Topic: Respiratory System Aim: Describe the processes of gas exchange and breathing. Do Now: Describe the path of air when you inhale. HW:

nose mouth larynx lung bronchi diaphragm pharynx trachea bronchi bronchioles alveoli

Did you know… Your lungs contain almost 1500 miles of airways and over 300 million alveoli. During normal breathing, the speed that you exhale air is about 4 miles per hour. Plants are our partners in breathing. We breathe in air, use the oxygen in it, and release carbon dioxide. Plants take in carbon dioxide and release oxygen.

Gas exchange a. Alveoli fill up O 2

b. O 2 diffuses into capillaries c. CO 2 & H 2 O vapor diffuses out of capillaries into alveoli

Inside of alveolus O2O2 CO 2

Diaphragm

Sheet of muscle under lungs Aids in breathing

When your diaphragm becomes irritated, it pulls down in a jerky way, which makes you suck air into your throat suddenly. When the air rushing in hits your voice box, you're left with a big hiccup. Some things that irritate the diaphragm are eating too quickly or too much, excessive laughing, an irritation in the stomach or the throat, or feeling nervous or excited (breathing fast).

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

Maindex

REMEMBER… Inhale DOWN Exhale UP

What controls breathing rate?

Brain  MEDULLA –Detects the level of CO 2 in the blood

Let’s summarize…: 1.Where does gas exchange occur? 2.Describe the process of gas exchange. 3.Which way does the diaphragm move during inhalation? During exhalation? 4.What happens to pressure in the chest cavity during inhalation? During exhalation? 5.Which gas regulates breathing rate?

BELL JAR MODEL OF THE RESPIRATORY SYSTEM = TRACHEA 2 = BRONCHI 3 = ALVEOLI 4 = DIAPHRAGM

BELL JAR MODEL OF THE RESPIRATORY SYSTEM INHALATIONEXHALATION

BELL JAR MODEL OF THE RESPIRATORY SYSTEM INHALATIONEXHALATION Diaphragm moves DOWN Pressure decreases Air enters Diaphragm moves UP Pressure increases Air forced up & out