ENT - 1 (nose) Flashcards
what forms the medial/septal wall?
- septal cartilage is anterior bit (wobbly front of nose)
- perpendicular plate of ethmoid bone (superior posterior part)
- inferior posterior part is vomer
what forms the lateral wall of nose? (like outside)
front wobbly bit is made by alar cartilage & lateral cartilage
- at top is nasal bone
what are the foramina of nasal cavity & where are they in the cavity? (4)
- anterior & posterior ethmoidal foramen (come from ethmoid bone at top of nasal cavity)
- sphenopalatine foramen (at back in between superior & middle concha)
- incisive canal (comes through maxilla at bottom of cavity)
what arteries come through the foramina of nasal cavity?
- anterior & posterior ethmoidal arteries (internal carotid to opthalmic which gives off these 2 which come through anterior & posterior ethmoidal foramen)
- sphenopalatine artery (branch of maxillary from external carotid) comes from sphenopalatine foramen
- greater palatine artery from maxillary (from external carotid) goes through incisive canal
what artery supplies
a) outer nose
b) side of nose
c) anterior nasal septum
a) facial artery
b) lateral nasal artery
c) septal branches
what is kiesselbach’s plexus?
= plexus in anterior nasal septum (common site for epistaxis - blood vessels superficial & easily damaged)
what are arteries in kiesselbach’s plexus? (5)
- anterior ethmoidal (from ophthalmic - internal carotid)
- posterior ethmoidal (from ophthalmic - internal carotid)
- sphenopalatine artery (from maxillary - external carotid)
- greater palatine (from maxillary - external carotid)
- superior labial artery (from facial artery - external carotid)
what cells line nasal vestibule?
nasal vestibule = very front of nose at nostrils, lined by stratified squamous epithelium
what cells line nasal cavity?
main bit of nasal cavity = lined by resp epithelium
superior nasal cavity (where smell receptors) is olfactory epithelium
what is process of olfaction?
- olfactory epithelium in superior nasal cavity contains olfactory receptor cells
- odor molecules bind to olfactory receptors triggering action potential
- olfactory nerve (CN I) transmits signal through cribriform plate of ethmoid bone & synapses in olfactory bulb
- after synapse - olfactory tract carries to temporal lobe & olfactory areas of brain
what nerves supply nasal cavity?
upper 1/2 = CN V1 (ophthalmic division of trigeminal nerve) via anterior ethmoidal nerve
lower 1/2 = CN V2 (maxillary division of trigeminal) via nasopalatine & postero-superior & inferior lateral nasal nerves
which foramen in cranial fossa do each of the cranial nerves exit through?
I = cribriform plate
II = optic canal
III, IV, V1 & VI = superior orbital fissure
V2 = foramen rotundum
V3 = foramen ovale
VII, VIII = internal acoustic meatus
IX, X, XI = jugular foramen
XII = hypoglossal canal
what is the ala, philtrum, dorsum of nose?
ala = side nostril
philtrum = line along middle between nose & lip
dorsum = bridge of nose
what are the recess & concha of nasal cavity?
(from superior to inferior)
- sphenoethmoidal recess
- superior concha
- superior meatus
- middle concha
- middle meatus
- inferior conha
- inferior meatus
what are the 4 paranasal sinuses?
- frontal sinus
- maxillary sinus
- ethmoidal air cells
- sphenoid sinus
what is semilunar hiatus?
a curved groove in middle meatus = allows maxillary, frontal & ethmoidal sinuses to drain
what is choanae?
back bit of nasal cavity where nasopharynx starts
what is torus tubarius?
soft tissue tube that protects opening of eustachian tube in nasopharynx (canal from middle ear to throat)
what is the rima glottidis?
space between true vocal cords
