Pharynx and Larynx Flashcards
Pharynx
“U-shaped” musculomembranous structure located posterior to nasal cavity, oral cavity and larynx
Extends from base of skull –> C6
Pharynx joins nasal and oral cavities to
larynx and esophagus
Nasopharynx
pathway for air
Oropharynx
pathway for air and food/liquids
Air passes from..
oropharynx –> larynx –> trachea –> primary bronchi –> lungs
Food/liquid passes from oropharynx –>
laryngopharynx (pathway for food only), continuous with esophagus
Nasopharynx
continuous with nasal cavity
Extends from base of skull -> soft palate (marked by palatoglossal arch)
Torus tuberous (lateral)
- opening of pharyngo-tympanic tube (auditory tube)
- communication between nasopharynx and middle ear cavity
- salpingopharyngeus and elevator veil palatine assist in opening pharyngotympanic tube
Pharyngeal recess
posterior to torus tuberous; location of pharyngeal tonsils (enlargement - adenoids may interfere with nasal breathing)
Oropharynx
posterior to oral cavity
Extends from soft palate (palatoglossal arch) to superior border of epiglottis (c3)
Laryngopharynx
posterior to larynx
-Extends from superior border of epiglottis (C3) to inferior border of cricoid cartilage (C6)
communicates with larynx via laryngeal inlet on its anterior wall
Pharynx muscles Types
Circular and longitudinally oriented SKELETAL muscle
circular: superior, middle, inferior pharyngeal costrictors
longitudinal directed muscles: stylopharyngeus, palatopharyngeus, salpingopharyngeus
Superior pharyngeal constrictor
Attachments:
pharyngeal tubercle and pharyngeal raphe (posterior) –> pterygoid hamulus, pterygomandibular raphe and mandible
Innervation: CN-X via pharyngeal plexus
Middle pharyngeal constrictor
Attachments: pharyngeal raphe (posterior) –> stylohyoid ligament and hyoid bone
Innervation: CNX via pharyngeal plexus
Inferior pharyngeal constrictor
Attachments: pharyngeal raphe (posterior) –> thyroid cartilage and cricoid cartilage
Innervation: CNX via pharyngeal plexus, recurrent laryngeal n and external laryngeal nerve
Action of all 3 pharyngeal constrictors
Constricts wall of pharynx during swallowing
Superior to superior constrictor opening
Passage of pharyngotympanic tube, levator veli palatini and ascending palatine a (Branch of facial a)
Opening between superior and middle constrictors
passage of stylopharyngeus and CN 9
Opening between middle and inferior constrictors
passage of internal laryngeal nerve and superior laryngeal vessels
Inferior to inferior constrictor
passage of recurrent laryngeal nerve and inferior laryngeal artery (branch of inferior thyroid a)
Stylopharyngeus
Attachment: styloid process –> muscular wall of pharynx and thyroid cartilage
Innervation: CN-9
Palatopharyngeus
Attachments: posterior hard palate and palatine aponeurosis –> muscular wall of pharynx and thyroid cartilage
Innervation: CNX via pharyngeal plexus
Salpingopharyngeus
Attachment: cartilaginous part pharyngotympanic tube –> muscular wall of pharynx
Innervation: CNX via pharyngeal plexus
action of 3 longitudinal pharyngeal muscles
Elevate and WIDEN pharynx during swallowing
Noncontractile membranes/fascia of pharynx
non-contractile tissue “seals off” spaces so air, liquid and food do not “leak” from pharynx
- fascia lines internal and external surface of pharyngeal muscles
Pharyngobasilar fascia
Internal fascial lining of pharynx
- extends superior to superior constrictor, where it’s thickened
Superior attaches to occipital bone, petrous temporal bone, cartilaginous portion of pharyngotympanic tube and medial pterygoid plate –> thins inferiorly as it lines constrictor muscles
Buccopharyngeal fascia
external fascial lining of pharynx
Deglutition (swallowing)
transfer of bolus: oral cavity -> pharynx -> esophagus -> stomach
- ORAL PHASE (voluntary): tongue compresses bolus against hard-> soft palate
- PHARYNGEAL PHASE (involuntary)
- bolus enters oropharynx and soft palate tensed/elevated (Via tensor veli palatini and levator veli palatini), blocks communication between nasal and oral cavities
- - pharynx elevates, which brings laryngophrynx toward descending bolus
- –Contraction of pharyngeal constrictors propel bolus inferiorly to esophagus
- —Airway must be protected - ESOPHAGEAL PHASE (involuntary)
contraction propels bolus to esophagus-> stomach
Innervation of Pharynx
- Sensory and motor innervation - pharyngeal plexus (CN9 and 10)
- Sensory fibers from CN9. sensory info from mucous membrane of nasopharynx, oropharynx and laryngopharynx. (mucosa of nasopharynx also receives sensory fibers from pharyngeal branch of V2 - from PPG)
- Motor fibers from CN-10 - supply all muscles of pharynx EXCEPT stylopharyngeus (9)
- -inferior pharyngeal constrictor also receives motor fibers from recurrent and external laryngeal nerves
Larynx
- Located in anterior neck (anterior to pharynx)
- Cartilages, membranes, ligaments and moved by several muscles
- Necessary for voice production
-Guards airway
AT REST, anterior to C3-C6 vertebra (superior extension of epiglottis to inferior margin of cricoid cartilage)
Laryngeal skeleton 9 cartilages
3 unpaired:
- Epiglottis
- Thyroid
- Cricoid
3 paired
- arytenoid
- corniculate
- cuneiform
Thyroid cartilage
Largest, formed by 2 laminae that fuse in midline
Laryngeal prominence: prominent region on external surface of thyroid cartilage, where 2 laminae fuse
Angle of thyroid cartilage: angle (internal surface) resulting from fusion of 2 laminae
Posteriorly, extending from each lamina = 2 processes, superior horn and inferior horn
- – inferior horn has articular facet for cricoid cartilage
- -C4-C5 vertebral level
Epiglottic cartilage
superior end: free, C3
Inferior end: connected to angle of thyroid cartilage via thyroepiglottic ligament
-Bends to cover airway during swallowing
Cricoid cartilage
Most inferior of laryngeal cartilages (C6)
- Shaped like a signet ring, broad lamina positioned posteriorly and narrow arch positioned anteriorly
- Completely encircles airway
- Has articular surfaces for inferior horn of thyroid and arytenoid cartilages
Arytenoid cartilages
Pyramidal-shaped
Apex- articulates with corniculate cartilage
Base - articulates with lamina of cricoid cartilage
-Vocal process - projects anteriorly; attachment site for a ligament (vocal ligament) and muscle (vocals)
-Muscular process - projects laterally; attachment site for several muscles
Corniculate cartilages
articulate with apex of arytenoid cartilages
extend into aryepiglottic fold
Cuneiform cartilages
Located in aryepiglottic fold and provides stability to the fold
Joints of larynx
Cricothyroid joints: synovial joints between inferior horn of thyroid cartilage and cricoid cartilage
Cricoarytenoid joint
Synovial joints between arytenoid and cricoid cartilages
Arytenocorniculate joints
synovial joint or synchondrosis between arytenoid and corniculate cartilages
Extrinsic Membranes and Ligaments
- Thyrohyoid membrane: extends from thyroid cartilage to hyoid bone
- –Median thyrohyoid ligament: thick median aspect of thyrohyoid membrane
- —Lateral thyrohyoid ligament: thick posterior portion of thyrohyoid membrane
Cricotracheal ligament
Extrinsic
Extends from cricoid cartilage to 1st tracheal cartilage
Quadrangular membrane
Intrinsic
Drapes downward from epiglottis -> arytenoid cartilage
- -Aryepiglottic ligament: free superior margin of quadrangular membrane
- -Vestibular ligament - free inferior margin of quadrangular membrane
Cricothyroid ligament
intrinsic
Extends from cricoid cartilage to thyroid cartilage and arytenoid cartilage
- Vocal ligament : free superior margin of cricothyroid ligament
Intrinsic ligaments covered by mucous membrane
- Aryepiglottic fold
- aryepiglottic ligament, when covered by mucous membrane, forms aryepiglottic fold
NOTE: corniculate and cuneiform cartilages located in aryepiglotic fold
- vestibular fold, vocal fold
Vestibular Fold
Vestibular ligament when covered by mucous membrane forms vestibular folds
FALSE vocal cords
RIMA vestibuli: opening between vestibular folds
Vocal Fold
Vocal ligament, when covered by mucous membrane, forms vocal folds
TRUE vocal cords
Rima GLOTTIDIS: opening between vocal folds
Laryngeal inlet
opening between larynx and pharynx
Piriform recess
Depression on either side of laryngeal inlet
Laryngeal cavity
extends from laryngeal inlet -> continuous with trachea includes:
1. Supraglottic cavity (vestibule): between laryngeal inlet and vestibular folds
- Middle laryngeal cavity: region between vestibular folds and vocal folds
- –Laryngeal ventricle: extends laterally from middle laryngeal cavity
- –Laryngeal saccule: elongated tubular extension of ventricle; numerous mucous glands, which assist in lubricating vocal folds - Infraglottic cavity: between vocal folds and inferior border of cricoid cartilage (continuous with trachea)
Extrinsic laryngeal muscles
connect larynx to neighboring structures to move larynx
- Infrahyoids depress hyoid and larynx (EXCEPT thyrohyoid muscle elevates larynx)
- Suprahyoid elevate hyoid and larynx
Intrinsic laryngeal muscles
Move specific laryngeal cartilage, altering length and position of vocal ligaments and size/shape of rima glottidis
- Crycothyroid
- Posterior cricoarytenoid
- Lateral cricoarytenoid
- Transverse and oblique arytenoids
- Aryepiglotticus
- Vocalis
- Thyroarytenoids
- Thyroepiglotticus
Cricothyroid Muscle
Attachments:
- Cricoid arch
- Thyroid cartilage
Action
- Tilts thyroid cartilage anteriorly and inferiorly on cricoid, thereby lengthening vocal ligaments
Innervation: external branch of superior laryngeal nerve
Posterior cricoarytenoid muscle
Attachments:
- Cricoid lamina (posterior)
- Muscular process of arytenoid cartilage
Action:
ABducts vocal folds/open rima glottidis
note: only muscle to OPEN rima glottidis
Pull arytenoids posteriorly, assisting cricothyroid muscles in tensing vocal cords
Innervation: recurrent laryngeal nerve
Lateral cricoarytenoid muscle
Attachment:
- Cricoid arch (lateral)
- Muscular process of arytenoid cartilage
Action
1. Close rima glottidis
Innervation - recurrent laryngeal n
Transverse and Oblique Arytenoid Muscles and Aryepiglottic Muscle
Attachments
- Arytenoid muscle: from one arytenoid cartilage to contralateral arytenoid cartilage
- Aryepiglottic Muscle: formed by oblique arytenoid fibers that continue into aryepiglottic fold
Action: adduct arytenoid cartilages, closing posterior rima glottidis
Innervation: recurrent laryngeal n
Vocalis
Intrinsic Attachments: artyenoid cartilage (vocal process) angle of thyroid cartilage and along vocal ligament (thyroarytenoid internus muscle)
Action: produces minute adjustments of vocal ligaments; contraction produces localized relaxation of vocal ligament
Inn: recurrent laryngeal n
Thyroarytenoid muscles
Attachments:
- Arytenoid cartilage
- Angle of thyroid cartilage and along cricothyroid ligament
Action:
-Draw arytenoid cartilages toward thyroid cartilage, thereby relaxing vocal ligaments
Inn: recurrent laryngeal n
Phonation
Males have longer/thicker vocal ligaments
Inhalation-> vocal folds aBduct
prior to speaking -> vocal folds approximate –> increased pressure from below (subglottic pressure)
-Air from subglottic space moves through glottidis, causes vibration of vocal folds -> frequency of vibration related to sounds we hear
Pitch of one’s voice
Determined by length/tension relationship of vocal ligaments
- Increase tension in vocal ligaments-> increase vibration of vocal ligaments as air passes through larynx -> high pitch
- Decrease tension in vocal ligaments -> decrease vibration of vocal ligaments as air passes larynx -> low pitch
Phonation continued
Volume of sound depends upon force of air passing through vocal folds
- lot of air forced through rima glottidis -> loud
- little-soft
whispering= only posterior part of rima glottidis open, vocal folds DO NOT VIBRATE. all whispers have same pitch
-although vocal folds produce sound, pharynx, oral cavity, tongue and lips that use sounds to produce words
Deglutition (protecting airway)
larynx ELEVATEs, moves anteriorly
As movement occurs, epiglottis approximates the base of tongue, causing epiglottis to bend posteriorly, covering laryngeal inlet (aryepiglottic muscles may also assist in closing laryngeal inlet)
–bolus slips over anterior surface of epiglottis before passing laterally into piriform recess (lateral food passageway) before entering esophagus
Brief closure of rima glottidis required to protect airway from fluid or food particles entering the lungs
Nerves of larynx
Sensory: all sensation above vocal fold level = internal branch of superior laryngeal n
below vocal fold = recurrent laryngeal n
Motor innervation:
ALL intrinsic except cricothryoid by recurrent laryngeal.
