CH 22 Upper Respiratory Anatomy

James F. Thompson, Ph.D.

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 Shape of the Nose Evolves in Response to the Environment

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

End CH 22: Upper Respiratory Anatomy