1. The Respiratory System 7SCIENCE

2. Why study the respiratory system? What do humans need to survive? Humans need many things to survive, one is food and the other is air We are ALWAYS breathing Breathing: – the process where fresh air moves into your lungs and stale air moves out of your lungs

3. Connected to the digestive system The digestive system prepares and stores energy from digested food in your cells Respiration: the process of releasing this energy through using oxygen – Oxygen is required to release the energy from cells Carbon dioxide (what we breathe out) is a waste product from this respiration

4. Main organs of the respiratory system Nasal cavity Pharynx Larynx Trachea Bronchi (Bronchioles) Lungs

5. Nasal Cavity, Pharynx, Larynx Nasal cavity: Air enters through your nose or mouth Pharynx – Tube that food and air pass through – Epiglottis: a flap of muscle that prevents food from entering the larynx Larynx – Airway that attaches to vocal cords As air passes over vocal cords, the muscles vibrate and tighten or loosen to make a sound (speaking!)

6. Trachea, Bronchi Trachea: – Below the larynx and is made of cartilage rings Bronchi: – At the end of the trachea are branches that carry air into the lungs – Split into smaller branches called bronchioles

7. Lungs, Alveoli Lungs: – Take up most of the space in the chest – Bronchi enter the lungs and split into bronchioles (smaller tubes) – At the end of these tubes are clusters of tiny sacs, called alveoli Alveoli – Exchange of oxygen and carbon dioxide – Happens easily because alveoli have walls that are one cell thick