shock, any condition in which the circulatory system is unable to provide adequate circulation to the body tissues, also called circulatory failure or circulatory collapse. Shock results in the slowing of vital functions and in severe cases, if untreated, in death. It may be caused by inadequate pumping by the heart, by reduction of the blood volume due to dehydration or to loss of blood or plasma, or by reduced blood pressure resulting from dilation of the blood vessels. Inadequate pumping may occur as a result of various kinds of heart disease. Blood loss may result from injuries or from such internal conditions as bleeding ulcers. Burns produce extensive plasma loss from blood vessels into the burned area; crush injuries may result in loss of blood and plasma into the injured tissues. Dilation of blood vessels may be caused by injury to the nervous system, or by pain or emotional stress. Fainting is a form of shock brought about by a sudden reduction of the blood supply to the brain. Symptoms of shock include weakness, pallor, cold and moist skin, and thirst. The arterial blood pressure is reduced, the pulse is weak and rapid, and the surface veins of the limbs may collapse. Emergency aid for shock victims includes maintaining a clear breathing passage, administering oxygen, controlling bleeding, and keeping the patient warm and in a supine position with legs elevated. Therapy may include blood or plasma transfusion to restore the normal circulation, as well as treatment of the underlying cause of shock. The term shock is also applied to a variety of other conditions such as electric shock, allergic shock (see anaphylaxis), and emotional shock. See first aid.

Bacterial disease caused by a toxin produced by the bacterium Staphylococcus aureus. It was first recognized in 1978 in women using superabsorbent tampons. High fever, diarrhea, vomiting, and rash may progress to abdominal tenderness, drop in blood pressure, shock, respiratory distress, and kidney failure. The syndrome also has other causes, including postsurgical infection. Antibiotics are not effective. With intensive supportive therapy, most patients recover in 7–10 days, but 10–15percnt die. Many patients have a milder recurrence within eight months.

Learn more about toxic shock syndrome with a free trial on Britannica.com.

formerly shock therapy

Method of treating psychiatric disorders by inducing shock through electric current. Electroconvulsive, or electroshock, therapy involves passing an electric current through the patient's head between two electrodes placed over the temples and thus causing a convulsive seizure; it was used to treat bipolar disorder and other types of depression. Shock was previously induced by administering increasingly large doses of insulin until the patient was thrown into a brief coma; the so-called insulin-shock therapy was used for the treatment of schizophrenia. Both forms of shock therapy were developed in the 1930s. Their use declined after the introduction of tranquilizing drugs and antidepressants.

Learn more about electroconvulsive therapy with a free trial on Britannica.com.

Device for controlling unwanted motion of a spring-mounted vehicle. On an automobile, the springs act as a cushion between the axles and the body and reduce the shocks produced by a rough road surface. Since some combinations of road surface and car speed may result in excessive up-and-down motion of the car body, shock absorbers—which today are hydraulic devices that oppose both compression and stretching of the springs—slow down and reduce the magnitude of these vibratory motions. Seealso damping.

Learn more about shock absorber with a free trial on Britannica.com.

State in which the circulatory system fails to supply enough blood to peripheral tissues to meet basic requirements. Symptoms—weak, rapid pulse; low blood pressure; and cold, sweaty skin—are not all present in every case. Causes include low blood volume, caused by bleeding or fluid loss from burns or dehydration; inability of the heart to pump enough blood, due to heart attack, pulmonary embolism, or cardiac tamponade (compression of the heart by fluid in the membrane around it); and blood-vessel dilation as a result of septicemia, allergy (including anaphylaxis), or drugs. All result in reduced capillary blood flow; reflexes increase heart rate and constrict small blood vessels to protect the blood supply to essential organs. Without treatment of the underlying cause, these mechanisms fail; since the cause is not always clear, cases tend to require different and occasionally contradictory treatment (e.g., intravenous fluids can save the life of a patient with massive blood loss but can overload a weakened heart).

Learn more about shock with a free trial on Britannica.com.

Physical effect of an electric current that enters the body, ranging from a minor static-electricity discharge to a power-line accident or lightning strike but most often resulting from house current. The effects depend on the current (not the voltage), and the worst damage occurs along its path from the entry to the exit point. Causes of immediate death are ventricular fibrillation and paralysis of the brain's breathing centre or of the heart. Cardiopulmonary resuscitation is the best first aid. Though most survivors recover completely, aftereffects may include cataract, angina pectoris, or nervous-system disorders.

Learn more about electric shock with a free trial on Britannica.com.

Severe, immediate, potentially fatal bodily reaction to contact with a substance (antigen) to which the individual has previously been exposed. Often triggered by antiserum, antibiotics, or insect stings, the reaction's symptoms include skin flushing, bronchial swelling (with difficulty breathing), and loss of consciousness. Shock may follow. Milder cases may involve hives and severe headache. Treatment, consisting of injection of epinephrine, followed by antihistamines, cortisone, or similar drugs, must begin within minutes. Anaphylaxis may be caused by extremely small amounts of antigen.

Learn more about anaphylaxis with a free trial on Britannica.com.

G-Shock is a brand of watches manufactured by Casio, known for its resistance to shocks (e.g. hard knocks and strong vibrations). They were, and continue to be, designed primarily for sports and outdoor adventure oriented activity; for example, practically all G-Shocks have some kind of stopwatch feature, countdown timer, light and water resistance. Recent models have become more luxury and design oriented.

Today

The G-Shock was first produced in 1983. The line has expanded considerably since then and now includes atomic clock synchronization and Tough Solar functionality in the latest models. The Cockpit Series G-Shock is currently the official timekeeper of Nismo Racing. Many newer G-Shocks feature metal (steel or titanium) banding, and ornate analog timekeeping.

Twice a year (Spring/Summer and Fall/Winter collection) the basic models are updated. New limited models are introduced more frequently through the year. As with Swatch watches, G-Shocks have become collectors items. Arguably, the most sought after line is the Frogman. Limited edition Frogmans such as the Brazilian, Men in Yellow, Black Helios and Black Spots are some of the most desirable Frogmans.

Different series were developed for different target groups. The G-Lide (in Japan called X-Treme) series is specially for extreme sports like Skateboarding, Surfing and Snowboarding.

Casio also produces collaboration models, often with popular fashion brands, like A Bathing Ape (Bape), Stussy, Xlarge, KIKS TYO, Nano Universe, Levi's as well as Coca Cola and Marlboro.

Also there are special models released to put attention on the environment, like the International Cetacean Education and Research Centre (I.C.E.R.C.)models, also known as the Dolphin and Whales models.

G-Shock is very popular by rescue workers, police, astronauts, firemen and military. According to Mark Bowden's book Blackhawk Down, the DELTA Operators wore G-Shock watches during the combat events of Oct 3rd and 4th. Since then, G-Shocks watches have become very popular with Special Forces groups in both American and other NATO nation units, due to their being "battle tested".

Casio released "G-Shock Official Book" in 2006 in Japan, reviving the interest of (mostly Japanese) G-Shock collectors.

Models/Series

Baby-G

Baby-G was created as an addition to the G-Shock brand. The Baby-G brand is a sports digital watch aimed at young teens. Like the G-Shock, it is rugged. But unlike the G-Shock it is smaller, more compact, comes in designer colors, and has an added tele-memo feature that allowed the user to store 25 sets of data in the watch. Casio later retrofitted this feature to some of the larger styles of the G-Shock brand. Two thirds of Casio's Baby-G sales are in Casio's domestic market in Japan.

Other

• Master of G
• Tough Solar
• Wave Ceptor
• DW-5000-5200
• DW-5600C
• DW-5600E
• DW-6900FS
• Cockpit Series
• G-Lide
• Giez
• Limited Models
• MT-G
• MR-G

Footnotes

External links

• Official Casio G-Shock website
• Official European Casio G-Shock website
• Official US Casio G-Shock website
• G-Shock fansite with loads of G-Shock information
• The Original G-Shock Forum
• Rare G-Shock 25th Anniversary Collaboration with KIKS TYO and New Balance
• Exclusive G-Shock "CONCRE" line featuring collaborations with NYC Artists, Retailers
• Manuals for Casio watches; requires Adobe Reader
• Casio Hong Kong Officical Wholesaler
• An unofficial G-Shock "torture test"
• Casio G-Shock Watch Index A very handy reference index of every G-Shock, listing by type, shape, case color, size, weight, module, water resistance, and model number.