The Pharynx and Larynx Flashcards
Function of Pharynx
-Shared passageway for both air and food
-Provides a resonating chamber for speech sounds
-Houses tonsils, which serve immunological functions
*extends from choanae (internal nares) to C6
Divisions of Pharynx (3)
- Nasopharynx (superior portion)
- Oropharynx (middle portion)
- Laryngopharynx (inferior portion)
Nasopharynx Borders
Superior: Choanae
Posterior: Vertebral bodies
Anterior/Inferior: Soft palate and Oropharynx
*Respiratory function
Key features:
-Soft palate
-Openings to eustachian tube
-Adenoid (pharyngeal tonsil)
Soft Palate
Forms posterior roof of mouth (continuous with hard palate)
-Arch shaped muscular partition b/t nasopharynx and oropharynx
*contracts to close the nasopharynx when swallowing
“Don’t eat and talk”
Eustachian Tube
-Narrow passage between the nasopharynx and middle ear
-Allows air exchange to equalize pressure between these areas
Adenoid
-Patch of lymphoid tissue on the superior posterior wall
-Typically atrophies and shrinks significantly by adulthood
‘Pharyngeal tonsil’
Oropharynx Borders
Superior: Nasopharynx
Inferior: Laryngopharynx
Posterior: Vertebral bodies
Anterior: Fauces (throat)/oral cavity
*Respiratory and digestive functions
Key Features:
-Palatine tonsils
-Lingual tonsils
Oropharyngeal Tonsils
Patches of lymphoid tissue
-Lingual tonsils
-Palatine tonsils
Laryngopharynx Borders
Superior: Oropharynx
Inferior: Larynx and esophagus
Posterior: Vertebral bodies
*Respiratory and digestive functions
Key Features:
-Laryngeal inlet
-Piriform fossae (recesses)
Laryngopharynx Features
Laryngeal inlet: entrance to the larynx
Piriform fossa (recess): groove on either side of the laryngeal inlet
Pharynx Epithelium
Nasopharynx:
-Pseudostratified ciliated columnar epithelium (respiratory epithelium)
Oropharynx and Laryngopharynx:
-Nonkeratinized stratified squamous epithelium
Pharyngeal Muscles (3)
Outer Circular Layer:
1. Superior Constrictor (4)
2. Middle Constrictor (2)
3. Inferior Constrictor (2)
Superior Constrictor
Location: surrounds the oropharynx
Function: constricts the upper portion of the pharynx to facilitate swallowing
*4 fibres/attachments
Middle Constrictor
Location: surrounds the laryngopharynx
Function: constricts the middle portion of the pharynx to facilitate swallowing
*2 fibres/attachments
Inferior Constrictor
Location: surrounds the laryngopharynx
Function: constricts the lower portion of the pharynx to facilitate swallowing
-forms the upper esophageal sphincter
*2 fibres/attachments
Pharyngeal Muscle Attachments
Occipital bone- superior constrictor
Pharyngeal raphe- superior, middle and inferior
‘Raphe’= groove or ridge
Deep View to Superior Constrictor
Deep to superior constrictor, visible in posterior view= nasal conchae and nasal septum
Innervation of Pharyngeal Muscles
Motor: CN X (vagus)
Sensory: CN IX (glossopharyngeal)
Clinical Connection: Obstructive Sleep Apnea
Repetitive collapse/closure of pharynx during sleep, many etiologies including anatomical variations of pharynx
Uvulopalatopharyngoplasty (UPPP)= surgery to fix
Larynx
-Short passageway that connects the laryngopharynx with the trachea
-Anterior to C4-C7
Function:
-Valve to close trachea
-Voice production (via vocal cords)
Structure of Larynx
Consists of cartilage structure: *superior to inferior
- Epiglottis (single)
- Thyroid cartilage (single)
- Arytenoid cartilage (pair)
- Cricoid cartilage (single)
Superior= hyoid bone
Inferior= trachea
Epiglottis
-Leaf shaped piece of elastic cartilage
-Covered with epithelium
-“Stalk” is attached to thyroid cartilage
-“Leaf” is unattached
Function:
-Closes off larynx when swallowing (moves down and forms a lid over opening to larynx)
Thyroid Cartilage
-Largest cartilage of larynx
-Form upper and anterior walls
-2 fused plates of hyaline cartilage
Function:
Protect and support the vocal cords
*Laryngeal prominence= Adam’s Apple
Cricoid Cartilage
-Ring of hyaline cartilage
-Forms inferior wall of larynx
Function:
-Maintains airway opening
*Landmark for making an emergency airway
Arytenoid Cartilage
-Triangular pieces of mostly hyaline cartilage
-Sit on cricoid cartilage
Function:
-Influence movement (tension and relaxation) of vocal folds
Laryngeal Ligaments (3)
Support the cartilaginous skeleton of larynx
Extrinsic- attach larynx to external structures
1. Thyrohyoid membrane (medial and lateral thyrohyoid ligaments)
2. Cricotracheal ligament
Intrinsic- attach cartilages within the larynx
1. Cricothyroid ligament
True and False Vocal Cords
Mucous membrane of larynx forms 2 pairs of folds:
Superior= vestibular folds (“false” vocal cords)
-Protects the vocal folds
Inferior= vocal folds
(“true” vocal cords)
-Principle structure of voice production
Cavity of Larynx (5 Components)
- Vestibule- from inlet to vestibular folds (“false cords”)
- Glottis- from vestibular folds to vocal folds (“true cords”)
- Rima glottidis- gap between vocal folds, opening to infraglottic cavity
- Infraglottic cavity (space)- below vocal folds
- Trachea
Action of Vocal Cords
Intrinsic laryngeal muscles attach to cartilages and vocal folds
During respiration: abduct/open (allows for passage of air)
During swallowing:
adduct/close (to prevent food/liquid from entering)
During phonation: adduct and alter tension of vocal cords
Clinical Connection: Hiccups
Hiccups are caused from the diaphragm spasming, which closes the glottis and decreases air flow
Vocal Resonance
Larynx and pharynx are resonating chambers for speech
Reverberation of sound waves from vibrating vocal folds resonate in chambers and produce sound
Intrinsic Laryngeal Muscles
Act on individual components of larynx
-Control shape of rima glottidis
-Control length and tension of vocal folds
- Cricothyroid
- Thyroarytenoid
- Posterior and lateral cricoarytenoid
- Transverse and oblique arytenoid
Cricothyroid Muscle
Functions to stretch and tense vocal ligament
Known as “singers muscle” as it alters tone of voice
Thyroarytenoid Muscle
Functions to relax vocal ligament
Posterior and Lateral Cricoarytenoid
Posterior: functions as sole ABDUCTOR of vocal folds (widens rima glottidis/pulls apart)
Lateral: functions as major ADDUCTOR of vocal folds (narrows rima glottidis/pulls together)
Transverse and Oblique Arytenoid
Functions to adduct arytenoid cartilage, narrows rima glottidis to modulate tone and volume of speech
Oblique= crosses
Transverse= straight
Innervation of Larynx
- Superior Laryngeal Nerve:
a) Internal laryngeal nerve-> Sensory -> Above vocal cords
b) External laryngeal nerve-> Motor-> Cricothyroid - Recurrent Laryngeal Nerve
a) Sensory= below vocal cords
b) Motor= all except cricothyroid
