Respiratory SystemChapter 18 Section 1

You Will Learn• To describe the structures and

functions of the respiratory system.

• To analyze the process of cellular respiration.

• To explain other functions of the respiratory system.

• To model how air moves in and out of the lungs.

The Respiratory System• During the day you eat only a

few times, but you breathe thousands of times.

• Your body cannot store much Oxygen.

• The Respiratory System works to get oxygen from the environment and remove carbon dioxide and other waste products from your body.

The Respiratory System•The respiratory system uses both mechanical and chemical reactions.

•Air transported in your lungs by a mechanical reaction.

•Oxygen used during chemical reactions to release energy in your cells!

Exchanging Oxygen & Carbon Dioxide

•Oxygen enters the body when you inhale

•Oxygen is then passed through the body through Red Blood Cells.

AIR• The air we breathe is about

20% Oxygen• About 80% of the air is

nitrogen gas• The air you exhale is mostly

Carbon Dioxide• Too much Carbon Dioxide in

your body will damage cells.

• So how do Scuba divers get the Oxygen they need to dive deep into the ocean?

Cellular Respiration• Uses Oxygen in chemical

reactions to release energy.Glucose + Oxygen Energy +

Water+ Carbon Dioxide

The Respiratory System works with the digestive and circulatory system to make cellular respiration possible

Carbon Dioxide is the waste product and is released from the body

Structures: Nose•Air enters through your nose.

•Tiny hairs called cilia filter dirt and other particles.

•Mucus also helps to filter.

•Warms Air

Structures: Throat•Tubelike Structure

•Also Known as the Windpipe or Trachea

•Air travels down on the way to the lungs.

Structures: Lungs•Located on either side of the heart•Air enters through the lungs into structures called bronchial tubes.•At the end of bronchial tubes are tiny sacs called alveoli.•Oxygen passes from the inside the alveoli through the thin walls and diffuse into the blood. CO2 also diffuses

Collapsed Lung

Structures : Ribs•Protects lungs

•Very Flexible

•Is able to expand to make room for the lungs to expand and fill with air.

Structure: Diaphragm• Stretches downward as you

inhale, which causes lungs to push downward.

• At the same time, other muscles draw the ribs outward and expand the lungs. Air rushes into the lungs, and inhalation is complete. When the diaphragm and other muscles relax, the process reverses and you exhale.

Other Functions•The respiratory System also allows the body to speak, sing, sneeze, & yawn

•Put your hand over your throat. Can you feel your vocal cords vibrating?

•The vocal cords are folds of tissues in the larynx.

The Respiratory System• You sneeze to clear particles out

of your nose

• A hiccup is a sudden inhalation that makes the diaphragm contract.– Air rushes in the throat– The Diaphragm contracts– The passageway between the vocal

cords closes– This causes the hiccup sound– Hiccups can be caused by eating

too fast, sudden temperature changes, and stress.

Did you Know•Your body disposes of water waste through the respiratory system through hiccups, yawning, coughs, etc.•Have you ever seen your breathe on a cold winter day? This is because the water vapor you exhale condenses into larger droplets when it moves from your warm body to the cold air.