Click here to load reader
Upload
arvind-sangavi
View
391
Download
56
Tags:
Embed Size (px)
Citation preview
Anatomy of PharynxDr. B. Arvind Sangavi
M.S.(ENT)Associate ProfessorDept of ENT & HNS
RIMS
PharynxPharynx is a conical fibromuscular tube
forming upper part of aero-digestive tract12-14 cms, extends from base of skull to
lower border of cricoid cartilage (C6).Width is 3.5 cms at base & 1.5 cms at
pharyyngo-oesophageal junction, which is the narrowest part in GIT.
Mucous membranePharyngeal aponeurosis / Pharyngobasilar fascia
Muscular coatBuccopharyngeal fasciaCiliated columnar in nasopharynx &
stratified squamous in rest of pharynx
Killian’s dehiscenceInferior constrictor muscle- thyropharyngeus –oblique fibres
cricopharyngeus – transverse fibresPotential gap- Killian’s Dehiscence“Gateway of tears” – perforation can occur at
this site during oesophagoscopy.Pharyngeal pouch- herniation of pharyngeal
mucosa
Waldeyer’s RingSubepithelial layer of lymphoid tissueNasopharyngeal tonsil/adenoidsPalatine tonsilTubal tonsilLateral pharyngeal bandsNodules-posterior pharyngeal wall
Pharyngeal SpacesRetropharyngeal space- from base
of skull to bifurcation of trachea between buccopharyngeal fascia & prevertebral fascia. Divided by median raphe into two (space of Gillette)
Prevertebral space - between vertebral bodies & prevertebral fascia, extends from base of skull to coccyx
Parapharyngeal spaceMedial: buccopharyngeal fascia covering
constrictorsPosterior: prevertebral fasciaLateral: medial pterygoid muscle,
mandible.Styloid complex- divides into anterior &
posterior compartment. Antr- tonsillar fossa medially & pterygoid
muscle laterally Postr- pharyngeal wall med & parotid
laterally. Carotid art, jugular vein, IX, X, XI, XII CN, & nodes
PharynxNasopharynx, Oropharynx & HypopharynxNasopharynxEpipharynx: from base of skull to plane
passing through hard palateRoof: basisphenoid & basiocciputPosterior wall: atlas vertebra with musclesFloor: anteriorly soft palate & posteriorly
communicates with the oropharynx through nasopharyngeal isthmus
Lateral wall: E.tube 1.25cms behind IT Torus tubaris- elevation behind tubal opening Fossa of Rosenmuller- site for origin of
Nasopharyngeal Carcinoma Salpingopharyngeal foldTubal tonsil: part of Waldeyer’s ring
Adenoids-Nasopharyngeal tonsil upto12 years, later atrophies
Nasopharyngeal bursaEpithelial lined median recess within adenoids
Extends from pharyngeal mucosa to basiocciput
Represents attachment of notochord to pharyngeal entoderm during embryonic life
Infection – persistent postnasal discharge
Thornwaldt’s disease- abscess
Rathke’s pouch: remniscent of buccal mucosal invagination,forming antr lobe of pituitary. Craniopharyngioma may arise from this site
Sinus of Morgagni: space between base of skull & upper free border of superior constrictor . E.tube, tensor veli palatine, levator veli paltine enters along with ascending palatine artery br of facial artery
Passavant’s ridge: mucosa ridge raised by palatopharyngeus. Deglutition, cuts off NP from OP
Lined by pseudostratified ciliated columnar epithelium
Lymphatics drain into upper deep cervical nodes either directly or thro’ retro/parapharyngeal nodes
FunctionsConduit of humidified air into larynx/tracheaVentilates ME thro’ E.tube, equalizes air
pressure.Cuts off oropahrynx during deglutition, vomiting,
speechResonating chamberDrainage channel for mucous secreted by nasal
glands
Oropharynx Extends from plane of hard palate above to plane of
hyoid bone belowCommunicates with oral cavity thro’ oropharyngeal
isthmus.Posterior wall: related to retropharyngeal space, C2-C3Anterior wall: above opens into oral cavity, & below
related to base of tongue, lingual tonsil, valleculaeLateral wall: anterior & posterior pillars, faucial tonsilLower limit is by upper border of epiglottis &
pharyngoepiglottic folds
Lymphatics drain into upper jugular chain-JD nodes, also to retro & para pharyngeal nodes.
FunctionsConduit for passage of air & foodPharyngeal phase of deglutitionVocal tract for certain speech soundsTaste sensation-BOT, soft palate, pillars,
PP wallLocal defence & immunity at entrance of
aerodigestive tract- Waldeyer’s ring
Hypopharynx (Laryngopharynx)It lies behind & sides of larynxExtends from plane passing from hyoid
bone to lower border of cricoid cartilage, (C3-C6).
Three regions: Pyriform sinus, post cricoid region & posterior pharyngeal wall.
Pyriform fossa: either side of larynx. Internal laryngeal nerve runs submucosally in lat wall, cause referred pain in carcinoma
Post-cricoid region: cricoid lamina, site for carcinoma in pt’s with Plummer-Vinson syndrome
Posterior pharyngeal wall: from level of hyoid bone to crcoarytenoid joint.
Lymphatic drainage: upper jugular chain, parapharyngeal nodes, supraclavicular.
Functions:Conduit for air & food, Vocal tract resonanceTakes part in deglutitionFailure of cricopharyngeal sphincter to relax
when pharyngeal muscles contract- hypopharyngeal diverticulum
Structures passing throughAbove superior constrictorE.tube, tensor palati, levator palati musclesPalatine br ascending pharyngeal arteryBetween superior & middle constrictorStylopharyngeus muscle, glossopharyngeal nBetween middle & inferior constrictorInternal laryngeal n, superior laryngeal vessels.Below inferior constrictorRecurrent laryngeal nerve, inferior laryngeal
art
Blood supply: branches of external carotid artAscending pharyngeal, Dorsal lingual arteryAscending palatine & tonsillar arteryBranches of internal maxillary arteryNerve supply: pharyngeal plexus formed byPharyngeal br of vagus & glossopharyngealPharyngeal br of superior cervical
sympathetic ganglionVagal fibres are motor, glossopharyngeal is
sensory & sympathetic is vasomotor
Functions of PharynxDeglutitionProtection from aspirationPart of respiratory & food passageSpeech adds resonance to the voiceWaldeyer’s ring is involvedTaste sensationMucous from respiratory tract is
swallowedE.tube ventilates & drains the middle ear
cleft
Thank You..