Respiratory System Notes
22 Respiratory System
The Respiratory System
Respiratory System
Consists of the respiratory and conducting zones
Respiratory zone:
Site of gas exchange
Consists of bronchioles, alveolar ducts, and alveoli
Respiratory System
Conducting zone:
Conduits for air to reach the sites of gas exchange
Includes all other respiratory structures (e.g., nose, nasal cavity, pharynx, trachea)
Respiratory muscles – diaphragm and other muscles that promote ventilation
Major Functions of the Respiratory System
To supply the body with oxygen and dispose of carbon dioxide
Respiration – four distinct processes must happen
Pulmonary ventilation – moving air into and out of the lungs
External respiration – gas exchange between the lungs and the blood
Major Functions of the Respiratory System
Transport – transport of oxygen and carbon dioxide between the lungs and tissues
Internal respiration – gas exchange between systemic blood vessels and tissues
Function of the Nose
The only externally visible part of the respiratory system that functions by:
Providing an airway for respiration
Moistening and warming the entering air
Filtering inspired air and cleaning it of foreign matter
Serving as a resonating chamber for speech
Housing the olfactory receptors
Nasal Cavity
Vestibule – nasal cavity superior to the nares
Vibrissae – hairs that filter coarse particles from inspired air
Olfactory mucosa
Lines the superior nasal cavity
Contains smell receptors
Respiratory mucosa
Lines the balance of the nasal cavity
Glands secrete mucus containing lysozyme and defensins to help destroy bacteria
Pharynx
Funnel-shaped tube of skeletal muscle that connects to the:
Nasal cavity and mouth superiorly
Larynx and esophagus inferiorly
Extends from the base of the skull to the level of the sixth cervical vertebra
Pharynx
It is divided into three regions
Nasopharynx
Oropharynx
Laryngopharynx
Larynx (Voice Box)
Attaches to the hyoid bone and opens into the
The Respiratory System
Respiratory System
Consists of the respiratory and conducting zones
Respiratory zone:
Site of gas exchange
Consists of bronchioles, alveolar ducts, and alveoli
Respiratory System
Conducting zone:
Conduits for air to reach the sites of gas exchange
Includes all other respiratory structures (e.g., nose, nasal cavity, pharynx, trachea)
Respiratory muscles – diaphragm and other muscles that promote ventilation
Major Functions of the Respiratory System
To supply the body with oxygen and dispose of carbon dioxide
Respiration – four distinct processes must happen
Pulmonary ventilation – moving air into and out of the lungs
External respiration – gas exchange between the lungs and the blood
Major Functions of the Respiratory System
Transport – transport of oxygen and carbon dioxide between the lungs and tissues
Internal respiration – gas exchange between systemic blood vessels and tissues
Function of the Nose
The only externally visible part of the respiratory system that functions by:
Providing an airway for respiration
Moistening and warming the entering air
Filtering inspired air and cleaning it of foreign matter
Serving as a resonating chamber for speech
Housing the olfactory receptors
Nasal Cavity
Vestibule – nasal cavity superior to the nares
Vibrissae – hairs that filter coarse particles from inspired air
Olfactory mucosa
Lines the superior nasal cavity
Contains smell receptors
Respiratory mucosa
Lines the balance of the nasal cavity
Glands secrete mucus containing lysozyme and defensins to help destroy bacteria
Pharynx
Funnel-shaped tube of skeletal muscle that connects to the:
Nasal cavity and mouth superiorly
Larynx and esophagus inferiorly
Extends from the base of the skull to the level of the sixth cervical vertebra
Pharynx
It is divided into three regions
Nasopharynx
Oropharynx
Laryngopharynx
Larynx (Voice Box)
Attaches to the hyoid bone and opens into the