ScienceIQ.com

What are Hoodoos?

Hoodoos or Goblins are one of the most spectacular displays of erosion. They are geological formations, rocks protruding upwards from the bedrock like some mythical beings, conveying the story of hundreds and thousands of years of weather erosion. ...

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WhatareHoodoos
Physics

Newton's Three Laws of Motion

The motion of an aircraft through the air can be explained and described by physical principals discovered over 300 years ago by Sir Isaac Newton. Newton worked in many areas of mathematics and ... Continue reading

NewtonsThreeLawsofMotion
Physics

Your Serve

NASA is well known for developing technology that makes things better, so can you believe that NASA actually did research on how to make tennis balls slower? ... Continue reading

YourServe
Biology

What are Bacillariophyta?

Bacillariophyta are diatoms. All diatoms are single-celled organisms. They are microscopic, glassy organisms that photosynthesize for food, like plants. Diatoms live in the sediments of freshwater, ... Continue reading

WhatareBacillariophyta
Biology

The Limbic System

The limbic (meaning 'ring') system is virtually identical in all mammals. It sits above the brain stem, resembling a bagel with a finger (the brain stem) passing through it. This limbic 'system' ... Continue reading

LimbicSystem

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.