LEC64: Nose and Paranasal Sinuses Flashcards
identify important structures
where is the superior conchi
what are functions of nasal cavity? importance?
1) olfaction- for quality of life, not survival
2) respiration- matters for survival
what are macrosomatic animals
animals that use smell as primary sense- for detection of prey, spotting water resources, etc
nose’s general function re: air and inspiration?
nose prepares air - warms it to at or near body temperature - before it passes to lower respiratory tract
how much air does nose condition daily?
10,000-20,000 L of air daily
what is state of breathed air, what must happen to it?
air contains billions of infectious, allergenic, irritative, toxic materials
air must be filtered, neutralized, eliminated
identify:
root of nose, nasion, dorsum, margin, tip, ala, naris, columella
what is piriform aperature
border of nasal cavity, entry portal to upper respiratory system
looks like a pear
components of piriform aperature?
maxilla and nasal bones
where is nasal cavity proper?
inside piriform aperature
bony partition divides nasal cavity into 2
concha bullosa?
an inflated turbinate
normal unless impedes flow of air through nasal cavity- then problematic
how many turbinates?
3- superior, middle turbinate, inferior turbinate; in nasal cavity proper
what is the nasal septum?
perpendicular plate of the ethmoid
identify the bones
crista galli- anterior cranial fossa entry, connects to falx cerebra (orange/yellow at top)
PP: perpendicular plate of ethmoid, intrudes at midline
C: cartilagenous component
V: vomer
M: maxatine cavity- crest that arises above nasal cavity floor
P: palatine cavity- crest that arises above nasal cavity floor
what is this? how is it visualized? ID parts
nasal cavity wall, visualized by removing nasal septum
what must blood supply to nasal cavity pass through?
pterygomaxillary fissure
where is pterygopalatine ganglion? what is there with it?
through pterygopalatine fissure, in pterygopalatine fossa
find branches of CN V, trigeminal there also
what is maxillary artery? what is it a branch of? where does it travel through? where does it end up?
a terminal branch of external carotid a
goes through pterygomaxillary fissure, into pterygopalatine fossa, into sphenopalatine foramen, into nasal cavity proper
ID structures 10, 12
10: nasal septum, reflected superiorly
12: sphenopalatine artery - very thick!
what is arterial supply of nasal cavity wall?
1) maxillary branch of external carotid artery
1) postero-lateral superior branch of sphenopalatine a
2) postero-lateral middle branch of sphenopalatine a
3) postero-lateral **inferior **branch of sphenopalatine a
2) opthalmic branch of internal carotid artery
1) anterior ethmoidal** **branch of opthalmic a
2) posterior ethmoidal branch of opthalmic a
identify the arteries
where does greater palatine artery enter nasal cavity?
greater palatine foramen
hugs oral cavity
identify these holes
greater palatine foramen- where greater palatine a comes out, greater palatine nerve
lesser palatine foramen
where does greater palatine artery enter nasal cavity floor
incisive foramen
septal artery function?
facial artery branch
goes superiorly; connects w/ dorsal nasal artery at orbit
connection between a nasal and an eye-related artery?
external carotid > facial a > dorsal nasal a > opthalmic a
describe all arteries of eye orbit
“place of least resistance” principle?
ethmoidal arteries go through bone
surgeous can go through solid bone if have to, because if artery going thru bone by def’n, have osseus tunneling already, just have to snip to get pathologic site they want to access
what is this
anterior and posterior ethmoid foramena, where ethmoid artery goes through ethmoid bone
where do nasal bleeds occur?
little’s area
major nervous contribution to nasal cavity?
branches of V2, maxillary a
nasopalatine n location
hugs nasal septum
descends through incisive canal
sends branches to incisive dentition
pterygopalatine ganglion sends branches where
nasal septum, wall
branches of pterygopalatine ganglion in the nasal cavity are?
superior, middle, and inferior postero-lateral nasal branches
4 sinuses?
frontal
sphenoidal
maxillary
ethmoidal
roles of sinuses?
1) architectural: reduce cranial weight, shock absorption, accomodate growth, replace functionless bone
2) physiological: produce fluid for humidification, ventilation, secrete mucus, air conditioning, shock absorption, impart resonance to voice, aid in respiratory function
3) evolutionary residuals: had a fxn once that’s no longer needed
identify frontal and maxillary sinuses. should they be a/symmetrical?
frontal: asymmetric
maxillary: symmetric
which paranasal sinus develops first, embryologically?
maxillary sinus
begins as bud along inferoalteral surface of ethmoid portion of nasal capsule
day 65
borders of maxillary sinus?
roof: floor of orbit
floor: dental roots
embryologic cell type of nasal cavity cells?
mesenchymal cells
what element of vault grows uniquely in humans only?
maxilla grows vertically
how does maxillary sinus grow?
medial > lateral
when do molar teeth erupt?
6 yrs old: 1st moral erupts
12 yrs old: 2nd moral erupts
17-25 yrs old: 3rd molar erupts
where is maxillary sinus floor re: nasal cavity floor?
in fetus, maxillary sinus floor is above level of floor of nasal cavity
in grown person, maxillary sinus floor is below the level of the nasal cavity floor
where do V2 branches go re: paransal sinuses?
V2 branches hug around maxillary sinus
autonomic innervation to lacrimal gland?
presynaptic: greater petrosal n., of VII, to pterygopalatine ganglion
postsynaptic: zygomatic n., lacrimal n.
distribution root: V1, V2
autonomic innervation to mucous glands, nasal cavity, nasopharynx, palate?
presynaptic: VII via greater petrosal n.
ganglion: pterygopalatine
postsynaptic: branches of V2
what is within sinus wall epithelium that is the target for GVEs?
respiratory epithelial lining has serous glands, mucous glands, goblet cells
this is postganglionic GVE target
descrbe path of greater petrosal n > target glands
preganglionic parasympathetic fibers exit from midbrain
enter internal acoustic meatus
at GENICULATE BEND, greater petrosal n goes thru pterygoid canal
synapses at pterygopalatine ganglion
rides w/ V2 to get to target glands
what is middle conchi
middle turbinate w/ epithelial lining
what are 3, 5, 7?
3, inferior turbinate
5, middle turbinate
7, suprior turbinate
lamina papyracea?
paper thin part of ethmoid bone
where ethmoid sinus air cells are
each air cell has an opening
are unique to individuals
what is norm for frontal sinus morphology?
asymmetric
what lines sinuses?
respiratory epithelium
they produce fluid, which must drain
identify hiatus semilunaris
anterior face of ethmoid bullop, sliver that is posterior bone of ulcinate process
what space is entered from the hiatus semilunaris?
ethmoid infindibulum
is the receptical space for frontal, maxillary, ethmoid inner sinuses
components of middle turbinate?
horizontal, vertical, superior components
so attachment to middle turbinate is in 3 dimenstions, very solid
3 categories of sphenoid sinus?
1) conchal - tiny
2) pre-sellar - neumitization remains in front of sella turcica
3) post-sellar - neumitization grows beyond sella turcica
what leaves an imprint on walls of sphenoid sinus?
optic nerve
what is wrong with this pt?
papilloma in R eye, affecting his abducens
cannot abduct eye
how does infection get to middle ear from sinus?
via eustachian tube
how do lacrimal tears travel and where do they drain?
lacrimal tears bathe the occular globe from superolaterally > inferomedially
drain into **inferior meatus **
what drains into middle meatus?
frontal, maxillary, anterior ethmoid sinuses
what drains into superior meatus?
sphenoid, posterior ethmoid sinuses
what drains into inferior meatus?
lacrimal tears
what is unique about sphenoid sinus drainage?
sphenoid drains into superior meatus
but must go through posterior ethmodi sinus to get to superior meatus
all other sinuses have direct route of drainage to their meatus
