UNIT 5: Nasal and Oral Cavities Flashcards
the nasal cavity has ____ and _____ components, and is lined with _____. It is a large cavity divided into 2 _______ by _____
bony and cartilaginous
ciliated mucous membrane
slit like spaces by septum
what are the 5 boundaires of the nasal cavity
anterior
posterior
superior
inferior
lateral
anterior boundary of the nasal cavity is the
nostrils
posterior boundary of the nasal cavity is the
choanae
superior boundary of the nasal cavity is the
nasal bones, frontal bone, ethmoid
inferior boundary of the nasal cavity is the
maxilla and palatine bones
lateral boundary of the nasal cavity is the
maxilla and palatine bones (+ conchae (from ethmoid and inferior nasal conchae))
describe the lateral walls of the nasal cavity
irregular, 3 scroll-shaped nasal conchae (or nasal turbinates)
describe the medial wall of the nasal cavity
smooth, bony posteriorly, cartilaginous anteriorly
olfactory bulb (where olfactory nerve fibres synapse) sits right on top of
cribriform plate (of ethmoid bone)
describe the paranasal air sinuses
- hollow cavities lined by mucous membrane; extensions of nasal cavity
- located in front, ethmoid, sphenoid, maxillary bones
what is the nose comprised of
alar cartilage, muscle, epithelium
what are the lips comprised of
muscle, mucous membrane, epithelium
describe the buccal cavity, boundaries?
smallest cavity
bw lips and cheek and gums
includes superior/inferior labial frenulum
opening of parotid duct
boundaries:
lips, cheesk, teeth and gingiva, retromolar trigone
frenulum
mucosal fold
what are the 4 boundaries of the oral cavity
teeth and gingiva
floor (tongue)
hard palate
faucial pillars
what are the two functions of the palate
controls degree of coupling bw the nasal cavity and vocal tract during speech… aka seals the pharynx and nasal cavity for sounds (looser seal)
seals off the nasal cavity during swallowing (tighter seal)
what are the two parts of the palate
bony anterior - hard palate
muscular posterior - soft palate aka velum
hard palate is formed by the fusion of 4 bones…
maxillary bone - 2 palatine processes are fused at midline
palatine bone - 2 horizontal plates are fused at midline and anteriorly w palatine processes of maxillae
the hard palate is covered w ….
mucosa that is tightly bound to bones
describe the mucous covering the hard palate
stratified squamous epithelium and submucosal mucous glands
anterior portion has 3-4 folds - rugae
midline ridge or raphe marks line of fusion
describe the soft palate
mobile muscular structure
the soft palate has an anterior attachment to free border of _____ ______ via _____ _______, forms the …
palatine bones
via palatal aponeurosis
forms the soft core of the soft palate, which is covered by muscles and mucosa
posterior edge of the soft palate is….
“free” - uvula hangs inferiorly
the soft palate at rest allows for communication bw ….
nasal cavity and vocal tract
on contraction the soft palate allows for ….
velopharyngeal closure or retro-oral seal
what are the two elevators of the soft palate
levator veli palatini
musculus uvulae
levator veli palatini: O, I, A, Inn
O = petrous portion of temporal bone; inferior aspect of cartilaginous eustachian tube
I = palatine aponeurosis (superior aspect)
A = elevates soft palate
Inn = pharyngeal branch of CN X thru the pharyngeal plexus; possibly CN XI
Musculus uvulae: O, I, A, Inn
O = posterior nasal spine of palatine bones; palatine aponeurosis
I = mucous membrane at inferior end of uvula
A = may play a role in soft palate elevation, inc bulk on nasal surface of palate for velopharyngeal closure
Inn = pharyngeal branch of CN X via the pharyngeal plexus; possibly spinal accessory nerve (XI)
the tensor veli palatini has 2 portions:
1 - flat, triangular tendon
2 - muscular portion
tensor veli palatini: O, I, A, Inn
O = scaphoid fossa of sphenoid, spine of sphenoid (next to foramen spinosum), and lateral cartilaginous walls of eustachian tube
I = tendon that hooks around hamulus of medial pterygoid plate to insert into the palatine aponeurosis and palatine bones
A = flattens and tense soft palate; opens eustachian tube during yawning and swallowing
Inn = CN V
what are the two depressors of the soft palate
palatoglossus
palatopharyngeus
what does the palatoglossus form
palatoglossal arch
palatoglossus: O, I, A, Inn
O = inferior surface of palatine aponeurosis
I = transverse and posteriolateral muscular portion of tongue
A = lifts tongue and pulls backward, depresses soft palate; constricts the posterior limits of the oral cavity (constricts the isthmus)
Inn = pharyngeal branch of CN X via the pharyngeal plexus; possibly spinal accessory nerve
palatopharyngeus forms the
palatopharyngeal arch
palatopharyngeus: O, I, A, Inn
O = palatine raphe (aponeurosis)
I = posterior border of thyroid cartilage, inferior portion of pharynx
A = lifts the pharynx and larynx, directs bolus into pharynx during swallowing; pulls soft palate down
Inn = pharyngeal branch of CN X via the pharyngeal plexus; possibly spinal accessory nerve
Structures of the face and neck in the human embryo are derived from a series of ….
arches, clefts, pouches
arches and clefts arise externally at the _____ end of the embryo around the _________
anterior
upper end of the foregut (primitive pharynx)
pouches arise ______ - are the ______ partners of the external clefts
internally
internal
arches _____ dev in humans, but arch ___ disappears during dev
1-6
5
each arch is lined with _____ internally and _____ externally… _____ and ____ in between
endoderm (resp and gastro sys) and ectoderm (skin and NS) ….mesoderm and neural crest cells in bw
bw consecutive arches, ectoderm and endoderm move closer together, which form… ____ appear in the ectoderm, _____appear in the endoderm
pharyngeal clefts and pouches
clefts
pouches
_____ arches are clearly visible on lateral human embryo; well dev by start of __ week of dev
4 (1-4 arches)
4th week
the 4 arches surround the….
primitive pharynx aka foregut
each arch gives rise to 4 components:
muscular
cartilaginous/skeletal
nervous
vascular
mesoderm in the arches forms into
vasculature and musculature
ectoderm in the arches forms the
NS derivatives, skin, bones, cartilage
the 1st arch is the
mandibular arch
what are the 2 components of the 1st arch (mandibular)
maxillary process
mandibular process
the maxillary process of the 1st arch forms the…
upper jaw, plays a major role in forming the upper part of the face
the mandibular process of the 1st arch forms the…
lower jaw, by fusing w the mandibular process from the other side of the pharyngeal apparatus
what are the nerve, muscle, skeletal components of the 1st arch (mandibular)
nerve = trigeminal CN V
muscle = muscles of mastication; anterior belly of digastric, mylohyoid, tensor tympani, tensor veli palatini
skeletal = malleus, incus, mandible
the 2nd arch is called the
hyoid arch
the 2nd arch (hyoid) has what nerve, muscle, and skeletal components
nerve = facial CN VII
muscle = of facial expression, posterior belly of digastric, stylohyoid, stapedius
skeletal = stapes, styloid process, lesser cornu of hyoid, upper part of body of hyoid
what are the nerve, muscle, skeletal, vasculature components of arch 3
nerve = glossopharyngeal CN IX
Muscle = stylopharyngeus
skeletal = greater cornu of hyoid, lower part fo body of hyoid
vasculature = common carotid artery
what are the nerve, muscle, skeletal, vasculature components of arch 4
nerve = vagus X - Xph
muscle = palate, pharynx, cricothyroid
skeletal = thyroid, arytenoids, cricoid, corniculate, cuneiform, epiglottis (same as 6)
vasculature = arch of aorta, pulmonary arteries (same as 6)
what are the nerve, muscle, skeletal, vasculature components of arch 6
nerve = vagus X - RLN
muscle = intrinsic muscles of larynx
skeletal = thyroid, arytenoids, cricoid, corniculate, cuneiform, epiglottis (same as 4)
vasculature = arch of aorta, pulmonary arteries (same as 4)
what is the buccopharyngeal membrane?
membrane lies bw 1st arches, below the rapidly dev head of the embryo
the buccopharyngeal membrane separates the _____ from the external enviro of the embryo
primitive pharynx (aka foregut)
the buccopharyngeal membrane _____ around day 24 - results in the formation of the _______
ruptures
stomodeum (primitive mouth)
the buccopharyngeal membrane rupturing allows for…
amniotic fluid to circulate thru embryo, and begins the dev of the pharyngeal apparatus and the formation of the face and neck
upper part of the face, nose and palate are formed by the _______ and the ______ of the __ arch
frontonasal process and maxillary processes of the 1st arch
to form the face, maxillary processes grow ….
forward and fuse w the downward growing frontonasal process
the line of fusion during the forming of the face is where?
from medial eye, down the lateral margin of the nose, along the phitral ridges of the upper lip
philtrum, columella, nasal alae, nasal septum are derived from the
frontonasal process
how does the nose start to form?
two thickenings on frontonasal process - called nasal placodes
as the nasal placodes continue to grow, they become more depressed and are called
nasal pits
tissue around the nasal pits form…
medial and lateral nasal folds
nasal pits deepen to form ______, ______ ruptures eventually, which establishes …
nasal sacs
nasal placodes
establishing communication bw external environment and common oronasal cavity (no palate yet)
the frontonasal process grows into the area bw the nasal pits, which forms the
primary palate and nasal septum
at the end of dev the primary palate forms…
a triangular section of the hard palate - contains the front 4 maxillary teeth (inscisors), and ends at incisive fossa
primary palate is also called the
premaxilla
what are the palatine shelves
projections on the medial aspect of each maxillary process, grow horizontally
the palatine shelves are forced to grow…
downward due to position of dev tongue
as the mandible grows, ____ moves out of the way, ____ re-orient into horizontal position
tongue
shelves
fusion of the palate begins near the ______ of the shelves and proceeds ______ and _____, which forms _____
middle portion
anteriorly and posteriorly
midline raphe
anterior end of the palate fuses w the
primary palate of the frontonasal process
posterior end of the fusion line of the palate is where the _____ is
uvula
________ grows downward from base of skull and fuses w the superior surface of the palatine shelves
nasal septum
fusion of the palate is completed by ____ week, anterior portion becomes _____ to become the _____ and posterior to nasal septum becomes ______ aka the ______
9th
ossified, hard palate
fibromuscular, soft palate
clefts =
deficits in fusion
clefts can occur
along any line of fusion
cleft lip
along philtrum, fusion bw maxillary process and frontonasal process
bilateral (both sides affected) or unilateral (one side affected)
cleft palate =
fusion bw palatine processes of maxillary process
what are two clefts we dont often see?
mandibular or facial clefts
FNP and arch 1 didn’t fuse… rare bc of survival rate
Mandibular cleft would be right in the midline bc that’s where it fuses w other thing
Submucous cleft palate
mucosa has fused in the midline but it is hiding a bony cleft palate underneath – diagnosed w feeling the palate, can also shine a light in the nose and see translucency
