respi

• Respiration


  The exchange of gases between the atmosphere, blood, and cells
• Respiration


  1. Ventilation (breathing)

  2. External (pulmonary) respiration

  3. Internal (tissue) respiration
• Cardiovascular system


  • Assists the respiratory system by transporting gases
• Components of the respiratory system

  • Upper respiratory system
  • Lower respiratory system
• Conducting zone


  Consists of the nose, pharynx, larynx, trachea, bronchi, and bronchioles. Provides a route for incoming and outgoing air, removes debris and pathogens, warms and humidifies incoming air
• Respiratory zone


  Includes structures directly involved in gas exchange, such as respiratory bronchioles, alveolar ducts, and alveoli
• Upper respiratory system


  • Nose
  • Pharynx
  • Associated structures
• Lower respiratory system


  • Larynx
  • Trachea
  • Bronchi
  • Lungs
• Nose


  • External portion made of cartilage and skin, lined with mucus membrane
  • Bony framework formed by frontal, nasal, and maxillary bones
  • Functions to warm and humidify inspired air, remove and trap pathogens and particulate matter, provide sense of smell, drain and clear paranasal sinuses and lacrimal ducts
• Nasal conchae


  Curved shelves of bones projecting into the nasal cavity, creating pathways for air flow called meatuses. Increase surface area of nasal cavity and disrupt fast lamellar air flow to allow for humidification
• Nasal conchae


  • Inferior nasal concha
  • Middle nasal concha
  • Superior nasal concha
• Nasal meatuses


  • Inferior nasal meatus
  • Middle nasal meatus
  • Superior nasal meatus
• Pharynx


  • Muscular funnel-shaped passageway connecting mouth, nose, esophagus, and larynx
  • Functions as a passageway for air and food, provides a resonating chamber for speech, houses tonsils for immune function
• Regions of the pharynx

  • Nasopharynx
  • Oropharynx
  • Laryngopharynx
• Larynx


  Small structure of cartilage that connects the throat to the windpipe, houses the vocal cords that produce speech and contribute to respiration
• Cartilages of the larynx

  • Thyroid cartilage
  • Epiglottis
  • Cricoid cartilage
  • Arytenoid cartilage
  • Corniculate cartilage
  • Cuneiform cartilage
• Vocal folds (vocal cords)


  Two flaps of cartilage that vibrate to produce sound
• Glottis


  The opening between the two vocal folds, opens during breathing and closes during swallowing and sound production
• Voice production subsystems


  • Air pressure system
  • Vibratory system
  • Resonating system
• Functions of the larynx

  • Opens and closes the glottis
  • Role in breathing - glottis opens during breathing
  • Role in swallowing - glottis closes for food to enter esophagus
  • Role in voice - glottis closes and vocal fold tension adjusts
• Trachea


  Tube that extends from the larynx to the primary bronchi, allows air to pass from the upper respiratory tract to the lungs
• Trachea


  • Warms and moisturizes air before it enters the lungs
  • Traps particles in mucus lining to prevent entry into the lungs
• Bronchi


  Main airways into the lungs, responsible for protecting the lungs from infection and injury by trapping foreign particles in mucus
• Right lung has 3 lobes, left lung has 2 lobes
• Lungs


  Paired organs in the thoracic cavity that take in oxygen from the environment and transfer it to the bloodstream, and remove carbon dioxide from the bloodstream to be exhaled
• Alveoli


  Air sacs within the lungs where gas exchange occurs, with oxygen entering the bloodstream and carbon dioxide leaving
• Alveolar cells


  • Type I cells cover 90% of the alveolar surface and constitute the air-blood barrier
  • Type II cells produce surfactant to reduce surface tension and can differentiate into new alveolar cells after injury
• Movement of air through the respiratory system

  1. Inhale air through mouth or nose

  2. Air travels down trachea (windpipe)

  3. Air travels through bronchi

  4. Air enters lungs

  5. Air moves through bronchioles

  6. Air moves through alveolar ducts

  7. Air enters alveoli

  8. O2 moves from alveoli to bloodstream

  9. CO2 moves from bloodstream to alveoli

  10. CO2 is exhaled through mouth or nose
• Alveoli


  • Sac-like structures where gas exchange occurs
  • Composed of type I and type II alveolar cells
• Type I alveolar cells

  Cover 90% of alveolar surface, form air-blood barrier
• Type II alveolar cells


  Produce surfactant, can become stem cells to replace damaged alveolar cells
• Respiratory membrane


  Thin tissue barrier where gas exchange occurs, composed of alveolar cells, basement membranes, and capillary endothelium
• Blood supply to the lungs

  1. Blood enters via pulmonary arteries and bronchial arteries

  2. Blood exits via pulmonary veins and bronchial veins
• Hypoxia (low oxygen)


  Causes vasoconstriction in pulmonary arteries, diverts blood to better ventilated areas
• Long-term hypoxia


  Causes pulmonary vessels to constrict and become inelastic, overworks right side of heart
• Ventilation


  Movement of gas during breathing
• Perfusion


  Regulation of pulmonary blood flow to deliver oxygen
• Ventilation-perfusion coupling


  Relationship between ventilation and perfusion processes in the respiratory and cardiovascular systems
• Pulmonary ventilation (breathing)


  1. Inhalation - diaphragm contracts, lungs expand, air drawn in

  2. Exhalation - diaphragm relaxes, lungs made smaller, air expelled
• Boyle's Law


  Relationship between pressure and volume of a gas - as volume increases, pressure decreases