How does oxygen get from your nose to a muscle cell in your body?

Answer 1

Here is the path oxygen takes to get to the cells of the body:

Air enters the body through the nose (or through the mouth) and passes the epiglottis to the pharynx, then through the larynx (voicebox) on the way to the bronchi (air tubes) of the lungs. At the end of the smallest bronchioles are millions of air sacs called alveoli. Here, the oxygen in the air is picked up by the red blood cells of the blood. A protein called hemoglobin takes up oxygen and gives up carbon dioxide, which is the product of metabolism in the cells.

The blood comes to the lungs after passing through the right ventricle of the heart. This chamber takes the body's de-oxygenated blood and sends it to the lungs through the pulmonary arteries. Once the blood cells have oxygen again, they return to the heart through the pulmonary veins.

The blood enters the left atrium, then is pushed into the left ventricle, the powerhouse muscle of the heart. This shoves the blood out into the aorta, a large flexible artery. The pressure here forces the blood into the other arteries, which connect to even smaller arteries, which connect to the capillaries (the smallest blood vessels). The capillaries carry the red blood cells, with their oxygen, to every cell in the body. Once the oxygen is in a cell, it can be used in metabolism. The cell gives up its carbon dioxide to the red blood cells, which start their long trip back through the veins to the heart, and to the lungs for another supply of oxygen.