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• Respiratory system


  Structures used to acquire O2 and remove CO2 from the blood
• All cells in the body require O2 to synthesize the chemical energy molecule, ATP
• CO2 is a by-product of ATP production and must be removed from the blood
• Increased levels of CO2 will lower the pH of the blood
• External nose


  • Encloses the chamber for air inspiration
• Nasal cavity


  • A cleaning, warming, and humidifying chamber for inspired air
• Pharynx


  • Commonly called the throat, it serves as a shared passageway for food and air
• Larynx


  • The voice box
• Trachea


  • Commonly known as the windpipe. An air-cleaning tube to funnel inspired air to each lung
• Bronchi


  • Tubes that direct air into the lungs
• Lungs


  • Labyrinths of air tubes and a complex network of air sacs, called alveoli, and capillaries. Each air sac is the site of gas exchange between the air and the blood
• Upper respiratory tract


  • Structures from the nose to the larynx
• Lower respiratory tract


  • Structures from the trachea through the alveoli in the lungs
• Conducting zone


  • Structures from the nose to the air tubes within the lungs used strictly for ventilation
• Respiratory zone


  • Small air tubes in the lungs and the alveoli where gas exchange occurs
• Ventilation


  Breathing, the movement of air into and out of the lungs
• External Respiration


  The exchange of O2 and CO2 between the air in the lungs and the blood
• Gas Transport


  O2 and CO2 travel in the blood to and from cells
• Internal Respiration


  The exchange of O2 and CO2 between the blood and the tissues
• Regulation of blood pH


  • The respiratory system can alter blood pH by changing blood CO2 levels
• Production of chemical mediators


  • The lungs produce an enzyme called angiotensin-converting enzyme (ACE), which regulates blood pressure
• Voice production


  • Air moving past the vocal folds makes sound and speech possible
• Olfaction


  • The sensation of smell occurs when airborne molecules are drawn into the nasal cavity
• Protection


  • The respiratory system provides protection against some microorganisms by preventing them from entering the body and removing them from respiratory surfaces
• External nose


  • Composed mainly of hyaline cartilage
• Nasal cavity


  • Extends from nares (nostrils) to the choana which are the openings to pharynx
  • Hard palate is its roof
  • The nasal septum divides it in half
• Paranasal sinuses


  • Air filled spaces within bone
  • Open into nasal cavity
  • Lined with mucous
• Conchae


  • Bony projections on each side of nasal cavity
  • Increase surface area of nasal cavity
  • Help in cleaning, humidifying, warming of air
• Nasolacrimal ducts


  • Carry tears from eyes
  • Open into nasal cavity
• Serves as a passageway for air


  Remains open even when the mouth is full of food
• Cleans the air


  The nasal cavity is lined with hairs, which trap some of the large particles of dust in the air
• Humidifies and warms the air

  Moisture is added to the air as it passes through the nasal cavity
• Contains the olfactory epithelium

  • The sensory organ for smell, is located in the most superior part of the nasal cavity
• Helps determine voice sound

  The nasal cavity and paranasal sinuses are resonating chambers for speech
• Pharynx


  • A common passageway for the respiratory and digestive systems
  • Nasopharynx takes in air
  • Oropharynx extends from uvula to epiglottis and takes in food, drink, and air
  • Laryngopharynx extends from epiglottis to esophagus and food and drink pass through
• Uvula


  • "Little grape", extension of soft palate
• Pharyngeal tonsil


  • Aids in defending against infections
• Larynx


  • Located in the anterior throat and extends from the base of the tongue to the trachea
  • Consists of 9 cartilages
  • Thyroid cartilage is the largest piece of cartilage and is called the Adam's apple
• Epiglottis


  • Piece of cartilage that is a flap that prevents swallowed materials from entering larynx
• Vestibular folds


  • False vocal cords