Oral nasal cavities Flashcards
Infraorbital region
Bellow the orbital region
Between zygomatic and nasal region
Tubercle
Tip of upper lip
Outline of lip
Vermillion border (loose with age )
Corner of the mouth
Labial commissure
Facial cleft occur at
Any boundary btwn prominences
Placode thickening is induced by
It’s is the thinking of ectoderm
Induced by the brain
Nose is called
Nasal/olfactory placode
Medial and lateral prominences develop and form
Nasal pit
Ectodermal invagination
Nasal pit moves
Dorsally (makes a depression)
Medial and Lateral prominence merge to form
Nasal Sac
(Ectoderm)
Nasal Plug
(Epithelial plug that will degenerate)
Nasal placode swells
outward and surrounding the tissue will also swell making the nasal placode look sunk in `
Nasal sac and stomodeum ingvaginate
dorsally
both are ectodermaly lined
What happens week 5 in the nasal and oral cavity ?
oronassal membrane degrades
What happens in week 6 to the nasal and oral cavity ?
The two cavities join
Choanae: posterior nasal apartaures
primary palate
oral and nasal cavity total communication
Mekel’s cartilage
arch 1 (max and mand)
majority is associated with the mandible it does not ossify but rather signals for other cells to ossify. Only bone that directly come from mekel’s is malleus
What are the four sinuses
maxillary
ethmoid
frontal
sphenoid
Sinuses and nasal cavities form from
outgrowths of nasal cavity called Diverticulations
what are some functions of sinuses
give resonance of the voice
lighten the skull
humidifies air (helps)
buttresses: Nasomaxillary
Maxillary sinus form during
Late pregnancy
When does the frontal Sinus form?
Forms at 2 years old from Ethmoid sinus
when does ethmoid and sphenoid sinuses form?
form after birth
What humidifies air the most ?
nasal cavities
Nasal cavity histology (3) :
pseudostratified columnar epithelium with cilia
goblet cells- rest on the basement membrane
vascular lamina propria- warms the air
Paranasal sinuses histology differences
thinner than the nasal mucosa with fewer goblet cells
Lamina propria
connective tissue with vasculature
Olfactory epithelium differences only in the superior part of nasal cavity
Bipolar olfactory nerve cells
formed from ectoderm
attach to olfactory blub
pseudostratified columnar epithelium
all cells rest on the basement membrane
Development of the lower face
within 4-5 weeks
arch 1
two bulges form inferior to the stomatodeum
What is Meckel’s cartilage
the cartilage of the first branchial arch associated with the formation of the mandible
6 weeks meckel’s cartilage forms a
Rod surrounded by a fibrocellular capsule
Mandible formation
two Meckel’s cartilage but do not meet at the midline
separated by a thin line of cartilage called symphysis
what occurs on the lateral aspect of the symphysis in the mandible formation?
condensation of mesenchyme forms
At 7 weeks what kind of ossification forms the mandible bone ?
Intramembranous
ossification in the mesenchyme
How does the ramus of the mandible develop ?
rapid ossification posteriorly into the mesenchyme of the first arch
How does the mandible form/ connect at mid line?
intamembranous ossification spreads anteriorly until midline.
the bones do not fuse at midline –> mandibular symphysis forms (from Meckel’s cartilage)
When does the mandible fully fuse ?
shortly after birth
Meckel’s cartilage role is…
signals mesenchyme around it to ossify –> then the Meckel’s cartilage disintegrates
Meckel’s cartilage does not ossify
What two structures directly come off from Meckel’s cartilage?
- posterior portion- malleus of the inner ear
2. sphenomandibular ligament
Most of Meckel’s cartilage is
resorbed entirely
Most anterior portion of Meckel’s cartilage near the midline contributes to the jaw via …
endochondral ossificaiton
Anterior Palate
Posterior Palate
Anterior Palate = hard palate
posterior palate= soft palate
Pterygomandibular fold/raphe
relax when swallowing large things
goes from distal mandibular tooth to the area between the mandible and the point at which the hard and soft palates
When does the palate begin to form until when ?
Palate begins to form at 5-6 weeks until 12-13th week
Palate formation develops from two segments :
Primary Palate/Pre-maxilla
Secondary Palate
the will fuse together
Primary palate formation
Median Nasal Processes fuse and form:
Intermaxillary Segments
Intermaxillary Segment
Forms from the Intermaxillary Segment then :
Median Palatine process –>
Fuses to form the primary palate ( hard palate)
What makes up the hard palate ?
- Intermaxillary Segment
( which formed from the Median Nasal Processes) - Some of the lateral shelves
What makes up the secondary palate ?
Has some hard and some soft palate
What makes up the soft palate?
Lateral Shelves
Uvla?
Obstructs nasal cavity while swallowing ( Soft palate)
The oronasal cavity is bounded
anteriorly by the primary palate and occupied by the developing tongue
When can the the oral and nasal cavities be distinguished?
after the development if the secondary palate
Maxillary process form:
Lateral palatal processes ( **fuse from anterior to posterior)
What are the three outgrowths that appear in the oral cavity?
Nasal Septum
2 palatine shelves
What need to get out of the way so that the palatine shelves can fuse (secondary palate formation)?
the tongue
The nasal septum grows? Encounters?
grows downward through the oral cavity
encounters the primary and secondary palates
When do nasal septum and shelves fuse ?
By the 12th week
Completion of Palate
- Lataeral Palatal Shelves and Nasal septum for ventrally ( downward)
- Posterior part of primary palate meets the secondary palate and gradually fuse
- Mandibular growth releases tongue
What need to occur before the primary palate and the secondary palate fuse together ?
The tongue need to get out of the way
What releases the tongue?
Mandibular growth
Fusion of plate leaves space for the
Incisive Canal/Nasopalatine canal
Primary Palate goes from
Incisive Foreman to distal lateral incisors
Secondary Palate goes from and includes …
Incisive foreman to Uvula
Includes: Maxilla Palatine bones Soft Palate Uvula
Cleft treatment options
soft tissue -corrective surgery
hard tissue - obturator, partial dentures (kiddy partials)
Development of tongue
From which arch?
Arch 1-Oral part of tongue (anterior 2/3)
Arch 3- Pharyngeal part of tongue (posterior 1/3)
Which arches do not contribute to the tongue ?
Arch 2- contribution to the surface is lost
Arch 4- epiglottis and adjacent regions
Germ cells of the tongue are:
Arch 1= anterior 2/3= ectoderm
Arch 3= posterior 1/3= endodermal
How does the anterior part of the tongue form?
lateral lingual swelling
median tongue bud (tuberculum impar)
How does the posterior part of the tongue form?
Copula/hypobranchial eminence
Where does the copula/ hypobranchial eminence form from?
2nd 3rd and 4th branchial arches
When the copula/hypobranchial eminence fuse it becomes …
the adult terminal sulcus
Anterior 2/3 muscle formed from
occipital somites ( which migrate into the tongue area)
External tongue muscle
slide 37
What do the occipital somites form ?
( Anterior tongue muscles)
Intrinsic muscles of the tongue
longitudinal, vertical and transverse muscles 1
slide 37
What does the extrinsic tongue muscles form and attach to?
(Anterior tongue muscles)
have one attachment outside of the tongue
Muscles: Palatoglossus Hyloglossus Styloglossus Genioglossus
Histology of the ventral side of tongue
lining mucosa
Non- keratinized stratified squamous epithelium
Histology of the dorsal surface of the tongue
- Specialized mucosa (Keratinized stratified squamous epithelium)
- Papillae
- Taste Buds
- Glands ( serous and mucous)
All papillae are extensions of the
nervous system that can sense chemicals
Circumvallate (vallate)
7-12 large domed papillae arranged in a v just anterior to the sulcus terminalis
have taste buds
Foliate
(papillae)
low parallel ridges on the lateral edge of tongue
have taste buds
Fungiform
(Papillae)
mushroom shaped papillae that look like small spots
have taste buds
Filiform
(Papillae)
smallest and most numerous papillae. Conical shape with highly keratinized epithelium
no taste buds
Which papillae have taste buds
Circumvallate
Foliate
Fungiform
Filiform
What are the types of Papillae
Circumvallate
Foliate
Fungiform
Filiform
What Papillae does not have taste buds
Filiform
Hairy Tongue is due to
caused by fungal/ bacterial infection
increased by dehydration, alcohol and tobacco
