The respiratory system has many functions. Besides helping you inhale (breathe in) and exhale (breathe out), it:

• Allows you to talk and to smell.

• Warms air to match your body temperature and moisturizes it to the humidity level your body needs.

• Delivers oxygen to the cells in your body.

• Removes waste gases, including carbon dioxide, from the body when you exhale.

• Protects your airways from harmful substances and irritants.

The lungs are a pair of spongy, air-filled organs located on either side of the chest (thorax). The trachea (windpipe) conducts inhaled air into the lungs through its tubular branches, called bronchi. The bronchi then divide into smaller and smaller branches (bronchioles), finally becoming microscopic.

The bronchioles eventually end in clusters of microscopic air sacs called alveoli. In the alveoli, oxygen from the air is absorbed into the blood. Carbon dioxide, a waste product of metabolism, travels from the blood to the alveoli, where it can be exhaled.

Respiratory Diagram

Match the letters with the organ of the Respiratory System?

Letter A Nose

Letter B Trachea

Letter C Lungs

Letter D Diaphragm