Anatomy  of pharynx
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Anatomy of pharynx

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  • nice work ....very elaborately.....
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  • Very good. Is there any axial CTscan delineation of Pharyngeal constrictors available/ Thanks
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Anatomy  of pharynx Anatomy of pharynx Presentation Transcript

  • ANATOMY OFPHARYNXKEERTHI NS2010 BATCH
  • An overview Pharynx is a conical fibromuscular tube forming the upper part of air and food passages 12-14cm long Width :3.5cm at base; 1.5cm at pharyngo- oesophageal junction
  • PHARYNX
  • Division of Pharynx a)Base of skull(basioociput and basi sphenoid) soft palate b)Plane of hard palate hyoid bone c) Hyoid bone lower border of cricoid cartilage
  • STRUCTURE OFPHARYNGEALWALL From outwards: a) Mucus membrane b) Pharyngeal aponeurosis c) Muscular coat d) Buccopharyngeal fascia
  • Mucus membrane• Pseudostratified ciliated columnar(in nasopharynx)• Stratified squamous epithelium Pharyngeal aponeurosis • Pharyngobosilar fascia • Fibrous layer lining muscular coat Muscular coat • Longitudinal muscles(internal layer) • Constrictors Buccopharyngeal fascia • Covers pharynx externally • Pharyngeal plexus of nerves
  • Pharyngeal Muscles LONGITUDINAL MUSCLES Stylopharyngeus Palatopharyngeus Salpingopharyngeus• O:medial aspect of • O: upper surface • O: cartilage of the styloid process of palatine auditory tube near• Gap between aponeurosis as 2 the pharyngeal middle and fasiculi opening of it. superior • Moves along inner constrictor aspect of the• NS: constrictor glossopharyngeal • NS: pharyngael plexus All the 3 are inserted as a conjoint sheet at the post border of thyroid cartilage and lat aspect of epiglottis
  • Superior Constrictor Lies in wall of nasopharynx and oropharynx Wide origin  Post border of med pterygoid plate &pterygoid hamulus  Pterygomandibular raphae  Post end of mylohyoid line  Mucus membrane on side of tongue Lower part covered by middle constrictor.
  • Middle Constrictor Hypopharynx O: lower part of stylohyoid ligament lesser and greater cornu of hyoid Inferiorly overlapped by inferior constrictor.
  • Inferior Constrictor Thickest of the 3 Thyropharyngeus obliquely displaced O:oblique line of thyroid cartilage inferior cornu of thyroid Cricopharyngeus transversly displaced O: ant part of cricoid cartilage between attachment of cricothyroid and articulation of inferior cornu
  • Cricopharyngeus Muscles of 2 sides act as a sphincter Function– prevent the entry of air in to the oesophagus in the interval between swallowing So sphincter relaxes during swallowing Contracts between the acts of swallowing.
  •  All of the fibres get inserted into the median fibrous raphaeExtending from Constrictors Pharyngeal tubercle oesophagus
  • Killian’s Dehiscence Potential gap b/w weak area ofpharyngeal wall Gateway of Tear perforation can occur at this site during oesophagostomy.
  • Killian’s Dehiscence
  • PHARYNGEAL SPACES 2 potential spaces in relation to pharynx: Retropharyngeal space:  Situated behind pharynx  Extends from base of skull to the bifurcation of trachea Parapharyngeal space:  Situated on the side of pharynx  Contains carotid vessels, jugular veins, last four cranial nerves & cervical sympathetic chain
  • Pharngeal Plexus of NervesAlmost all of the nerve supply to the pharynx, whethermotor or sensory, is derived from the pharyngeal plexus Formed by the pharyngeal branches of theglossopharyngeal and vagus nerves with contributionsfrom the superior cervical sympathetic ganglion.The pharyngeal branch of the vagus supplies all the musclesof the pharynxExcluding stylopharyngeus, which is supplied by theglossopharyngeal nerve
  • NASOPHARNX / EPIPHARYNX  Roof  Post wall  Floor  Ant wall  Lat wall
  • Nasopharynx Uppermost part Behind nasal cavitiesExtents: Base of skull to soft palateRoof: Basisphenoid and basiocciputPosterior wall: Arch of atlas vertebra Pre vertebral muscles Fascia
  • Nasopharynx (contd)Floor: Ant:soft palate Post: deficit(nasopharyngeal isthumus)Ant wall: Posterior nasal apertures or choanae Posterior ends of nasal turbinates and meatus are seen
  • Nasopharynx (contd)Lat wall: Presents pharyngeal opening of eustachian tube situated 1.25cm behind the posterior end of inferior turbinate Bounded above and behind by an elevation called TORUS TUBARIUS raised by the cartilage of the tube. ◦ Above and behind the tubal elevation is a recess called fossa of Rosenmuller-commonest site for origin of carcinoma. ◦ Salpingopharyngeal fold-A ridge extending from lower end of the TT to the lateral pharyngeal wall;raised by salpingopharyngeus
  • NASOPHARYNGEALTONSIL(ADENOIDS) Subepithelial collection of lymphoid tissue. At the junction of roof and posterior wall of nasopharynx. Causes the overlying mucous membrane to be thrown into radiating folds. Increases in size up to the age of six years and then gradually disappears.
  • Nasopharyngeal Bursa Epitheliallined median recess found within adenoid mass Extends from pharyngeal mucus to periosteum of basiocciput. Represents the attachment of notochord to pharyngeal endoderm during embryonic development Infected pharyngeal bursitis post nasal discharge or crusting Abscess in the bursa:Thornwaldt’s disease
  • Rathke’s Pouch Clinically represented-A dimple above the adenoids Reminiscent of buccal mucosal invagination to form the anterior lobe of pituitary Carcinopharyngoima may arise
  • Tubal tonsil Collection of subepithelial lymphoid tissue Sit. at tubal elevation Continuous with adenoid tissue and forms a part of Waldeyer’s ring. CA: When enlarged due to infection, it causes eustachian tube occlusion.
  • Sinus of Morgagni:space b/w base of skull & upper free border of sup.constrictor Pierced by:  Eustachian tube  Levator veli palatini  Tensor veli palatini  Ascending palatine artery
  • FOSSA OF ROSENMULLER Pharyngeal recess Commonest site of nasopharyngeal carcinoma Malignant growth may infilterate adjacent structuresBrain Soft palate Auditory tube nasal cavity
  • Passavant’s Ridge  A mucosal ridge raised by fibres of palatopharyngeus.  Forms a ring around post and lat walls of nasopharyngeal isthmus.  When soft palate is elevated the muscle band appear as a ridge Passavant’s ridge  During act of swallowing palate and the ridge approximated.
  • Lymphatic DrainageUpper deep cervical nodes Retropharyngeal nodes Parapharyngeal nodesSpinalaccessory chain of nodes in theposterior triangle of the neck.
  • Functions Acts as a conduit for air;b/w nose and larynx. Ventilates midle ear through eustachian tube and equalises air pressure on both sides of TM. Cuts off nasopharynx from oropharynx with the help of Passavant’s ridge. Acts as a resonating chamber for voice production Acts as a drainage channel for mucus secreted by nasal and nasopharyngeal glands
  • OROPHARYNX Boundaries • Roof • Post wall • Ant wall • Floor • Lat wall
  • Oropharynx Extends from the plane of hard palate to the plane of hyoid bone. Lies opposite to the oral cavity, Through oropharyngeal isthmus,it communicates with oral cavity.OROPHARYNGEAL ISTHMUS-boundaries. Soft palate above. Upper surface of tongue below. Palatoglossal arch on either sides.
  • Boundaries of oropharynxPosterior wall Related to retropharyngeal space. Lies opposite the second and upper part of third cervical vertebrae.Anterior wall Deficient above Below,it presents: ◦ Base of the tongue , posterior to circumvallate papillae ◦ Lingual tonsils ◦ Valleculae
  • Valleculae Cup shaped depressions Lying b/w the base of the tongue and anterior surface of epiglottis. Bounded medially by the median glossoepiglottic fold Laterally by pharyngoepiglottic fold
  • Boundaries of oropharynx [cont…] Lateral wall presents: ◦ Palatine tonsil ◦ Anterior pillar:palatoglossus muscle ◦ Posterior pillar: palatopharyngeus muscle Tonsillar fossa A triangular depression b/w the anterior and the posterior pillars. Lodges palatine tonsils
  • Lymphatic Drainage Upper jugular chainjugulo-digastric nodes ◦ Retropharyngeal and parapharyngeal nodes Posterior cervical group Function Conduit passage for air and food Helps in pharyngeal phase of deglutition Forms part of vocal tracthelp in speech Helps in appreciation of taste Provide local immunity and defense against harmful intruders
  • Laryngopharynx / Hypopharynx Lowest part of pharynx Above oropharynx Below oesophagus Ant laryngeal cavity Laryngeal inlet
  • ClinicallyPyriform sinus Post-cricoid Post-pharyngeal (fossa) region wall
  • Pyriform sinus / fossaBoundaries Lat:thyrohyoid memb & thyroid cartilage Med:aryepiglottic fold, postero lateral surfaces of arytenoid and crocoid cartilage Forms lateral channel for food Smuggler’ fossa Foreign bodies may get lodged here Internal laryngeal nerve in submucosa of latera wall; easily accessible for LA CA: pain is referred to ear in Ca of pyriform sinus
  • Pyriform sinus / fossa Extent Pharyngoeppiglottic fold to upper end of oesophagus
  • Post-cricoid regionPart of: CA: Ant wall of  Commonest site for laryngopharynx carcinoma in females between upper and suffering from lower border of Plummer-Wilson cricoid lamina syndrome
  • Post-Pharyngeal WallEXTENTS FROM: Hyoid bone to the level of cricoarytenoid joint
  • FunctionCommon pathway for air and foodHelp in deglutitionProvides a vocal tract for resonance ofcertain speech sounds.
  • Lymphatic Drainage Pyriform sinus drains intoupper jugular chainRich lymphatics  high frequency of nodalmetastasis in carcinoma of this region Post cricoid  parapharyngeal nodes Post wall parapharyngeal nodes or lateral pharyngeal nodes
  • Waldeyer’s Ring A ring composed of MALT at beginning of food and air passage. Produce B and T lymphocytes Local defense Also produce lymphocytes to send to other lymph nodes.