The Respiratory System

Functions of the Respiratory System1) Moves oxygen from the outside

environment into the body,

2) Removes carbon dioxide and water from the body.

This is a cartoony image of your lungs, the main organs of the respiratory system!

Why the Body Needs OxygenYour body needs oxygen to keep you

alive, right? But why?Oxygen is a key player in respiration.Respiration is not breathing!Respiration is the process in which

oxygen and glucose undergo a complex series of chemical reactions inside cells.

This process of respiration is how your body creates energy for itself! Pretty cool, huh?

Homeostasis in Action!Remember this funny word?Now we know that our respiratory system

inhales oxygen for us when we breathe, but that oxygen wouldn’t go anywhere without the help of our circulatory system.

Also, our bodies couldn’t carry out respiration without glucose (sugar) that our digestive system breaks down.

Did You Know?The air you are breathing in right now is

made of a mixture of gases.Only about 21% of the air is oxygen.78% is nitrogen.

What percentage are we up to?The remaining 1% is made up of carbon

dioxide, helium, and various other gases.

Elements are pure chemical substances

Path of Air

Path of AirLuckily, your respiratory system is equipped

with tools so that less of that stuff gets in your lungs.

As air travels from the outside environment to the lungs, it passes through the following organs : nose, pharynx, trachea, and bronchi.

It only takes a few seconds!

Nose FunctionsHeats the air you breathe in.Produces mucus that traps dust and

bacteria.Contains cilia (hairs) that sweep the

mucus into the throatCauses you to sneeze so that dust

particles and bacteria leave the body.

Pharynx (FAR ingks)Known as your throatShared with the digestive systemBoth nose and mouth connect at the

pharynx.

Trachea (TRAY kee uh)Known as your windpipe.Made of thick rings of cartilage that

remain firm to strengthen the trachea and keep it open.Why do you think it’s not squishy like the

esophagus?Also lined with cilia and mucusAllows you to cough if there are dust or

bacteria irritating your windpipe.

Bronchi & LungsBronchi are the two main branches that

lead to the lungsBronchitis sound familiar?

Each bronchus leads into a lung where it branches out into smaller and smaller branches.

At the ends of the smallest tubes are bundles of “grapes” called alveoli.

Alveoli are tiny sacs of lung tissue specialized for the movement of gases between air and blood.

Gas ExchangeAfter air enters the alveoli, oxygen passes

through the wall of the alveoli and through the wall of a tiny blood vessel. Carbon dioxide and water pass from the blood into the alveoli.

DiaphragmA large dome-shaped muscle that plays an

important role in breathing located at the base of the lungs.

When you breathe in, the diaphragm moves down.

When you breathe out, the diaphragm moves up.

Larynx (LAR ingks)Known as the voice box at the top of

your trachea.Holds your vocal chords which produce

your voice.Think of the way a balloon squeaks when

you let air through the neck. That’s kind of how your vocal chords work.

Muscles makes your vocal chords contract and the movement makes the air molecules vibrate and create a sound!