How do we obtain oxygen to break down (combust) our food?inhaledrink waterabsorption through the skin

We obtain oxygen to break down our food primarily through inhalation. Here's the step-by-step process:

1. Inhalation: When we breathe in, we inhale oxygen from the air around us. This oxygen enters our lungs.

2. Gas Exchange: Inside the lungs, the oxygen is transferred to red blood cells by a process called gas exchange. This happens in tiny air sacs in the lungs called alveoli.

3. Circulation: The oxygen-rich blood then travels from the lungs to the heart, which pumps it out to the rest of the body.

4. Cellular Respiration: Once the oxygen reaches our cells, it is used in a process called cellular respiration. This is where the food we eat is broken down to produce energy. Oxygen is a key player in this process, as it helps to break down glucose (from food) into water, carbon dioxide, and energy.

5. Exhalation: The waste products of this process, water and carbon dioxide, are then exhaled from our bodies when we breathe out.

Drinking water and absorption through the skin do not provide us with the oxygen needed for this process.