Respiratory System

Functions

  • Provides the structures for the exchange of oxygen (O2) and carbon dioxide (CO2) in the body through respiration
  • Responsible for the production of sound
  • Breath in 21% oxygen and breath out about 17% oxygen
  • Produces the sound of your voice

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Respiration

  • The exchange between a living organism and its environment
  • The exchange occurs with O2 and CO2, a waste product for metabolism
  • Subdivisions
      * External
      * Internal
      * Cellular

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Upper Airway

  • Nasal cavity
  • Oral cavity
  • Pharynx
  • Larynx

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Nasal cavity

  • Air enters the respiratory system through the anterior nares (nostrils)
  • It travels through the nasal cavity which is divided by the nasal septum (partition)
      * Both are lined with mucous membranes
  • The air then strikes 3 bony projections called turbinates (nasal conchae bones)
  • Sinuses - cavities in the skull
      * Frontal
      * maxillary
      * Sphenoid
      * Ethmoid

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Oral Cavity

  • Includes the:
      * Cheeks
      * Hard and soft palates
      * Tongue
  • The hard palate separates the nasal cavity from the oral
  • The tongue is attached to the mandible and hyoid bone by muscles and ligaments.
  • Hyoid bone is U-shaped and located below the chin
      * Only bone in the axial skeleton does not articulate with any other bone.
  • It serves to anchor the tongue and larynx as well as support the trachea.

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The Pharynx: Throat

  • Muscular tube
  • Runs from soft palate to the superior portion of the esophagus
  • Approximately 5 inches long

Subdivided into:

  • Nasopharynx
      * Back of nasal opening to soft palate
      * Eustachian tubes open directly into nasopharynx
  • Oropharynx
      * Soft palate to behind the mouth (to hyoid bone)
  • Laryngopharynx (hypopharynx)
      * Located below the oropharynx and superior to the larynx
  • Epiglottis: leaf shaped flap of the cartilage behind the tongue that prevents food from entering the respiratory tract

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The Larynx (voice box)

  • Triangular chamber found below the pharynx
  • It joins the pharynx with the trachea
  • Lined with mucous membrane
  • 9 fibrocartilaginous plates
  • The largest is the thyroid cartilage (Adams Apple)
  • The cricoid cartilage is below the thyroid cartilage
  • The vocal cords are located behind the thyroid cartilage
  • The glottis is an opening in between the vocal cords
  • Air from the lung passes through the vocal cords creating sound

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The Lower Airway

The lower airway include:

  • Trachea
  • Bronchi
  • Alveoli
  • Lungs
  • Pleura

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The Trachea (wind pipe)

  • A tube like passage way, approximately 4.5”
  • Extends from the larynx and passes in front of the esophagus and continues to form a right and left mainstem bronchi
  • It has C-shaped cartilage that forms a frame