Lecture 10.2 Nasal cavity gateways and neurovascular Flashcards
What neurovascular structures enter/ exit nasal cavity through the Cribriform plate- on the roof
- Fibres of CN1
- Anterior ethmoidal nerve (from V1) and ant., post ethmoidal arteries + accompanying veins
- In some individuals,
Nasal veins (connecting to the superior sagittal sinus through foramen cecum- danger zone)
What neurovascular structures enter/ exit nasal cavity through the Sphenopalatine foramen - on the lateral wall
- Sphenopalatine branch of the maxillary artery
- Nasopalatine nerve (branch of maxillary nerve (V2))
- Superior nasal branches of maxillary nerve (V2)
What neurovascular structures enter/ exit nasal cavity through the Incisive canal - on the floor
- Nasopalatine nerve (from nasal to oral cavity)
2. Terminal end of the greater palatine artery (oral cavity to nasal)
What neurovascular structures enter/ exit nasal cavity through the Small foramina in the lateral wall - posterior
- Branch of the Greater palatine nerve (V2)
What neurovascular structures enter/ exit nasal cavity through looping around the margin of the naris - to go to lateral wall
(small foramina in the lateral wall category*)
- Branch of the infra-orbital nerve (V2)
2. Alar branches of nasal artery (from facial artery)
What nodes does the lymph drain to and what bv does it run with
Lymph runs with the veins, draining to the submandibular, deep cervical and retropharyngeal nodes
Where do the nasal veins drain to
Pterygoid plexus which includes the facial, ophthalmic, and inferior cerebral vein.
What is the arterial supply to the lower anterior septum on the Medial Wall
-called Little’s area and
what is the clinical significance
Area of great anastomoses between
- Septal branch of the Superior Labial artery
- Ascending branch of greater palatine artery
- Sphenopalatine artery (posterior septal branch- only small)
4) Septal branches of the Anterior and Posterior ethmoidal artery
called Kieselbach’s plexus which is the common site for anterior epistaxis- nosebleed. This must be checked for submucosal haematoma and drained after trauma otherwise cartilage death
What is the arterial supply to the lateral wall and what is the clinical significance (3)
- Sphenopalatine artery (Mainly)
- Anterior and Posterior Ethmoidal arteries
- External nasal artery is a branch from ant ethmoidal. - Alar branch of lateral nasal artery
Because Sphenopalatine artery is a continuation of the maxillary artery, posterior bleeding of this artery due to systemic hypotension, etc is life threatening as leads to hypovolemic shock.
This bleed needs to be fixed by an ENT surgeon.
What are the arterial bv for the nose that originate from internal carotid and where do the rest originate from
- Int Carotid = anterior and posterior ethmoidal arteries
All the others originate from the external carotid artery
What is the nerve supply to the 3 regions of the nasal cavity
- Olfactory: olfactory receptors - extensions of olfactory nerve cn1
- Vestibular: Infra-orbital nerve (CNV2)
- Respiratory area:
a)Anteriorly by the
- anterior ethmoidal nerve
+ anterior superior alveolar nerve
b) Posteriorly by branches from the
- pterygopalatine ganglion
+ greater palatine nerve
Compare the nerves that innervate the lateral vs medial wall of the nasal cavity
For both
- CN1 and Anterior ethmoidal nerve, - has septal branches
Medial wall also has -Nasopalatine nerve
Lateral wall also has branches of
- Lateral nasal nerves (superior and inferior),
- Anterior superior alveolar nerve,
- infra-orbital nerve
What cranial nerves responsible for general sensation and secretomotor innervation of mucous glands
Gen sensation: CNV1 and CNV2
Secretomotor: Parasymp fibres from CN7 which mainly joins branches of V2 in the pterygopalatine fossa
