Topic: Respiratory SystemAim: Describe the parts & functions of

the Respiratory System.

Do Now: Why do we breathe?

HW:

Did you know…• Every minute you breathe in 13 pints of air.• The blast of air being released during a

cough comes out speeds greater than 100 miles per hour.

• During sneezing, secretions of the nose are being expelled as droplets (more than 6,000) up to 10 feet at very high speeds (up to 40 miles per hour).

• People tend to get more colds in the winter because we're indoors more often and close to other people. When people sneeze, cough and even breathe, germs go flying!

Function •GAS EXCHANGE of O2 & CO2 bw organism & environment

Path of Air

1. Nose

•Nasal cavity

•Warms, moistens, filters air•ciliated mucus membrane

Usually a sneeze is started by tickling or irritation of the nerve endings of the membranes lining the inside of your nose. The sneezing reflex is useful in blowing out of your nose any dust particles causing irritation. It is an involuntary, sudden, violent, audible expulsion of air through the nose and mouth.

2. Pharynx

•Throat•Cavity in back of mouth

3. Epiglottis

•Covers trachea when swallowing to prevent choking

4. Larynx

•Voice box

•Contains vocal cords (produce sound)

http://www.youtube.com/watch?v=Z_ZGqn1tZn8

5. Trachea

•Windpipe

•Made of rings of cartilage (hold it open)

•Lined with cilia & mucous

6. Bronchi

•Two main branches enter lungs

•Lined with cartilage & cilia

7. Bronchioles

•Very small tubes•End at alveoli

Coughing is an important part of the body’s defense system. It forcefully propels unwanted invaders up and out of the body. Coughing is a reflex action started by stimulation of nerves in the lining of the respiratory tubes we use to breathe. The blast of air being released comes out scrubbing and clearing the airway of dust, dirt or excessive secretions. Maindex

8. Alveoli

•Air sacs•Where gas exchange occurs

•Surrounded by capillaries

Gas exchange

a. Alveoli fill up O2

b. O2 DIFFUSES into capillaries

c. CO2 & H2O vapor DIFFUSES out of capillaries into alveoli

•Sheet of muscle under lungs

•Aids in breathing

A

B

C

D

EF

G

H

I

Breathing•Inhalation air travels INTO lungs

•Exhalation air pushed OUT OF lungs

•Involves the diaphragm & rib cage muscles

Inhalation

•Diaphragm moves DOWN (contracts)

•Rib cage expands•Less pressure•Air rushes in

Exhalation

•Diaphragm moves UP (relaxes)

•Rib cage relaxes•More pressure•Air forced out

What controls breathing rate?

•Brain MEDULLA–Detects the level of CO2 in the blood

Let’s summarize:

1. Explain the function of the respiratory system.

2. List the structures air passes through when you inhale.

3. Explain the function of the ciliated mucus membrane.

4. Identify the structure that produces sound.

5. Why are the trachea and bronchi lined with cartilage?

6. Where does gas exchange occur?

7. Describe the process of gas exchange.

8. Describe how the diaphragm helps you breathe.

9. Which gas regulates breathing rate?

A

B

C

Review: Put the following structures in order to show the path of air when inhaling.

Larynx

Bronchi

Trachea

Alveoli

Nasal cavity

Bronchioles

Pharynx

In sensitive people, asthma symptoms can be triggered by breathing allergens. Common allergen triggers include:

• Animals (pet hair or dander)

• Dust

• Mold

• Pollen

• Chemicals in the air or in food

• Tobacco smoke

Other asthma triggers include:

• Changes in weather (most often cold weather)

• Exercise

• Respiratory infections, such as the common cold

• Strong emotions (stress)

• Bronchitis is an inflammation of the bronchial tubes. It causes a cough that often brings up mucus, as well as shortness of breath, wheezing, and chest tightness. There are two main types.

• With chronic bronchitis, the inflamed bronchi produce a lot of mucus which leads to cough and difficulty getting breathing. It is most often cased by cigarette smoke. Breathing in other fumes and dusts over a long period of time may also cause chronic bronchitis. This a long-term condition that keeps coming back or never goes away completely.

• Acute bronchitis can be caused by viruses or bacteria. These viruses spread through the air when people cough, or through physical contact (for example, on unwashed hands). Most cases of acute bronchitis get better within several days.