anatomy of nasopharynx

ANATOMY OF NASOPHARYNX

SHAJAHAN.C51st BATCHMedical college calicut

A fibromuscular tube 12–14 cm long Extent: Cranial base to the level of the C6 vertebra i.e. lower border of the cricoid cartilage where it is continuous with the oesophagus.

A common passage for both food and air.

Lined my mucousa throughout. Situated posterior to the nasal and oral cavities.

RELATIONS- Sup: Posterior part of the sphenoid

body and the basilar part of the occipital bone.

Inf: continuous with the oesophagus. Post: C1-C6 vertebra & prevertebral

fascia covering longus colli and capitis. Ant: opens into the nasal cavity, mouth

and larynx. It is attached, from above downwards

on each side to: the medial pterygoid plate, pterygomandibular raphe, mandible, tongue, hyoid bone, thyroid and cricoid cartilages.

STRUCTURE OF PHARYNGEAL WALL

a)Mucous membrane The mucosa is continuous with that

lining the pharyngotympanic tubes, nasal cavity, mouth and larynx.

The nasopharyngeal epithelium is pseudostratified ciliated columnar.

Stratified squamous elsewhere.

b)Pharyngeal aponeurosis Fibrous layer lining muscular coat

c)Muscular coatd)Buccopharyngeal fascia

PHARYNGEAL MUSCULATURE

CONSTRICTORS (external layer) Superiorconstrictor

Middle

constrictor Inferior

constrictor

LONGITUDINAL MUSCLES(int layer)

Stylopharyngeus

Palatopharyngeus

Salphingopharyngeus

Thyropharyngeus Cricopharyngeus

LONGITUDINAL MUSCLES

NERVE SUPPLY BY PHARYNGEAL PLEXUS

Pharyngeal branch of vagus, cranial accessory N., glossopharyngeal N., superior cervical sympathetic ganglion.

Motor- Glossopharyngeal- Stylopharyngeus muscle cranial accessory N.- All other pharyngeal

muscles General Sensory- IX & X CRANIAL

NERVES,NASOPHARYNX-maxillery nerve Taste – Vagus Parasympathetic- greater petrosal and lesser

palatine nerves.

BLOOD SUPPLY

Ascending pharyngeal A. of External carotid A.

Ascending palatine and tonsillar branches of Facial A.

Dorsal lingual branches of Lingual A. Greater palatine, pharyngeal and

pterygoid branches of Maxillary A. Venous drainage- by pharyngeal plexus

of veins on its posterior wall and empties into the Internal Jugular vein.

LYMPHATIC DRAINAGE

Retropharyngeal and Upper deep cervical.

DIVISIONS

NASOPHARYNX

The uppermost part of the pharynx has a respiratory function.

•Is a posterior extension of the nasal cavity.

•The nose opens into the nasopharynx via to large posterior apertures called choanae.

•The roof and posterior wall of the nasopharynx form a continuous surface that lies inferior to the body of the sphenoid bone and the basilar part of the occipital bone.

Floor is formed by soft palate anteriorly.

Posteriorly deficient space-nasopharyngeal isthmus.

Anterior wall formed by choanae Lateral wall-pharyngeal opening of

ET situated 1.25cm bhind the posterior end of inf turbinate.

•Pharyngeal tonsil •Pharyngeal orifice of the auditory tube

•Tubal elevation - torus tubarius

•Nasopharyngeal bursa

•Tubal tonsil

•Rathke’s pouch

CONTENTS

Adenoids Subep collection of lymphoid tissue at the

jn of roof and post wall.Increases in size upto 6yrs and then

gradually atrophies.

Torus tubarisET bounded above and behind by an

elevation.Above and bhind the tubal elevation is a

recess-Fossa of Rossenmuller.

Nasopharyngeal bursaEp lined median recess found with in

the adenoid mass, pharyngeal mucosa to periosteum of the basiocciput.

Notochord –pharyngeal endoderm.Infected-persistent post nasal

discharge.Abscess-Thornwaldt’s Ds

Rathke’s pouchDimple above adenoidsRemniscent of buccal mucosal

invagination,to form the ant lobe of pituitary.

Craniopharyngioma may arise from it.

Tubal tonsilCollection subep lymphoid tissue situated

at the tubal elevation.

Sinus of morgagni

Crescentric interval between sup. Constrictor and base of skull above is filled up by Condensed pharyngobasilar fascia Tensor veli palatini Levator veli palatini Auditiory tube

Passavant’s ridgeMucosal ridge raised by fibers of

palatophrygeas.Encircles the post and lateral walls of

nasopharyngeal isthmus.

THANK YOU

KEMME

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