ScienceIQ.com

A Sweaty Subject

When human body temperature rises, tiny muscles around the sweat glands in the skin contract, squeezing perspiration - better known as sweat - out through the pores. Sweat is about 99 percent water. Dissolved in it are salts of sodium, potassium, and magnesium. Sweat also contains tiny amounts of waste materials such as urea (the major toxin in ...

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Sweat
Astronomy

Does The Sun Go A Bit Wobbly?

Our Sun may seem an enduring, unwavering beacon in the sky, but in truth it has a 'heartbeat' of sorts--a pulsation between dimmer and brighter phases so slow that it only 'beats' 9 times each ... Continue reading

WobblySun
Biology

What Are Stem Cells?

When an egg is fertilized by a sperm cell, it quickly becomes a single cell from which all cells of the body-to-be will be created. This 'mother of all cells' is what biologists call a totipotent stem ... Continue reading

StemCells
Geology

Our Most Abundant Fossil Fuel

Coal is our most abundant fossil fuel. The US has more coal than the rest of the world has oil. There is still enough coal underground in this country to provide energy for the next 200 to 300 years. ... Continue reading

OurMostAbundantFossilFuel
Chemistry

Chemical Burning

Chemical burns are the result of very normal reactions that can occur between the offending material and living tissue components. People generally tend to regard their bodies as things outside of the ... Continue reading

ChemicalBurning

Facts About Angina

FactsAboutAnginaAngina is a recurring pain or discomfort in the chest that happens when some part of the heart does not receive enough blood. It is a common symptom of coronary heart disease (CHD), which occurs when vessels that carry blood to the heart become narrowed and blocked due to atherosclerosis Angina feels like a pressing or squeezing pain, usually in the chest under the breast bone, but sometimes in the shoulders, arms, neck, jaws, or back. Angina is usually precipitated by exertion. It is usually relieved within a few minutes by resting or by taking prescribed angina medicine. Episodes of angina occur when the heart's need for oxygen increases beyond the oxygen available from the blood nourishing the heart. Physical exertion is the most common trigger for angina. Other triggers can be emotional stress, extreme cold or heat, heavy meals, alcohol, and cigarette smoking.

An episode of angina is not a heart attack. Angina pain means that some of the heart muscle in not getting enough blood temporarily--for example, during exercise, when the heart has to work harder. The pain does NOT mean that the heart muscle is suffering irreversible, permanent damage. Episodes of angina seldom cause permanent damage to heart muscle. In contrast, a heart attack occurs when the blood flow to a part of the heart is suddenly and permanently cut off. This causes permanent damage to the heart muscle. Typically, the chest pain is more severe, lasts longer, and does not go away with rest or with medicine that was previously effective. It may be accompanied by indigestion, nausea, weakness, and sweating. However, the symptoms of a heart attack are varied and may be considerably milder.

When someone has a repeating but stable pattern of angina, an episode of angina does not mean that a heart attack is about to happen. Angina means that there is underlying coronary heart disease. Patients with angina are at an increased risk of heart attack compared with those who have no symptoms of cardiovascular disease, but the episode of angina is not a signal that a heart attack is about to happen. In contrast, when the pattern of angina changes--if episodes become more frequent, last longer, or occur without exercise--the risk of heart attack in subsequent days or weeks is much higher.