Breathing In (Inhalation)
When you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. This increases the space in your chest cavity, into which your lungs expand. The intercostal muscles between your ribs also help enlarge the chest cavity. They contract to pull your rib cage both upward and outward when you inhale.
As your lungs expand, air is sucked in through your nose or mouth. The air travels down your windpipe and into your lungs. After passing through your bronchial tubes, the air finally reaches and enters the alveoli (air sacs).
Through the very thin walls of the alveoli, oxygen from the air passes to the surrounding capillaries (blood vessels). A red blood cell protein called hemoglobin (HEE-muh-glow-bin) helps move oxygen from the air sacs to the blood.
At the same time, carbon dioxide moves from the capillaries into the air sacs. The gas has traveled in the bloodstream from the right side of the heart through the pulmonary artery.
Oxygen-rich blood from the lungs is carried through a network of capillaries to the pulmonary vein. This vein delivers the oxygen-rich blood to the left side of the heart. The left side of the heart pumps the blood to the rest of the body. There, the oxygen in the blood moves from blood vessels into surrounding tissues.
(For more information on blood flow, go to the Health Topics How the Heart Works article.)
Breathing Out (Exhalation)
When you breathe out, or exhale, your diaphragm relaxes and moves upward into the chest cavity. The intercostal muscles between the ribs also relax to reduce the space in the chest cavity.
As the space in the chest cavity gets smaller, air rich in carbon dioxide is forced out of your lungs and windpipe, and then out of your nose or mouth.
Breathing out requires no effort from your body unless you have a lung disease or are doing physical activity. When you're physically active, your abdominal muscles contract and push your diaphragm against your lungs even more than usual. This rapidly pushes air out of your lungs.
The animation below shows how the lungs work. Click the "start" button to play the animation. Written and spoken explanations are provided with each frame. Use the buttons in the lower right corner to pause, restart, or replay the animation, or use the scroll bar below the buttons to move through the frames.
Answer:
<h3>A. Quackery</h3>
Explanation:
Quackery is practicing medicine, or other accredited health professions by a dishonest or an incompetent person with little or no professional preparation to do what he claims he can do.
A person who promotes or sells health product or service that is unproven or ineffective is describing as quack.
Quackery is a type of medical fraud that plays on human emotion, weakness, and fear.
So, the correct answer is "A. quackery".
Foodbourne illness could get customers sick if the fruit is touched by others
Answer:
The correct answer is - Changing PRF.
Explanation:
Pulsed wave Doppler uses the principle of Doppler effect that objects that move changes the characteristic of sound waves. It is creates images by sending the short and quick pulses of the sound, it helps in the determining the velocity of blood in a exact time and location.
PRF or pulse repetition frequencies, is a Doppler sampling frequency that can affect the acoustic exposure of the scanning. PRF is measured in KHz.
Thus, the correct answer is - changing PRF.
