The Respiratory System Basic function: to enable body cells to be supplied with oxygen and rid the body of carbon dioxide.

Between and breaths a day Take a deep breath  You just captured 3-4L of air in your lungs! Breathing is so important that it cannot be left to conscious control

Nasal Cavity Nose Mouth Bronchus Bronchiole Alveolus Diaphragm Throat (pharynx) Windpipe (Trachea) Lungs Ribs

The Passage of Air Through the Upper Respiratory Tract: Nostrils/mouth  Nasal passages  Pharynx (Epiglottis = opening to trachea)  Enters the trachea  Glottis  Larynx  Continue down the trachea…

Turbinate Bones Very thin Project into the nasal passages Increase the SA of these chambers Have a thin membrane that secretes mucus  Moistens air  Traps particles (dust, bacteria, foreign matter)  Ciliated cells found in the membrane move particles into the nose or throat to be expelled by sneezing of coughing Capillaries (in the lining of the turbinates) supply warm blood to the nasal passages.  Heat air to body temperature to protect delicate structures in lower respiratory tract from damage by cold air.

Pharynx Pharynx (throat) is a passageway behind the mouth that connects the mouth and nasal cavity to the larynx and esophagus Air is then passed down to your trachea (windpipe)

Glottis Opening of the trachea through which air enters the larynx Can be closed by the epiglottis

Larynx Made of cartilage (tough, firm connective tissue) Used for sound production in mammals - contains vocal cords  Two folds of membrane stretched across the larynx During normal breathing muscular tissue holds vocal cords apart and air passes freely through Sound: cords are moved closer together and pressure from the air expelled causes them to vibrate  Pitch: varies with length of vocal cords.  Long cord (low sound), shorter cord (higher sound)  *Puberty: male vocal cords grow quickly, often causing a breaking quality in the voice. This disappears once finished growing Air continues down the trachea after the larynx

Trachea A flexible tube that carries air from nasal passages/mouth  bronchi and then to lungs Held open by semi-circular rings of cartilage  ~10-12 cm long from throat to middle of chest where it splits

Bronchi  Bronchioles Trachea splits up into two bronchi tubes. These two tubes keep splitting up and form your bronchioles. They get smaller and smaller and end with small air sacs called alveoli…

Lungs and Pleura Left vs. right lung…? Pleural membrane: thin, flexible, double-layered sac surrounds the lungs  Outer layer attaches to the inside of the chest wall  Inner layer covers the lungs  Thin space between has lubricating fluid that allows the layers to slide easily against each other during breathing

Alveoli Alveoli: these tiny air sacs = site of gas exchange Capillaries surround them Walls and capillaries are only one-cell thick! O 2 and CO 2 diffuse through, traveling into/out of blood stream ~500 million in an average adult human lung

Gas Exchange at the Alveoli

HOW TO WRITE A LAB REPORT 1. Title Page (Title, name, date etc.) 2. Purpose and Introduction 3. Hypothesis 4. Materials 5. Procedure 6. Observations/Results (tables and graphs here) 7. Discussion 8. Conclusions 9. Answers to Textbook Questions (pg. 447 #1-4) 10. References

Measuring Respiratory Volume Lab 1. Investigate your respiratory volume using a spirometer provided 2. Follow procedure on pg Record your observations 4. Discuss why you observed what you did with your partner 5. Upload your respiratory volumes to the class wiki before the end of tomorrow’s class – we will generate a class graph to include in your lab report 6. Write up your formal lab report due Friday March 9 th ( or Tuesday by … )