Respiratory System Anatomy

Respiratory System Anatomy

• The upper airway consists of the nose, oral cavity, and pharynx.
• Primary functions of upper airway include: conduction of air, filtering, speech, and smell.
• The nose is divided into two chambers by the nasal septum.
• The nasal septum is composed of the perpendicular plate of the ethmoid bone, vomer, septal cartilage, nasal bones, frontal process of the maxilla, cribriform plate of the ethmoid bone, and palatine process of the maxilla and palatine bones.
• The outer portion of the nose features nasal bones and frontal process of the maxilla (upper third or bridge), lateral nasal cartilage, greater alar cartilage, lesser alar cartilages, and fibrous fatty tissue (lower two thirds).
• The nose's internal portion features the nasal septum which separates the nasal cavity into two chambers.
• The nasal cavity's roof features nasal bones with the frontal process of the maxilla and cribriform plate of the ethmoid bone.
• The nasal cavity's floor contains the palatine process of the maxilla and palatine bones.
• The posterior portion of the nasal cavity is formed by the superior portion of the soft palate..
• Air conduction includes: nostrils (nares), vestibule with hair follicles (vibrissae - first line of defense of tracheobronchial tree), nasal passage (choanae), turbinates / conchae (bony protrusions on lateral nasal walls that increase surface area to warm, humidify & filter inspired gas).
• Paranasal sinuses are air-filled cavities in the skull that connect with the nasal cavity.
• Common paranasal sinuses include maxillary, frontal, ethmoid, and sphenoid sinuses.
• The purpose of paranasal sinuses is to provide mucus for lubrication in the nasal cavity, and also act as resonating chambers for producing sound.
• The oral cavity is an accessory respiratory passage.
• The oral cavity's roof is the hard palate, formed by the palatine process of the maxilla and palatine bones.
• The oral cavity's soft palate is a mass of collagen connecting with the uvula.
• The soft palate closes between nasal and oral cavities during swallowing or sucking/blowing.
• The oropharynx is located between the soft palate and the base of the tongue.
• The oropharynx contains the lingual tonsil at the root of the tongue.
• The laryngopharynx is located between the base of the tongue and the entrance to the esophagus.
• The epiglottis is anterior to the laryngopharynx.
• Intubation is a process used when needed to bypass the upper airway if there is excessive mucus secretions, partial or full obstruction. Air trapping (mucous plug) is also an indicator.