How Your Body Breathes and Uses Energy

Cellular Respiration Explained

Respiration is the process in which glucose and oxygen are transformed inside the cell into water, carbon dioxide, and energy.

The goal is to transform glucose and oxygen into energy.

Gases involved are oxygen, which we use, and carbon dioxide, the result.

It happens inside the cell in the mitochondria.

Defining Metabolic Rate

Metabolic rate is an average of the amount of energy that a person needs. While sleeping, we spend energy in circulation, for development, breathing, and protection. We spend energy because the body is working constantly.

Function of the Breathing System

In breathing, gases are exchanged. Oxygen goes from the air to the blood, and carbon dioxide goes from the blood to the air.

Lining of the Respiratory Tract

This lining can be found in your nose and air passages, such as the trachea, bronchi, and bronchioles.

The mucus membrane is a layer of special cells which produce a sticky fluid called mucus. The mucus and cilia keep the lungs clean and reduce the chance of infections.

The Diaphragm and Breathing

It's a muscle that takes part in the process of breathing and is located between the thorax and the abdomen.

• Inhalation: It contracts and gets flatter, which makes the volume of the thorax increase. Pressure decreases, and air is pushed into the lungs.
• Exhalation: It relaxes, pressure increases so air can pass, the volume decreases, and it gets dome-shaped.

Air Pathway to the Lungs

The path followed by air from the atmosphere until it gets to the alveoli:

1. It enters through the mouth or nose.
2. Passes through the trachea.
3. When the diaphragm contracts, it passes through the bronchi and bronchioles.
4. Reaches the alveoli.

Gas Exchange in the Alveoli

In the alveoli, oxygen from outside goes to the blood, and carbon dioxide comes from the blood and goes outside.

The walls are very thin so gases can cross through them easily.