Nasal septum/ medial nasal wall

Nasal septum/ medial nasal wall


INTRODUCTION:

  • The nasal septum  separates the left and right airways in the nose, dividing the two nostrils.
  • It is depressed by the depressor septi nasi muscle.

ANATOMY:

Columellar septum

  • It is formed of columella.
  • Containing the medial crura of alar cartilages united together by fibrous tissue.

Membranous septum:

  • It lies b/w columella and caudal border of septal cartilage
  • No bony or cartilaginous support
  • Above two parts freely movable from side to side 

Septum proper:

  • Consist of osteocortilaginous frame work
  • Its main Constitutes are:-
  1. Perpendicular plate of ethmoid
  2. vomer bone
  3. Large septal cartilage (quadrilateral) wedged between the above two bones anteriorly

Minor contributions:

  1. Crest of nasal bone
  2. Nasal spine of frontal bone
  3. Rostum of sphenoid
  4. Crest of palatine bone
  5. Crest of maxilla and anterior nasal spine of maxilla
  • Amongst all above, nasal septum is mainly formed by vomer, perpependicular plate of ethmoid & septal cartilage.

BLOOD SUPPLY:

ARTERIAL SUPPLY:

  • Internal carotid system:
  • Branches of opthalmic artery
  1. Anterior ethmoidal artery 
  2. Post ethmoidal artery  

 External carotid artery system:

  • Spheno palatine artery (maxillary)
  1. Nasopalotine branches
  2. Post nasal septal branches
  • Septal branch of great palatine artery (maxillary)
  • Septal branch of superior labial artery(Facial) 
  • LITTLE’S AREA (KIESSELBACH’S PLEXUS)
  • Most common cause for nose bleeding is trauma to little’s area
  • Most common site for nose bleeding in children.

Region in the anteroinferior part of the nasal septum where four arteries anastomose to form a vascular plexus. The arteries are:

  1. Anterior ethmoidal
  2. Septal branch of supeior labial
  3. Septal branch of sphenopalotine
  4. Septal branch of greater palatine                  

 → Most of the lower part of nasal cavity & nasal septum is supplied by External carotid artery.

→ The top of the nasal cavity & nasal septum is supplied by Internal carotid artery.

VENOUS DRAINAGE:

  • Posteriorly through sephenopalatine veins into pterygoid venous plexus.
  • Anteriorly drain into facial veins.
  • Superiorly in ethmoidal veins.

NERVE SUPPLY OF NASAL SEPTUM:

Olfactory nerves

  • Carry sense of smell
  • Supply olfactory region of nose
  • Can Carry sheath of dura, archnoid and pia matter

Nerves of common sensation

  • Anterior ethmoidal nerve
  • Branches of nasopalatine nerve
  • Branches of infra orbital nerve 

Autonomic nerve:

  • Parasympathetic nerve fibers supply nasal glands and control nasal secretions
  • Greater superfacial petrosal nerve.
  • Sympathetic nerve fibers
  • Upper two thoracic segments
  • Deep petrosal nerve 

LYMPHATIC DRAINAGE:

  • Submandibular lymph nodes
  • Rest of nasal cavity drain into upper jugular nodes directly or through retropharyngeal nodes.
Exam Question
 
  • Kiesselbach’s area or little’s area involves 4 arteries anastomosis that are Anterior ethmoidal, Septal branch of supeior labial, Septal branch of sphenopalotine & Septal branch of greater palatine
  • Anterior ethmoidal artery supplying nasal septum is a branch of opthalmic artery.
  • Kisselback’s plexus is situated in anteroinferior part of the nasal septum.
  • Structures that forms nasal septum are columella, Membranous septum, ethmoid, vomer bone, septal cartilage, Crest of nasal bone, Nasal spine of frontal bone,Rostum of sphenoid, Crest of palatine bone & Crest of maxilla and anterior nasal spine of maxilla
  • Anterior half of the nasal septum drain to the submandibular node.
  • Most common cause for nose bleeding is trauma to little’s area.
  • Most common site for nose bleeding in children is little’s area.
  • Apple jelly nodules on the nasal septum are found in cases of Lupus Vulgaris.
Don’t Forget to Solve all the previous Year Question asked on Nasal septum/ medial nasal wall

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