24.1 Overview of Respiratory System and Respiratory Tract

• • The respiratory system includes all structures from the nose to the alveoli. The respiratory system is divided into upper and lower respiratory systems.
• The respiratory system consists of the nose, nasal cavity and paranasal sinus, pharynx, larynx, tracha, and smaller conducting passageways to the alveoli
• Alveoli are the gas exchange surfaces within the lungs
• The upper respiratory system consists of the paranasal sinuses, nasal conchae, nose, and nasal cavity, and nasopharynx
• The lower respiratory system includes the larynx, trachea, bronchi, lungs, bronchioles, and alveoli of the lungs
• The respiratory tract consists of a conducting portion, which extends from the entrance to the nasal cavity to the bronchioles, and a respiratory portion which includes the respiratory bronchioles and the alveoli
• List the main functions of the respiratory system.

  The main functions of the respiratory system include providing an extensive area for gas exchange between air and circulating blood; moving air to and from the exchange surfaces of the lungs; protecting respiratory surfaces from dehydration, temperature changes, and other environmental variations; defending the respiratory system from pathogens; producing sounds involved in speaking; and helping regulate blood volume, blood pressure, and the control of body fluid pH.
• What is the mucociliary escalator?

  The mucociliary escalator is present in the lower regions of the respiratory tract, where the cilia of the respiratory epithelium beat toward the pharynx, cleaning the respiratory passageways.
• SUMMARY

  • Respiratory system includes nose, nasal cavity, sinuses, pharynx, larynx, trachea, conducting passageways leading to exchange surfaces of lungs.
  • Upper respiratory system consists of paranasal sinuses, nasal conchae, nose, nasal cavity, nasopharynx. These begin process of filtration and humidification of incoming air. Lower respiratory system includes trachea, lungs, bronchi, bronchioles, alveoli of lungs.
  • Respiratory tract consists of conducting portion, extends from entrances to nasal cavity to bronchioles, and respiratory portion, includes respiratory bronchioles and alveoli.
• SUMMARY - Functions of the Respiratory System

  • The respiratory system provides an area for gas exchange between air and circulating blood, moves air to and from exchange surfaces, protects respiratory surfaces, defends the respiratory system and other tissues from pathogens, permits vocal communication, and helps regulate blood volume and pressure and body fluid pH.
• SUMMARY - The Respiratory Epithelium

  • Respiratory epithelium lines conducting portions of respiratory system down to level of terminal bronchioles.
  • Respiratory epithelium consists of pseudostratified ciliated columnar epithelium with mucous cells.
  • Respiratory epithelium produces mucus traps incoming particles. Underneath is lamina propria (layer of connective tissue); combined respiratory epithelium and lamina propria form mucosa (mucus membrane).
  • Respiratory defense system includes mucous glands and mucus produced (washes particles toward the stomach), alveolar macrophages, hairs, cilia.