1. Structures of the Respiratory System
Nose, Pharynx, Larynx, Trachea
Pages
© 2015 Pearson Education, Inc.

2. Organs of the Respiratory System (in order from superior to inferior)
Nose
Pharynx
Larynx
Trachea
Bronchi
Lungs—alveoli
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3. Nasal cavity Oral cavity Nostril Pharynx Larynx Trachea Left main
Figure 13.1 The major respiratory organs shown in relation to surrounding structures.
Nasal cavity
Oral cavity
Nostril
Pharynx
Larynx
Trachea
Left main
(primary)
bronchus
Right main
(primary)
bronchus
Left lung
Right lung
Diaphragm

4. Functions of the Respiratory System
Air is inhaled… passageways function to:
Purify air
Humidify air
Warm air
Gas exchange occurs between:
blood & external environment
Occurs in the alveoli of the lungs
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5. The Nose The only externally visible part of the respiratory system
Air enters the nose through nostrils (nares)
Nasal septum divides the interior of the nose
Respiratory mucosa lines the cavity:
Traps bacteria/debris
Lysozymes destroy
Cilia sweeps posteriorly to throat
Swallowed and digested by stomach juices
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6. The Nose Lateral walls have conchae
Increase surface area
Increase air turbulence within the nasal cavity
Helps to trap debris/foreign substances
The nasal and oral cavities are separated by the palate
Anterior hard palate (bone)
Posterior soft palate (unsupported)
A cleft palate is when the palate bones fail to fuse medially
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7. Paranasal Sinuses Functions of sinuses: Lighten skull Resonate speech
Produce mucus
Squamous epithelial cells line the sinuses and secrete
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8. Nasal conchae (superior, middle and inferior) Nasopharynx
Figure 13.2b Basic anatomy of the upper respiratory tract, sagittal section.
Frontal sinus
Sphenoidal sinus
Nasal cavity
Nasal conchae (superior,
middle and inferior)
Nasopharynx
Pharyngeal tonsil
Nostril
Uvula
Hard palate
Oropharynx
Soft palate
Palatine tonsil
Tongue
Lingual tonsil
Hyoid bone
Laryngopharynx
Larynx
Epiglottis
Esophagus
Thyroid cartilage
Trachea
Vocal fold
Cricoid cartilage
(b)
Detailed anatomy of the upper respiratory tract

9. Pharynx (Throat) Muscular passage from nasal cavity to larynx
Three regions of the pharynx:
Nasopharynx—superior region behind nasal cavity
Oropharynx—middle region behind mouth
Laryngopharynx—inferior region attached to larynx
The oropharynx and laryngopharynx are common passageways for air and food
© 2015 Pearson Education, Inc.

10. Pharynx Nasopharynx Oropharynx Laryngopharynx (a)
Figure 13.2a Basic anatomy of the upper respiratory tract, sagittal section.
Pharynx
Nasopharynx
Oropharynx
Laryngopharynx
(a)
Regions of the pharynx

11. Tonsils Tonsils of the pharynx include:
Pharyngeal tonsil (adenoid) is located in the nasopharynx
Palatine tonsils are located in the oropharynx
Lingual tonsils are found at the base of the tongue
Tonsils are clusters of lymphatic tissue
Become inflamed/swollen from infection= tonsilitis
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12. Larynx (Voice Box) Allows us to speak:
glottis – structure that includes the vocal cords and their slitlike pathway (opening)
Vocal folds (true vocal cords) vibrate when air is expelled = speech
Multiple cartilages surround and protect the larynx
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13. Cartilages of Larynx
eight rigid hyaline cartilages and a spoon- shaped flap of elastic cartilage
Thyroid cartilage (Adam’s apple)
Largest of the hyaline cartilages
Epiglottis (elastic cartilage)
Closes superior opening of the larynx during swallow
Routes food to the esophagus and air toward the trachea

14. Cartilage of the larynx
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15. Trachea (Windpipe) 4-inch-long tube that connects larynx to bronchi
C-shaped hyaline cartilage reinforces walls
Protect by keeping trachea “open”
Allows esophagus to expand
Lined with ciliated mucosa
Cilia beat in the opposite direction of incoming air
Cilia expel mucus loaded with dust/debris away from lungs
© 2015 Pearson Education, Inc.

16. Figure 13.3a Structural relationship of the trachea and esophagus.
Posterior
Mucosa
Esophagus
Submucosa
Seromucous
gland in
submucosa
Trachealis
muscle
Lumen of
trachea
Hyaline
cartilage
Anterior
(a)

17. Figure 13.3b Structural relationship of the trachea and esophagus.
Cilia lining the trachea

18. Nasal conchae (superior, middle and inferior) Nasopharynx
Figure 13.2b Basic anatomy of the upper respiratory tract, sagittal section.
Frontal sinus
Sphenoidal sinus
Nasal cavity
Nasal conchae (superior,
middle and inferior)
Nasopharynx
Pharyngeal tonsil
Nostril
Uvula
Hard palate
Oropharynx
Soft palate
Palatine tonsil
Tongue
Lingual tonsil
Hyoid bone
Laryngopharynx
Larynx
Epiglottis
Esophagus
Thyroid cartilage
Trachea
Vocal fold
Cricoid cartilage
(b)
Detailed anatomy of the upper respiratory tract