week 1 anatomy Nosebleeds/sinuses Flashcards
what are the nares?
nostrils
what is the septum made up from?
vomer and perpendicular plate of ethmoid bone
what makes up the roof of the ethmoid bone?
cribriform plate and crista galli (+anterior cranial fossa)
what makes up the lateral wall of the ethmoid bone?
superior and middle conchae, ethmoidal air cells, orbital plate of ethmoid (+inferior conchae)
what part of the ethmoid bone makes up the septum
perpendicular plate
where do the olfactory nerves pass through (like a sieve?)
cribriform plate
what occurs in the olfactory club and what happens to the nerves afterward?
synapse in bulb, travel through olfactory tract and into temporal lobe
what kind of # can disrupt the cribriform plate of the ethmoid bone? why is this bad?
Le Fort II & III level fractures
danger of infection spreading from the nasal cavity & paranasal sinuses into the anterior
cranial fossa
what type of cartilage is the septum made from?
hyaline
what mucosa is found in the nasal cavity?
nares=keratinised stratified squamous epithelium
respiratory epithelium =majority
olfactory mucosa = near olfactory nerves
what is CN1?
olfactory nerve
what are the concha made of?
sup and middle = part of ethmoid
inf=bone on its own
what is the somatic sensory nerve supply to the nasal cavitys??
CNv1 = anterosuperiorly
CN V2 =posteroinferiorly
describe the blood supply to the nasal cavities?
external carotid →facial→lateral nasal and septal branch of superior labial artery
external carotid→ maxillary→sphenopalatine and greater palatine arteries
internal carotid→ophthalmic artery→ anterior and posterior ethmoidal arteries
what is Kiesselbach’s (Little’s) area?
an arterial anastomosis on the nasal septum
a common site of epistaxis (nosebleeds)
what arteries AE, PE, SP, GP at little’s/Kiesselbach’s
Anterior ethmoidal artery (branch of the ophthalmic artery)
Sphenopalatine artery (terminal branch of the maxillary artery)
Greater palatine artery (from the maxillary artery)
Septal branch of the superior labial artery (from the facial artery)
Posterior ethmoidal artery debatable
what are the concha? what are the meatuses?
turbinate bone (sup, middle, inf)
‘spaces’ under each concha (sphenoethmoidal (recess), superior meatus, middle meatus, inferior meatus )
NG tube what nerve can be involved in insertion? how to confirm?
V2, Little’s area on the septum giving epistaxis.
Xray to confirm
function of nasal cavities
air passage, filters (vibrissae=small hairs), humidifies, warms, sense of smell
what paranasal sinuses are there?
1 frontal bone
x2 frontal sinuses
separated by bony septum
2 maxillae
x2 maxillary sinuses (antra)
1 ethmoid bone
x2 sets ethmoidal air cells
1 sphenoid bone
x2 sphenoidal sinuses
what are the paranasal sinuses lined by?
mucous-secreting respiratory mucosa
how does the mucus drain from paranasal sinuses?
via ostia in the lateral walls of the nasal cavities
where do the ethmoid sinuses drain?
sup and middle meatuses
where do the sphenoid sinuses drain into?
sphenoethmoidal recess
