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:-
- Perpendicular plate of ethmoid
- vomer bone
- Large septal cartilage (quadrilateral) wedged between the above two bones anteriorly
Minor contributions:
- 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
- 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
- Anterior ethmoidal artery
- Post ethmoidal artery
External carotid artery system:
- Spheno palatine artery (maxillary)
- Nasopalotine branches
- 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:
- Anterior ethmoidal
- Septal branch of supeior labial
- Septal branch of sphenopalotine
- 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
