Some nebulae create their own light, which sometimes has a fluorescent appearance, while others only reflect the light from nearby stars. Nebulae are often seen around dying stars, and it's thought they may be a natural process that occurs when a star is nearing the end of its life. Nebulae resemble thin clouds that have less atoms per cubic inch than a cloud of smoke.
When there is not enough thyroid hormone, neither the heart nor the blood vessels can function normally. In hypothyroidism, the reduced level of thyroid hormone causes the heart muscle to pump less vigorously, and eventually to become weakened. In addition, the heart muscle cannot fully relax after each heart beat.
for a variety of reasons something causes the heart to beat out of control this abnormal heart rhythm is known as ventricular fibrillation some specific causes of sudden cardiac death in young people include hypertrophic cardiomyopathy hcmthis is a disease in which the heart muscle myocardium becomes abnormally thick making it harder for the heart to pump bloodome specific causes of sudden cardiac death in young people include hypertrophic cardiomyopathy hcm this is a disease in which the heart muscle myocardium becomes abnormally thick making it harder for the heart to pump blood