LESSON 1&2 (not Finished) (base On The Pdf) Flashcards
knowledge of facial and _________ and development, hep to treat early malocclusion through prevention, interception, or early correction of interferences
with normal development that lead to malocclusion
somatic growth
A progressive development
Growth
state of going through natural growth, differentiation or evolution through successive changes
Development
the emergence of personal characteristics or features through a growth process; attainment of adult function and size due to proliferation, differentiation, and morphogenesis
Maturation
the growth of different organs or parts at different rates
Differential Growth
DEVELOPMENT PROCESSES OF AN EMBRYO
Induction
Proliferation
Differentiation
Morphogenesis
Maturation
action of one group of cells on another that leads to the developmental pathway in the responding tissue; interaction between developing embryonic cells
Induction
cellular growth; mitosis
Proliferation
change in identical embryonic cells to become structurally and functionally distinct; process of specialization of embryonic cells
Differentiation
development of specific tissue structure or differing form due to cell migration and induction
Morphogenesis
attainment of adult function and size; emergence of personal characteristics or features through a growth process
Maturation
PERIODS OF PRENATAL HUMAN DEVELOPMENT
→ from fertilization to implantation
Period of the Ovum
PERIODS OF PRENATAL HUMAN DEVELOPMENT
→ 0-1 week
Period of the Ovum
PERIODS OF PRENATAL HUMAN DEVELOPMENT
→ 2-8 weeks
Period of the Embryo
PERIODS OF PRENATAL HUMAN DEVELOPMENT
→ largely cellular proliferation and migration
Period of the Embryo
PERIODS OF PRENATAL HUMAN DEVELOPMENT
→ differentiation of all major internal and external
organs (morphogenesis)
Period of the Embryo
PERIODS OF PRENATAL HUMAN DEVELOPMENT
→ very vulnerable stage
Period of the Embryo
PERIODS OF PRENATAL HUMAN DEVELOPMENT
→ 8 weeks to 9 months
Period of the Fetus
PERIODS OF PRENATAL HUMAN DEVELOPMENT
maturation of existing structures
Period of the Fetus
PERIOD OF THE OVUM another term
PRE-IMPLANTATION PERIOD
0 TO 3 DAYS
PERIOD OF THE OVUM (PRE-IMPLANTATION PERIOD)
During 0 TO 3 DAYS there’s a formation of zygote (spermatozoon fertilizes an oocyte) in the oviduct (ampulla of the uterine duct)
PERIOD OF THE OVUM (PRE-IMPLANTATION PERIOD)
zygote undergoes cleavage (series of mitotic divisions as the zygote moves along the uterine tube to the uterus) to form blastomeres
At what day also?
PERIOD OF THE OVUM (PRE-IMPLANTATION PERIOD)
0 TO 3 DAYS
formation of the morula which enters the uterus 3 days after fertilization
PERIOD OF THE OVUM (PRE-IMPLANTATION PERIOD)
formation of the blastocyst (a morula with a fluid-filled space called blastocyst cavity or blastocele)
PERIOD OF THE OVUM (PRE-IMPLANTATION PERIOD)
During these day
implantation
o blastocyst adheres to the surface of the endometrium
AT 6 DAYS
PERIOD OF THE OVUM (PRE-IMPLANTATION PERIOD)
formation of (2) cells from the blastocyst
Trophoblast
Embryoblast
→ outer cell mass
→ single layer of cells covering the outer
portion of the blastocyst
Trophoblast
→ develops into the placenta and other
peripheral structures associated with the embryo
Trophoblast
→ inner cell mass
→ group of cells inside the trophoblast that
develops into the embryo
Embryoblast
period of organogenesis
o 1/100 to 4/100 inch
“week of the two’s”; bilaminar disk stage
PERIOD OF THE EMBRYO (EMBRYONIC PERIOD)
formation of (2) layers from the trophoblast:
Syncytiotrophoblast
Cytotrophoblast
inner multinucleated cells
Cytotrophoblast
→ outer multinucleated cells
→ invades endometrial tissue and
erodes capillaries causing maternal blood to flow into cavities within the _____
syncytiotrophoblast
formation of a bilaminar disk from the embryoblast:
Hypoblast
Epiblast
[[[[[[[PERIOD OF THE EMBRYO (EMBRYONIC PERIOD)]]]]]
squamous or cuboidal cells adjacent to the blastocyst cavity
Hypoblast
→ later known as the primitive yolk sac
→ primitive endoderm
Hypoblast
columnar cells that is separated from the cytotrophoblast by space called amniotic cavity, primitive ectoderm
Epiblast
trilaminar disk stage
THIRD WEEK OF EMBRYONIC DEVELOPMENT
→ gastrulation (the bilaminar disk is converted into a trilaminar
disk)
THIRD WEEK OF EMBRYONIC DEVELOPMENT
period of the “three’s”
o formation of the (3) embryonic or germ layers
o formation of the primitive streak, notochord, and neural
tube
THIRD WEEK OF EMBRYONIC DEVELOPMENT
begins when the primitive streak is formed; its formation will cause the disk to have right and left half wherein each half will be a mirror of the other
TRILAMINAR DISK
a narrow trough with slightly bulging sides that develops in the midline of the epiblast toward the caudal end; develops when ectodermal cells along the central axis proliferate to form a rounded elevation that later becomes a linear structure
Primitive Streak
located at the cranial end of the primitive streak
Primitive Pit
elevated portion around the primitive pit; mesodermal cells that will form the notochord
Primitive Node
movement or migration of cells to the primitive streak and primitive node which detach from the epiblast and continues to grow beneath the epiblast
INVAGINATION
innermost layer composed of cells that displace the hypoblast
Endoderm
composed of cells between the endoderm and the epiblast; formed by the movement of some cells of the epiblast toward the hypoblast at the primitive streak
Mesoderm
composed o the remaining cells of the epiblast
Ectoderm
cells that invaginate into the primitive streak and node grows cranially to form a cellular rod called the ___________ that runs longitudinally in the midline of the trilaminar disk
notochordal process
→ represents the early midline of the embryo where the axial skeleton will form
→ future site of the vertebral column
NOTOCHORD
At the end of the third week, the total length is ______
1.0 mm
> 5mm
> embryo begins to form a tubular structure
FOURTH WEEK OF EMBRYONIC DEVELOPMENT
in front of the primitive streak is the _____
primitive node
mesodermal cells that will form the notochord
primitive node
a neural plate forms
neuroectoderm
also have differentiation of cells from the ectoderm to form the _____
neuroectoderm
At the end of the third week, the total length is.
1.0 mm
embryo folds along this tube–results from extensive proliferation of the ectoderm and the differentiation of specific tissues at the cephalic end
What week?
FOURTH WEEK OF EMBRYONIC DEVELOPMENT
folding results in the formation of the primitive oral
cavity
stomodeum
development of a head fold
What week?
FOURTH WEEK OF EMBRYONIC DEVELOPMENT
head formation
- rostral or head fold
- anterior portion of the neural tube expands as the forebrain, midbrain, and hindbrain
What week?
FOURTH WEEK OF EMBRYONIC DEVELOPMENT
→ process of the development of the neural tube from the closure of the neural plate and neural fold
NEURULATION
→ day18
→ occurs when the notochord and adjacent mesenchyme causes the
ectoderm to form the neural plate
→ mesodermal cells that will form the notochord
NEURULATION
thickening of the ectoderm over the notochord that will fold to form the neural groove
Neural Plate
cells of the neural plate
Neuroectoderm
elevated lateral edges of the neural plate; form the cells of the neural crest
Neural Folds
→ cells from the neural folds
→ migratory (migrates throughout the
body and differentiates into various
structures)
→ population of cells
Neural Crest Cells
multipotent
Neural Crest Cells
gives rise to ectodermal tissues and
mesenchyme in specific areas of the head/face
Neural Crest Cells
provides the embryonic connective tissue needed for craniofacial development (face, neck, and oral tissues)
Neural Crest Cells
a groove located between the neural folds
that fuses to form the neural tube
Neural Groove
result of the fusion of the neural folds at the midline on the fourth week of development that will later give rise to
the
brain and spinal cord
Neural Tube
portions of the mesoderm that do not form the notochord divide into sections called
somites
→ specific body regions and structures
→ masses of mesoderm along the sides of the neural tube to form
the striated muscles of face, jaw and throat, dermis, and
vertebrae
somites
Number of somite pairs give rise to most of the skeletal structures of the
head, neck, and trunk
38
located on either side of the neural tube to give rise to skeleton
and muscle tissue
SOMITES
True or false
1st occipital and 5th to 7th coccygeal disappear while the rest
form the axial skeleton
True
the flat trilaminar disk folds to form the typical ____-shaped embryo
C
due to the folding of the endodermal-lined yolk sac into the embryo
formation of the primordial gut (foregut, midgut, and hindgut)
consists of bilaterally paired arches, 5 pouches (clefts), 6 grooves and membranes
PHARYNGEAL (BRANCHIAL) APPARATUS
fissures that separate the pharyngeal arches on the external surface of the embryo
Pharyngeal Grooves or Clefts
separates the arches on the inner surface of the embryo; represents the extensions of the development pharynx between the inner surface of the adjacent pairs of arches
Pharyngeal Pouches
tissue between the pouches and clefts that connects the adjacent arches
Pharyngeal Membranes
has a major role in the formation of structures of the head and neck (face, oral cavity, nasal cavities, pharynx, larynx)
PHARYNGEAL (BRANCHIAL) APPARATUS
6 pairs of bars that form lateral or at the sides of the primordial pharynx (develops from the foregut) that develops due to the migration of neural crest cells into the head and neck region
PHARYNGEAL ARCHES
True or false
the fifth arch disappears soon after formation
True
True or false
the first 4 arches are well-developed in humans
True
only the first and second arches extend to the ___
midline
the 3rd, 4th, 5th arch are divided in the midline by the
developing ____
heart
What composed of PHARYNGEAL ARCHES?
each has a nerve, cartilage, and arterial component
all structures that form the arch are innervated by the
associated ____
cranial nerve
only groove that gives to structure in the adult
Groove 1
Groove:
derivative: external auditory meatus
Groove 1
gives rise to the cervical sinus that becomes obliterated during the development of the neck
Groove 2
In PHARYNGEAL MEMBRANE, membrane 1 forms the _____
tympanic membrane
True or false
In PHARYNGEAL MEMBRANE, the remaining membranes regress
True
derivatives:
o tympanic cavity
o auditory or Eustachian tube
o mastoid antrum
PHARYNGEAL POUCHES 1
derivatives:
o crypts of palatine tonsil
PHARYNGEAL POUCHES
derivatives:
o inferior parathyroid gland o thymus
PHARYNGEAL POUCHES 3
derivatives:
o superior parathyroid gland
o parafollicular cells (cells that produce calcitonin)
PHARYNGEAL POUCHES 4
regresses
What PHARYNGEAL POUCHES?
PHARYNGEAL POUCHES 5
ectodermal swellings or prominences that are
filled with mesodermal and neural crest cells
primordia
True or false
EVENTS IN THE FORMATION OF FACIAL STRUCTURES
fusion of the medial ends of the mandibular processes in the midline for the chin and lower lip
True
5TH WEEK
→ nasal placodes develop_______ on the surface ectoderm on the lower part of the frontonasal prominence
bilaterally
5TH WEEK
___________ proliferates at the margins of the placodes and produces the medial and lateral nasal processes that transforms the placodes into nasal pits (future nostrils)
mesenchyme
the lateral nasal processes is separated from the maxillary process by a groove called the __________ which disappears to form the nasolacrimal duct
nasolacrimal groove
the developing eyes comes forward to the face as the
frontonasal prominence ______
narrows
6TH WEEK
→ the medial nasal processes merge in the midline to form the ________
intermaxillary segment
6TH WEEK
will give rise to the center of the upper lip, philtrum, primary palate, and part of the alveolar process for the upper incisors
intermaxillary segment
→ lateral portion of upper lip
→ upper cheek
→ secondary palate
Maxillary Processes
→ forehead
→ dorsum and bridge of nose
Frontonasal Prominence
→ intermaxillary segment
→ midline of nose
→ nasal septum
Medial Nasal Processes
ala of the nose
Lateral Nasal Processes
entire upper lip
Medial Nasal Prominence and Maxillary Processes
→ external nose
Frontonasal Prominence, Medial, and Lateral Nasal Processes
→ lower lip
→ lower cheek → chin
Mandibular Processes
DEVELOPMENT OF THE PALATE
Week?
6 to 12 weeks
→ the triangular shaped part of the palate anterior to the incisive foramen
→ arises from the intermaxillary segment
Primary Palate
→ gives rise to the hard and soft palate posterior to the incisive foramen
→ arise from the internal aspect of the maxillary processes as lateral palatine shelves
Secondary Palate
→ initially, the ______ are widely separated since they project vertically on each side of the tongue
lateral palatine processes
clinical remnant of the fusion of the palatine shelves
Median Palatine Raphe
marks the junction of the primary palate and the lateral palatine shelves
Incisive foramen
a congenital abnormality that results from the failure of the fusion of the medial nasal processes and maxillary processes
Cleft Lip
a congenital abnormality that results from the failure of the fusion of the lateral palatine shelves to each other, with the nasal septum, or with the primary palate
Cleft Palate
DEVELOPMENT OF THE TONGUE starts with the enlargement of the ____
tuberculum
impar
the mucosa of the posterior 1⁄3 or base of the tongue develops
from the _______
hypobranchial eminence
the V-shaped demarcation or line of fusion between the body and base of the tongue
Terminal Sulcus or Sulcus Terminalis
the point where the first and 2nd arches unite and is located at the apex or just behind the terminal sulcus in the midline
Foramen Caecum
facial nerve
Taste Buds
trigeminal nerve
Body of the Tongue
glossopharyngeal nerve
Base of the Tongue
hypoglossal nerve
Skeletal Muscle of Tongue
True or false
first structure to develop in the lower jaw:
o mandibular division of the trigeminal nerve
True
at 6 weeks:
__________ extends or forms a solid hyaline
cartilaginous rod surrounded by a fibrocellular capsule
Mecke’s cartilage
at 7 weeks:
_______ spreads anteriorly and
posteriorly to form the bone of the mandible
intramembranous ossification
True or false
at 10 weeks:
o rudimentary mandible is formed
True
ossifies by intramembranous ossification
Calvaria
ossified by endochondral ossification
Cranial Base
term for developing organism (fetus)
Week?
from 8 weeks
o face is well formed
o tooth buds appear
Week?
at 9 weeks
sucking motions are made in the mouth
Week?
at 10 weeks
What arch number?
Maxillary artery
I
(Mandibular)
What arch number?
Hyoid and Stapedial Arteries
II
(Hyoid Arch)
What arch number?
Internal Carotid Artery
III
What arch number?
Subclavian Artery (left side of the arch)
- right side of the arch contributes to the arch of the aorta, pulmonary arteries*
IV
At the end of 3rd week OF EMBRYONIC DEVELOPMENT the total length is _____.
1.0 mm
At what period and week will it begins to form a tubular structure?
Period of embryo, 4th week
What period and week folding of embryo start?
Period of embryo, 4th week
At what week and period will the development of pharyngeal arches begin?
Period of embryo, 4th week
At what week and period does facial prominence formed?
Period of embryo, 4th week
During the DEVELOPMENT OF THE FACE at 4th week, what will formed first?
Mandible
At the end of 5th week the size is?
8mm
6-7th week size
13 mm
Maxillary processes continue to increase in
size:
- laterally, fuses with the mandibular processes (_____)
Cheek
Maxillary processes continue to increase in
size:
medially, compresses the medial nasal processes and fuse (___)
upper lip
At what week the medial nasal swellings enlarge, grow medially, fuse to form the intermaxillary segment
7week
At what week, Breakdown of buccopharyngeal membrane?
5 weeks
What week?
Primitive skull and primitive palate
6th week
critical period in DEVELOPMENT OF THE
PALATE:
6 to 9 weeks
What arch?
Body of the tongue
1st
What arch?
Base of the tongue
2-4th arcg
Weeks?
primary palate
5 to 6 weeks
Week?
secondary palate
6 to 12 weeks
Week?
final palate
12 weeks
2 primordia
- Primary palate
- Secondary palate
from deep part of intermaxillary segment
(median palatine process)
True or false
Fusion of the palatine shelves occurs first just posterior to the primary palate
Tru
Anterior 2/3 is invaded by bone
HARD PALATE
Posterior part is invaded by muscles to form the soft palate
SOFT PALATE
Incisive suture = union of primary and secondary
palate
SOFT PALATE
palatine raphe = union of lateral palatine sheves
SOFT PALATE
• within the fourth week
• two bulges form inferior to the stomatodeum
Development of the Mandible
In what week of the mandible intramembranous ossification begins in this mesenchyme and spreads anteriorly and posteriorly to form the ramus and body
7 week
Rapid ossification backward and away from the Meckel’s cartilage from a point of divergence (lingual)
Ramus of the mandible
Enumerate the pharyngeal cartilage
Meckel’s Cartilage
Reichert’s Cartilage
Part of the Hyoid Cartilage
Laryngeal Cartilage
What nerve?
Base of the Tongue
glossopharyngeal nerve
What nerve?
Body of the Tongue
trigeminal nerve
What arch?
Muscles of the Pharynx and Larynx
IV
What arch?
Muscles of Mastication
I
What arch?
mandible
I
middle ear ossicles–malleus and incus
from the dorsal end of the Mecke’s cartilage
What arch?
Internal Carotid Artery
III
