Lesson 1, Topic 1
In Progress

Anatomy of the Upper Respiratory Tract

April 11, 2024

Learning Objective: Differentiate among the structures of the upper respiratory tract.
      The upper respiratory tract is composed of structures from the nose to the larynx. These organs are located outside the chest cavity. The upper respiratory tract has several functions:
             • Warming and cleaning the inspired air
             • Serving as a passageway for air
             • Providing the sense of smell


Nose and Paranasal Sinuses
Learning Objective: Discuss the anatomy of the nose and paranasal sinuses.
      Air can enter through the mouth or the two nares (nostrils) in the nose. The nasal septum separates the nares. The air then moves into the nasal cavity. The surface capillaries, mucous membrane, and cilia (small hairs) found in the nasal cavity clean, warm, and moisten the air. The cilia continually move in a wavelike motion to push mucus and debris out of the respiratory tract. Receptors for smell are in the nasal cavity. The nasal cavity is connected to four pairs of paranasal sinuses . The four pairs of paranasal sinuses are named for the bones they are found in: maxillary, frontal, sphenoid, and ethmoid.


Pharynx
Learning Objective: Describe the anatomy of the pharynx.
      Air continues to travel into the pharynx (throat) (FIGURE 26.1), which is divided into three sections:
             • Nasopharynx: Located behind the nasal cavity. The eustachian tube connects the middle ear to the nasopharynx and equalizes the pressure in the ear with the air pressure outside the body.
             • Oropharynx: Located behind the mouth and part of the respiratory and digestive systems.
             • Laryngopharynx: Located between the epiglottis and the esophagus. The epiglottis, a flap of cartilage at the larynx opening, closes off the trachea when food is swallowed. As air passes out through the opening, the larynx (vocal cords) vibrates to produce speech. The vocal cords are paired bands of cartilaginous tissue.


26.1 Critical Thinking Application
Describe the structures that make up the upper respiratory tract.