Histology Flashcards
What does the midface develop from?
1st brachial arch and frontal process
What does the frontal process develop?
forehead
Centers around the development of the primitive mouth or stomodeum occurs by the end of what week?
3rd week
What does the median nasal process develop?
Center and tip of nose, nasal septum, globular process
What does the lateral process form?
Sides of nose and infraorbital area
Cleft is due to the failure of what?
The failure of the median nasal process merging with the globular process
What does the palate develop from?
1ST brachial arch and the frontal process
When does soft tissue of the palate fuse?
between 8 and 12 weeks gestation
What is the anterior part of the tongue derived from?
1st brachial arch
What is the posterior part of the tongue derived from?
brachial arches 2-4
What 3 swellings form the anterior portion of tongue?
Two lateral lingual swellings and the tuberculum impar
What swelling forms the posterior portion of the tongue?
copula
What does the dentition develop from
1st brachial arch and frontal process
formation of the dentition is called what and when does is begin
called odontogenesis and begins at 6 weeks gestation
Where does formation of the dentition begin
anterior part of the mandible
when does calcification begin
approximately 4th month
3 layers of tooth germ
enamel organ, dental papilla, dental sac
What is taurodontism caused by?
incomplete invagination of Hertwig’s root sheath
How is taurodontism best noted? How does it look?
Best noted on radiograph, the bifurcation area is positioned more apically
Enamel developed from what organ ?
enamel organ
What specialized cell is enamel formed by?
ameloblasts
what is the hardest tissue in the human body?
enamel
Enamel organic/inorganic percentage?
96% inorganic, 4% organic
why can’t enamel repair itself?
ameloblasts are lost during tooth eruption
Dark and light bands,
Hunter-Schreger bands
Which way do Hunter-Schreger bands run?
perpendicular to the DEJ
What are Hunter-Schreger bands caused by?
change in the direction of the enamel rods
What are lines of retzius caused by and what do they look like
They are caused by the layering process of enamel formation and from mineralization and they are fine lines that run from the DEJ to cusp tips
Enamel pearl is often mistaken for what?
calculus
What is dentin formation called
odontogenesis
What is the first tissue to be mineralized during tooth development
dentin
what does dentin develop from
dental papilla
dentin is formed from what specialized cells
odontoblasts
Where does dentin first form? Then where does it progress too?
first forms at incisal edge/cusp tips and then progresses to the root
dentin organic/inorganic material
30%organic 70%inorganic
dentin is weaker than _____ but harder than _____
weaker than enamel but harder than cementum or bone
how are tubules orientated to the DEJ and DCJ
perpendicular
Sclerotic dentin Is more common in____ and can decrease the rate of _____ spread
more common in older teeth, can decrease the rate of caries spread
formation of cementum is called
cementogenesis
cementum developed from
dental sac
what cells of the PDL form cementum
cementoblasts
where is cellular cementum primarily located?
apical and furcation areas
where is acellular cementum primarily located?
more cervical portion of the root
cementum organic/inorganic material
50%organic/ 50% inorganic material
normal width of cementum
0.05 mm wide
where is cementum the widest
root apex and furcation areas
where is cementum the thinnest
cervical 3rd of tooth
hypercementosis may be an indicator of what ?
chronic inflammation or Paget’s disease
cementum does not meet enamel ___ of the time
cementum does not meet enamel 10% of the time
cementum meets enamel ___ of the time
cementum meets enamel 30% of the time
cementum overlaps enamel ___ of the time
cementum overlaps enamel 60% of the time
pulp is formed from
the dental papilla of the tooth germ
what is the only nonmineralized tissue of the tooth
pulp
3 histologic zones of pulp
- odontoblastic zone
- cell-free zone
- cell-rich zone
primary cell of pulp
fibroblast
what does pulp contain of odontoblasts
nuclei
what are cork-screw like fibers that lie between the odontoblasts does pulp contain
Koriff fibers
the pulp contains cells that are associated with which tissue/ system
nerve tissue and vascular system
calcifications exhibited by pulp
pulp stones, denticles
What is the periodontal ligament
a thin layer of connective tissue that surrounds the root of the tooth
what specialized cells does PDL contain
cementoblasts, cementoclasts, odontoblasts, odontoclasts
what are the remnants of Hert-wig root sheath that may have a later pathological significance (tumor formation) that may be in the pulp
epithelial rests of Malassez
layers of bone/alveolar process
outer dense layer of bone is called compact bone.
inner spongelike bone is called trabecular bone
tissue composition of bone/alveolar process
50%mineralized tissue/ 50% nonmineralized tissue
the oral mucous membrane is derived from what germ layer?
ectoderm
the oral mucous membrane is the lining of the oral cavity that opens to ?
outside of the body
what tissue is the outer layer of the oral mucous membrane is
epithelial tissue
underlying layer of the connective tissue oral mucous membrane
lamina proper
the oral mucous membrane contains an outer layer of what cells
stratified squamous epithelial cells
In areas of trauma, the oral mucous membrane may exhibit
outer protective layer of epithelial cells without nuclei called keratinized tissue
dorsum of tongue mucosa
specialized mucosa
masticatory mucosa is ____ and covers ____
masticatory mucosa is keratinized and covers the gingiva and hard palate
lining mucosa is ____ and covers ____
nonkeratinized and lines nonmasticatory areas
Where is the parotid gland located? Is it bilateral or lateral?
located slightly inferior and anterior to the ear and is a serous gland. it is bilateral
what childhood infection is the parotid gland associate with?
mumps
Where does the globular max cyst occur
anterior max palate
What holds the upper lip together?
philtrum
what are 3 components of the upper lip?
right lateral, philtrum, left lateral
What does the nasopalatine injection anesthesize?
ant palate
what process does philtrum come from?
globular process
what does the globular process give rise too
philtrum, premaxillary palate
what does the maxillary process give rise to?
lateral palatine processes upper parts of cheek, sides of upper lip
what does the mandibular process give rise too?
lower jaw, lower parts of face, lower lip, anterior 2/3 of tongue
palate develops what week
between weeks 6-12
when is upper lip complete?
6-8 weeks
Tastebuds are not associated with what papillae?
filiform papillae
Where is the submandibular gland located? Is it bilateral or unilateral? Is it a serous or mucous gland?
It is located on the medial posterior part of the mandible. It is bilateral and
a serous and mucous gland
Where is the sublingual gland located? Is it bilateral or unilateral? Is it a serous or mucous gland?
It is located on the floor of the mouth. It is bilateral and a serous and mucous gland
When does development of the face begin
about week 3
Submandibular gland produces what % of saliva
Submandibular gland produces 65% of saliva
sublingual gland produces what % of saliva
Sublingual gland produces 10% of saliva
upper lip is formed by the fusion of the
median nasal process and right and left maxillary process
palate develops between what weeks
weeks 6-12
palate develops from
fusion of the globular process with the left and right palatal processes
embryonic processes fuse
anteriorly to posterior
enamel comes from
ectoderm
dentin and pulp comes from
mesoderm
mesoderm and ectoderm are separated by what
basement membrane
basement membrane gives rise to
DEJ- the junction between dentin and enamel
stages of tooth development and weeks
- Intiation (Induction) week 6-7
- Bud Stage (Profileration) week 8
- Cap Stage week 9-10
- Bell stage week 11-12
What week initiation occurs
week 6-7
What week does Bud stage (proliferation) occur
8th week
As ectoderm becomes thicker in bud stage it is called
dental lamina
What week does Cap stage occur
week 9-10
Enamel organ arises from what stage in tooth development?
CAP stage
what does the dental papilla arise from
specialized connective tissue (ectomesenchyme) or mesoderm
mesoderm is also called
ectomesenchyme
mesoderm gives rise to what part of tooth germ
dental papilla
dental sac gives rise to
PDL, alveolar bone, cementum
What week does the bell stage occur
week 11-12
The enamel organ develops 4 distinct layer?
1.Outer enamel epithelium
2.Stellate reticulum
3.Stratum intermedium
4.Inner enamel epithelium
What does the outer enamel epithelium create?*
Hertwig’s epithelial root sheath
inner enamel epithelium gives rise too
ameloblasts
dentin is formed what shape
tubular
enamel forms as what shape
rods
At what stage is there a differentiation of enamel
Bell stage
how is tooth structure produced
layer by layer (appositional growth)
tooth matrix is initially ____ then ______
tooth matrix is initially soft then mineralized
hydroxyapatite
crystalized calcium phosphate
when does root formation begin and end*
begins after the crown is complete and ends 1-4 years after eruption
the enamel organ layers condense to form the
reduced enamel epithelium
the reduced enamel epithelium gives rise to *
junctional epithelium or gingival attachement
Hertwig’s epithelial root sheath helps to
determine the outline of the root and dissolves
if hertwig’s epithelial root sheat does not dissolve is leaves remnants called
rests of mallasez
remnants of the dental lamina are known as ____ and can also develop cysts
rests of serres
most numerous papillae
filiform
elongation of filiform papillae cause what
hairy tongue
papillae that appear larger but there is fewer of them
fungiform
papillae that appear as red bump
fungiform
papillae that are folds of tissue at the posterior lateral border of tongue
foilate papillae
where are circumvallate papillae located
just anterior to the sulcus terminalis (junction of posterior 1/3 and anterior 2/3 of tongue
which papillae are 8-12 in number*
circumvallate
which papillae contain glands of von ebner
circumvallate
where is the foramen caecum found*
foramen caecum is found at the center point at the sight of the embryonic origin of the thyroid (circumvallate papillae)
submandibular gland is also known as
wharton’s duct
sublingual gland is also known as
bartholin’s duct
what gland lubricates lips and tongue
sublingual gland
sublingual caruncle contains what openings *
wharton’s duct and bartholin’s duct openings
parotid gland aka
Stenson’s duct
enamel spindle are
ends of odontoblastic processes which cross the DEJ
enamel spindles are
ends of odontoblastic processes which cross the DEJ
what forms the greatest bulk of the tooth
dentin
primary dentin is deposited when
before the completion of the root
mantle dentin is where
1st layer of dentin and is immediately adjacent to the DEJ
circumpulpal dentin is where
remaining dentin is adjacent to the pulp
secondary dentin develops when
after the tooth is in occlusion
odonntoblastic processes are found in
dentinal tubules
cementum is nourished by
PDL
cementum contains centrocytes in lacunae which are
trapped cementoblasts
concrescence is
fusion of two teeth by cementum
what does pulp contain (6)*
blood vessels, nerve fibers, fibroblasts, odontoblasts, histiocytes, pulp stones
trigeminal nerve branches and which are sensory/motor
ophthalmic (V1), maxillary (V2), and mandibular (V3) nerves
what does the VI ophthalmic nerve include? is it sensory or motor
includes tip of nose (nasociliary) eyes (lacrimal) and forehead (frontal)
it is sensory
what does the V2 maxillary include? is it sensory or motor
upper teeth, nose, palate, mouth, cheek, temporal region
it is sensory
what does the V3 mandibular include? where does it enter the mandible from? is it sensory or motor
includes muscles of mastication (motor) and lower teeth (sensory)
enters the mandible through mandibular foramen
3 divisions of the trigeminal foramina*
1st division- superior orbital fissure ( V1 Opthalmic)
2nd division- foramen rotundum (V2 Maxillary)
3rd division- foramen ovale (V3 Mandibular)
what does the motor portion of the (7) facial nerve have
muscles of facial expression
what is the sensory portion of the (7) facial nerve for /have
taste through anterior 2/3 of tongue via chorda tympani
sublingual and submandibular salivary glands (parasympathetic system
muscles of mastication innervation
mandibular (V3) division of the trigeminal
muscles of mastication blood supply
maxillary artery
muscles of mastication elevation
masseter, temporalis, medial pterygoid
muscles of mastication depression
lateral pterygoid (with hyoid muscles)
muscles of mastication protrusion
lateral pterygoid
muscles of mastication retrusion
temporalis
muscles of mastication lateral shift
lateral pterygoid
4 primary muscles of mastication
temporalis
masseter
medial pterygoid
lateral pterygoid
temporalis origin
temporal fossa (temple)
temporalis insertion
coronoid process (and mandibular posterior area to the 3rd molars )
temporalis function
to retract (retrude) and elevate the mandible
masseter origin
zygomatic arch
2 heads of the masseter muscle, how do they differ?
differ in-depth: superficial head and deep head
masseter insertion
the outer surface of the mandible
masseter function
elevate the mandible
medial pterygoid origin
medial surface of the lateral pterygoid plate and maxillary tuberosity
medial pterygoid insertion
Inner surface of mandible
medial pterygoid function
elevate and protrude mandible
lateral pterygoid muscle origin
lateral surface of the lateral pterygoid plate and infratemporal space of the sphenoid bone
lateral pterygoid muscle insertion
TMJ disc and neck of condyle
lateral pterygoid muscle function
protrudes/depress mandible
allows side to side shift of mandible (think lateral=side to side)
the lateral pterygoid muscle opens the mouth with use of ____***
hyoid muscles
muscles of facial expression innervation/blood supply
facial nerve (7) / facial artery
which muscles help us smile
zygomaticus, levator anguli oris, risorius
if the muscle of facial expression inserts into the mouth but the origin is above the mouth it will contribute to a
smile
if the muscle of facial expression inserts into the mouth but the origin is BELOW the mouth it will contribute to a
frown
levator
lifts
depressor
pulls down
anguli
angle
orbicularis
circular
oculi
eye
oris
mouth
nasii
nose
labii
lip
superioris
upper
inferioris
lower
aleque
side
buccinator muscle is a _____ _______ muscle of facial expression
buccinator muscle is a _thin____ __quadrilateral_____ muscle of facial expression
what does the buccinator muscle form
anterior part of the cheek or lateral wall within the buccal region of the oral cavity
3 origins of the buccinator muscle
- alveolar process of maxilla + mandible
- fibrous structure
- pterygomandibular raphe*
mentalis muscle origin
mandible near midline (chin)
mentalis muscle insertion
in the skin of the chin
hyoid muscles are important for
chewing, speaking , swallowing
where do hyoid muscles originate from
hyoid bone
hyoid muscles innervation
trigeminal (5) and facial (7) nerve
suprahyoid muscles are where and what is the function
above the hyoid bone and they open the mouth (depress mandible)
mylohyoid muscles make up
make up the floor of the mouth
what are the suprahyoid muscles (4)
diagastric
mylohyoid
stylohyoid
geniohyoid
where are the infrahyoid muscles
below the hyoid bone, junction at the thyroid area
what are the infrahyoid muscles
omohyoid
sternohyoid
sternothyroid
thyrothyoid
**what is the SA (SinoAtrial Node)
pacemaker of the heart, location is the right atrial wall
what supplys the heart with blood
coronary arteries
*veins carry blood ____ the heart, arteries carry blood ____ from the heart
veins carry blood __towards__ the heart, arteries carry blood __away__ from the heart
(think Artery = Away )
to measure BP u are looking for
looking for a large artery (brachial)
to measure emergency pulse for adult
carotid
to measure emergency pulse for child
brachial
to measure non-emergency pulse for adult
radial
to measure non-emergency pulse for child
brachial
**where is the mitral valve located
between the left atrium and left ventricle
what regions does the facial artery supply (6)
oral, buccal, zygomatic, nasal, orbital, infraorbital regions
how is the facial artery separated by the facial vein in the neck
by the posterior belly of the diagastric muscle, stylohyoid muscle and the submandibular gland
the pterygoid plexus drains to form ___
maxillary vein
what does the jugular vein run with?
carotid artery
if you have improper angulation during PSA block you can pierce the plexus and cause what
hematoma
what is orthostatic hypotension
drop in BP due to sudden change in posture
what can cause orthostatic hypotension
fetal pressure on the inferior vena cava
if orthostatic hypotension occurs what do u do
put cushion under RIGHT hip and roll pt onto LEFT side
lymphatic system is a network of
tiny channels and nodes
lymphocytes are derived from
stem cells in the bone marrow
the lymphatic system helps
helps venous circulation return interstitial fluid to the bloodstream from tissues in the body (key role in immune system)
where do T cells mature ***
T cells mature in the thymus
lymphocytes respond to
lymphocytes respond to foreign antigens in the tissue fluids
tender/englarged lymph notes can indicate
infection/malignancy
submental nodes drain fluid from** (5)
mandibular incisors, chin, tip of tongue, midline of lip, floor of mouth
submandibular nodes drain ***
drains the submental node and remaining teeth
may/ may not include 3rd molars
deep cervical nodes drain *
submandibular nodes, 3rd molars, wall of the throat
oropharynx drained by*
superior deep cervical nodes
superior deep cervical nodes are drained by *
inferior deep cervical nodes
tongue develops week
weeks 4-8
cleft lip is a result of
median nasal process and maxillary process fail to fuse
cleft palate is a result of? when does it occur
palatal shelves fail together or duse with the posterior portion of the primary palate
occurs 8-12 weeks
