lined with a mucous membrane that helps keep your nose moist by making mucus so you won't get nosebleeds from a dry nose.

helps to regulate the temperature and humidity of the air your breathe in, as well as to lighten the bone structure of the head and to give tone to your voice.

air can enter in your mouth, especially if you have a mouth-breathing habit or your nasal passages may be temporarily blocked.

overgrown lymph tissues at the top of the throat. When your adenoids interfere with your breathing, they are sometimes removed.

lymph nodes in the wall of your pharynx. Tonsils are not an important part of the germ-fighting system of the body. If they become infected, they are sometimes removed.

collects incoming air from your nose and passes it downward to your trachea

flap of tissue that guards the entrance to your trachea. It closes when anything is swallowed that should go into the esophagus and stomach.

contains your vocal cords. When moving air is breathed in and out, it creates voice sounds.

passage leading from your mouth and throat to your stomach.

the passage leading from your pharynx to the lungs.

is the strong wall of muscle that separates your chest cavity from your abdominal cavity. By moving downward, it creates suction to draw in air and expand the lungs.

help oxygen from the air we breathe enter the red cells in the blood. Red blood cells then carry oxygen around the body to be used in the cells found in our body. The lungs also help the body to get rid of CO2 gas when we breathe out.

The trachea divides into the two main bronchi (tubes), one for each lung. The bronchi, in turn, subdivide further into bronchioles.

The smallest section of the bronchi are called bronchioles, at the end of which are the alveoli (plural of alveolus).

the very small air sacs that are the destination of air that you breathe in.

blood vessels that are imbedded in the walls of the alveoli.

Your airways narrow and make too much mucus.

Inflammation and infection make your bronchial walls thicker.

This long-term condition gets worse over time. It includes bronchitis and emphysema.

An infection causes inflammation in your alveoli. They might fill up with fluid or pus.

A bacterium causes this dangerous infection. It usually affects your lungs but might also involve your kidney, spine, or brain.

Cells in your lung change and grow into a tumor. This often happens because of smoking or other chemicals you’ve breathed in.

This disease is caused by a problem in your genes and gets worse over time. It causes lung infections that don’t go away.

Too much fluid builds up between the tissues that line your lungs and chest.

Your lung tissue becomes scarred and can’t work the way it should.

Tiny clumps of inflammatory cells called granulomas form, often in your lungs and lymph nodes.

Clear plastic drink bottle (A Gatorade bottle is a good size)

Two balloons

Tape (masking tape or duct tape)

Scissors

Measure an inch or two from the bottom of the plastic bottle and cut the bottom off carefully.

Take one balloon and put it inside the bottle. Then fold the bottom of the balloon around the rim of the bottle so the balloon hangs from the top. Wrap tape around the top if the balloon doesn’t seem snug around the bottle opening. You don’t want any air escaping, so make sure it is nice and tight!

Tie a knot at the end of the remaining balloon and cut the large part of the balloon in half horizontally.

Using the balloon half with the knot, stretch the open end over the bottom of the bottle. Again, this should be a tight fit. Use tape to secure if necessary.

Gently pull down on the balloon from the knot. This should cause air to flow into the balloons within your lung model.

Release the balloon with the knot and watch as the air is expelled from your lung model.