What system are the trachea, bronchi or bronchioles, air sac, and diaphragm in?
The respiratory system focuses on supplying all the tissues in our body with oxygen for respiration, and removing toxic waste products like carbon dioxide.
The trachea (or windpipe) brings air that you have breathed into the bronchi (there are two primary bronchi - one for each lung). From here, they enter the lungs and travel along secondary and tertiary bronchi into smaller bronchioles (just small tubes) and finally into the alveoli - gas sacs . Here, oxygen diffuses across into the bloodstream.
The diaphragm is also part of the respiratory system though. It is a large muscle in your chest that is lowered to increase the size of the chest cavity and thus lower pressure in the lungs. As there is now a lower pressure inside than outside, air is sucked into the lungs. It is then forced back out when the diaphragm moves back up.