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
Organs of the Upper Respiratory System1. Nose
nasal cavityparasinuses
2. Pharynxnasopharynxoropharynxlaryngopharynx
3. Larynxthyroid cartilageepiglottisvocal foldsglottis
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 septumparasinuses
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 SinusesFunction 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
http://www.youtube.com/watch?v=HJHYTz14CkY&NR=1
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 Cordshttp://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