Respiratory System

• Nose and mouth (nasal cavity)


  • Used to inhale and exhale air
  • The nose is what we normally use to inhale and exhale.
  • The nose has two holes called nostrils through which air passes.
  • The mouth is what we use to breathe when we need more air than what can be taken in through the nostrils.
• Pharynx


  • Also known as the throat
  • Where both food and air pass through
  • Lined with tissues called tonsils that contain white blood cells to attack disease-causing organisms
• Two phases of breathing

  1. Inspiration - the intake of air

  2. Expiration - the breathing out of air
• Cilia - little hairs that helps you filter the air you breathe in, blocking dirt and dust from getting into your lungs.
• Bronchioles - small tubes that branch off from bronchial tubes; they lead directly to the alveoli.
• Trachea - also known as the windpipe; it connects the larynx with the main bronchi, which carry air to the lungs.
• Lungs - two organs located on either side of the heart within the chest cavity; their primary function is to facilitate respiration by providing an area where gases can diffuse between the bloodstream and the atmosphere.
• Alveoli - tiny sacs where gas exchange occurs between blood and air
• Diaphragm - a large muscle that separates the thoracic cavity from the abdominal cavity. when inhaling, the diaphragm contracts; when exhaling, the diaphragm relaxes.
• Larynx - is also known as the "voicebox" because it houses the vocal chords and the different muscles used to produce sound.
• Epiglottis - flap-like structure at the back of the throat that covers the trachea during swallowing to prevent food particles from entering the airway.
• Diffusion - the process of gas exchange that takes place in the alveoli.
• Bronchus/Bronchi - the passage way that connects your windpipe to your lungs.
• Expiration - the process of breathing out, or exhalation.
• Inspiration - the process of breathing in, or inhalation.