UPPER
Functions of the Respiratory System
1. Gas exchanges between the blood and
external environment
– Occurs specifically in the alveoli of the lungs
2. Passageways to the lungs purify, humidify,
and warm the incoming air
1.
Organs of the Upper Respiratory
System
Nose
nasal cavity
paranasal sinuses
2. Pharynx
nasopharynx
oropharynx
laryngopharynx
3. Larynx
thyroid cartilage
epiglottis
vocal folds
glottis
4. Trachea
1. The Nose
• Only externally visible part of the respiratory
system
Basic Anatomy:
• External nostrils (nares)
• Interior of the nose
nasal cavity
nasal septum
Paranasal sinuses
Nasal Cavity
• Top of nasal cavity is the Cribriform plate
of the ethmoid bone contains openings
for olfactory nerves
• The nasal cavity is lined with respiratory
mucosa that
– Moisten air (humidify)
– Trap incoming foreign particles (purify)
• Lateral walls have projections called
conchae (remember the nasal conchae)
– Increase surface area
– Increase air movement within the
nasal cavity in order to increase
collection of foreign particles
Paranasal Sinuses
• Cavities within bones
that are surrounding
the nasal cavity and
share mucosa from
the nasal cavity are
called sinuses
• Sinuses are located in
the following bones
– Frontal bone
– Sphenoid bone
– Ethmoid bone
– Maxillary bone
Paranasal Sinuses
Function of the sinuses
– Lighten the skull
– Act as resonance chambers for speech
– Warms and moistens air
– Produce mucus that drains into the nasal
cavity
Sinuses are connected which is why a sinus
infection can cause secretion from the eyes
and ears
http://www.youtube.com/watch?v=ge5uUHmk2bE&NR=1
2. Pharynx (Throat)
• Muscular passage from nasal
cavity to larynx
• Three regions of the pharynx
1. Nasopharynx—superior
region behind nasal cavity
also connects to middle ear
2. Oropharynx—middle
region behind mouth,
carries air and food
3. Laryngopharynx—inferior
region attached to larynx,
carries air and food
https://www.youtube.com/watch?v=yQR8OWfLnMU
3. Larynx (voice box)
A. Thyroid cartilage
– Largest of the hyaline cartilages
– Protrudes anteriorly (Adam’s apple)
B. Epiglottis
– Routes food to the esophagus and air toward the
trachea
– When swallowing, the epiglottis rises and forms a
lid over the opening of the larynx
http://www.youtube.com/watch?v=Ri8bBhw9msQ
Structures of the Larynx (voice box)
C. Vocal folds (true vocal cords)
– Vibrate with expelled air to create sound
(speech)
D. Glottis —opening between vocal cords
Video of Vocal Cords
http://www.youtube.com/watch
?v=-XGds2GAvGQ
4. Trachea (Windpipe)
• Four-inch-long tube that connects larynx with
bronchi
• Walls are reinforced with C-shaped hyaline
cartilage (allows esophagus, which is behind the
trachea, the ability to expand for swallowing)
• Lined with ciliated mucosa
– Beat continuously in the opposite direction of incoming
air
– Expel mucus loaded with dust and other debris away
from lungs and into the esophagus