Complex Pathway For Respiration• Specialized structures for: – conduction – gas exchange– position along the
respiratory pathway determines the cell type lining the airway
• Two anatomical and clinical subdivisions– upper respiratory
tract – lower respiratory
tract
The Nose and Nasal Cavity
• Anatomy– external nares– vestibule– nasal cavity and
septum– nasal conchae and
meatuses– paranasal sinuses
• Physiology– hairs filter air– mucosa warms and
humidifies air– mucus traps air
particles– olfactory epithelium
detect smell stimuli– entire structure serves
as resonating chamber for speech sounds
The Pharynx
• Anatomy– nasopharynx– oropharynx– laryngopharynx
• Physiology– the common
passage way for air and food
– guarded by tonsils
– not an intelligent design!
naso
oro
laryngo
The Larynx• Thyroid cartilage• Cricoid cartilage
• Epiglottis (“valve”)
• 3 smaller pairs of cartilage
• Cuneiform• Corniculate• Arytenoid
The Larynx
Voice Production
• Vestibular folds (false vocal cords)
• Vocal folds (true vocal cords)
– during exhalation laryngeal muscles pull the folds across the opening and tense the folds
– exhaled air induces vibrations which create sound waves
– volume– pitch
The Trachea• Anatomy
– mucosa, submucosa, hyaline cartilage, adventitia
– conduction portion of the airway has ciliated pseudostratified columnar epithelium w/ goblet cells
– cartilage “C” shaped rings• allow for support,
expansion, protection• trachealis muscle on
esophageal (dorsal) side
• Physiology– airway has same cleaning
defenses as nasal cavity, but also the mucociliary elevator
– we cough to clear the airway
The Bronchi• Carina
– Sensitive area– Cough reflex
• Entering lungs - primary bronchus secondary bronchi tertiary bronchi bronchioles terminal bronchioles
• Bronchi - R & L primary bronchi– R shorter, wider
more vertical
The Respiratory TreeExtends Into The Lungs
• Structural changes– Epithelium– Cartilage– Smooth muscle
• Parasympathetic (ANS), allergic response - bronchoconstriction
• Sympathetic (ANS) response - bronchodilation
• histamine release• allergy/asthma