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.
What are Heart Muscle Diseases? The heart predominantly comprises billions of heart muscle cells or âcardiomyocitesâ. Heart muscle diseases are those disorders that directly affect heart muscle cells and cause inadequate pumping of the heart, known as heart failure. The early signs of heart failure are shortness of breath during mild exertion and, as the illness worsens, breathlessness even while simply sitting or lying down.