosin, which can lead to kidney damage and renal failure.

People who are wet are exposed to electricity, such as when taking a shower, the hair dryer falls into the bathtub or steps on the charged pool. At this time, the skin resistance is low. Although there is no burn, it will cause cardiac arrest, and if it cannot be recovered quickly, it may die.

Lightning strikes rarely cause burns at entrances and exits, muscle damage and myoglobinuria. At first, you may lose consciousness, followed by coma and temporary mental disorder, which usually disappears within a few hours or days. The main causes of death from lightning stroke are heartbeat and respiratory arrest.

Toddlers may burn their lips by sucking the telephone line. This kind of burn will not only lead to facial deformity, but also lead to developmental disorders of teeth, mandible and face. Children with such burns should be treated by orthodontists, oral surgeons or burn doctors. 7 ~ 10 days after lip burn, it may cause massive bleeding of labial artery due to scab shedding, which is dangerous.