respiratory

• Respiration


  1. Pulmonary ventilation (inhalation and exhalation of air)

  2. External (pulmonary) respiration (exchange of gases between alveoli and blood)

  3. Internal (tissue) respiration (exchange of gases between blood and tissue cells)
• Respiratory system


  Consists of the nose, pharynx, larynx, trachea, bronchi, and lungs

  
• Parts of the respiratory system

  • Upper respiratory system (nose, nasal cavity, pharynx)
  • Lower respiratory system (larynx, trachea, bronchi, lungs)

  
• Functional parts of the respiratory system

  • Conducting zone (nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles)
  • Respiratory zone (respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli)

  
• Otorhinolaryngology


  Branch of medicine that deals with the diagnosis and treatment of diseases of the ears, nose, and throat

  
• Nose


  • Consists of external nose and internal nasal cavity
  • Warms, moistens, and filters incoming air
  • Detects olfactory stimuli
  • Modifies speech vibrations
• Nasal cavity


  • Large space in the anterior aspect of the skull, lined with muscle and mucous membrane
  • Divided into right and left sides by the nasal septum
  • Communicates with the pharynx through the internal nares or choanae

  
• Paranasal sinuses


  • Frontal
  • Sphenoid
  • Ethmoid
  • Maxillary
• The bony and cartilaginous framework of the nose help to keep the vestibule and nasal cavity patent (open or unobstructed)
• The nasal cavity is divided into a larger, inferior respiratory region and a smaller, superior olfactory region
• The respiratory region is lined with ciliated pseudostratified columnar epithelium with numerous goblet cells that secrete mucus

  
• The olfactory region is located in the superior part of the nasal cavity and is lined with olfactory epithelium containing olfactory receptor cells
• Nasopharynx


  The superior portion of the pharynx, posterior to the nasal cavity and extending to the soft palate
• Oropharynx


  The intermediate portion of the pharynx, posterior to the oral cavity and extending from the soft palate to the level of the hyoid bone
• The nasopharynx receives air from the nasal cavity along with packages of dust-laden mucus, and the cilia move the mucus down toward the most inferior part of the pharynx
• The nasopharynx also exchanges small amounts of air with the auditory tubes to equalize air pressure between the middle ear and the atmosphere
• The oropharynx serves as a common passageway for both the respiratory and digestive systems
• Nasopharynx


  Portion of the pharynx that receives air from the nasal cavity and is lined with ciliated pseudostratified columnar epithelium
• Oropharynx


  Portion of the pharynx that lies posterior to the oral cavity and serves as a common passageway for air, food, and drink
• Laryngopharynx (hypopharynx)


  Inferior portion of the pharynx that opens into the esophagus posteriorly and the larynx anteriorly
• Pharynx


  • Funnel-shaped tube about 13 cm long that starts at the internal nares and extends to the level of the cricoid cartilage
  • Wall is composed of skeletal muscles and lined with a mucous membrane
  • Relaxed skeletal muscles help keep the pharynx patent
  • Contraction of the skeletal muscles assists in swallowing
• Larynx (voice box)


  Short passageway that connects the laryngopharynx with the trachea
• Cartilages of the larynx

  • Thyroid cartilage
  • Epiglottis
  • Cricoid cartilage
  • Arytenoid cartilages
  • Cuneiform cartilages
  • Corniculate cartilages
• Thyroid cartilage


  Consists of two fused plates of hyaline cartilage that form the anterior wall of the larynx
• Epiglottis


  Large, leaf-shaped piece of elastic cartilage that moves up and down to close off the larynx during swallowing
• Cricoid cartilage


  Ring of hyaline cartilage that forms the inferior wall of the larynx
• Arytenoid cartilages


  Triangular pieces of mostly hyaline cartilage located at the posterior, superior border of the cricoid cartilage
• Corniculate cartilages


  Horn-shaped pieces of elastic cartilage located at the apex of each arytenoid cartilage
• Cuneiform cartilages


  Club-shaped elastic cartilages anterior to the corniculate cartilages that support the vocal folds and lateral aspects of the epiglottis
• Vocal folds (true vocal cords)

  Principal structures of voice production, consisting of bands of elastic ligaments stretched between the rigid cartilages of the larynx
• Vestibular folds (false vocal cords)


  Superior pair of folds in the larynx that do not function in voice production but help hold the breath against pressure in the thoracic cavity
• Rima glottidis


  Space between the vocal folds
• Laryngeal ventricle


  Lateral expansion of the middle portion of the laryngeal cavity inferior to the vestibular folds and superior to the vocal folds
• Voice production


  1. Intrinsic muscles contract to move the cartilages, which pulls the elastic ligaments tight and stretches the vocal folds

  2. Air passing through the larynx vibrates the vocal folds, producing sound waves
• Vocal fold tension


  Determines pitch of the sound produced
• Glottis


  Consists of a pair of folds of mucous membrane in the larynx (the vocal folds) and the space between them (the rima glottidis)
• Movement of the vocal folds

  1. Abduction (movement apart)

  2. Adduction (movement together)
• Vocal folds


  • Tension on the vocal folds controls pitch
  • Thicker and longer in males, vibrate more slowly, resulting in lower pitch range
• Sound production


  • Originates from the vibration of the vocal folds
  • Other structures (pharynx, mouth, nasal cavity, paranasal sinuses) act as resonating chambers to give voice its human and individual quality
• Whispering


  • Accomplished by closing all but the posterior portion of the rima glottidis
  • No vibration of vocal folds, so no pitch, but can still produce intelligible speech by changing the shape of the oral cavity