1. Respiratory System

2. Respiration Overview All of your body’s cells require oxygen (remember, oxygen and glucose are used by your cells during cellular respiration to make ATP or energy) The respiratory system supplies oxygen and removes carbon dioxide from your body

3. Overview cont. The respiratory system is made up of: Nasal passages Pharynx (upper throat) Larynx (voice box), Epiglottis (a flap of tissue that keeps food from getting into the windpipe/trachea) Trachea lungs, Bronchi Bronchioles Alveoli Diaphragm

4. The Path of Air First, air enters the mouth or nose. Hairs in the nose filter out dust and other large particles in the air Hair-like structures called cilia line the nasal passage (and other respiratory tubes), and trap foreign particles from the air and sweep them toward the throat so that they don’t enter the lungs. Mucous membranes beneath the cilia in the nasal massage warm and moisten the air while trapping foreign materials

5. Path of Air cont. The filtered air now passes through the upper throat (the pharynx). A flap of tissue called the epiglottis prevents food particles from entering the respiratory tubes (like the larynx) The epiglottis allows air to pass from the larynx to a long tube in the chest called the trachea (or windpipe)

6. Path of air cont. The trachea branches into two large tubes, called bronchi (singular is bronchus), which lead to the lungs The lungs are the largest organs in the respiratory system, and this is where gas exchange takes place Each bronchus branches into smaller tubes called bronchioles Bronchioles branch into even smaller passageways which end in an individual air sac called an alveoli (alveolus singular) Each alveolus has a thin wall – only one cell thick – and is surrounded by capillaries

7. Gas Exchange in the Lungs Air travels to individual alveoli, where oxygen diffuses across the thin capillary walls and into the blood cells The oxygen is then taken to cells in the body Carbon dioxide in the blood crosses the capillary walls and diffuses into the alveoli to be exhaled

8. Breathing The brain controls the rate of breathing by responding to internal stimuli that tell how much oxygen the body needs. When you have lots of CO2 in your blood, your breathing rate increases (because your cells need more oxygen) During inhalation (taking in oxygen), your diaphragm contracts, which causes the chest cavity to expand as the diaphragm moves down. This allows air to move into the lungs In exhalation, the diaphragm relaxes, reduces the size of the chest cavity and air naturally flows out from the greater pressure of the lungs

9. Assignment: Draw a Venn Diagram that illustrates THREE differences and similarities between the respiratory system and circulatory system Fill in Venn diagram as we watch the following video: http://www.youtube.com/watch?v=9fxm85Fy4sQ

10. “I Can” Quiz - Respiration I Can Quiz: 1. Explain the function of the respiratory system 2. What are at least 5 organs found in the respiratory system? 3. What is the function of the alveoli? 4. Draw the path that air takes through the respiratory system.

11. Answers: 1. The respiratory system provides oxygen to the body and helps remove carbon dioxide 2. nasal cavity, pharynx, larynx, epiglotis, trachea, bronchi, bronchioles, alveoli, lungs, diaphram 3. alveoli are the site of gas exchange between the respiratory and circulatory systems 4.