It is not just the muscle cells that respire. All cells in the body need oxygen for respiration and all cells need to get rid of the carbon dioxide that they produce. In the lungs oxygen is taken from air into the blood and the blood transports the oxygen to the cells in all tissues of the body.As the muscles use the oxygen up,carbon dioxide is produced and absorbed into the blood. And this de-oxygenated blood is pumped back to the heart then on to the lungs. The lungs get rid of this carbon dioxide, and breathe in more oxygen.
Hope this answered your question.
I believe the second answer is correct.
X-rays
used to measure bone density.
<u>Explanation</u>:
The bones density test measured by the X-rays, it measures the content of calcium and other bone minerals that are packed into the segment of bone. Most commonly used parts of bone for testing are spine, hip, occasionally and the forearm. It is generally done to know the chances of osteoporosis. More the bone minerals, more will be density. More density means the higher bone strength. Before the test, a person should avoid having calcium supplement.
<span>magnetic and electric fields are applied perpendicular to each other
Microwaves are electromagnetic waves which are composed of magnetic and electric fields oscillating perpendicular to each other.</span>
Compact bone<span> is dense </span>tissue that gives<span> the </span>bone<span> much of its </span>strength<span>. </span>
