Facial Development Flashcards
____ was thought to represent a portion of the tuberculum impar (branchial arch II) that persists, but now it is considered to be a result of a fungal infection (candida)
Median Rhomboid Glossitis
The blastocyst also develops an inner cell mass at days 6-7 and thereafter is referred to as the ______
embryoblast
____ brachial arch on outside grows down and covers and overgrows 3rd and 4th arches and leaves the cervical sinus
2nd
What is the stage of human development called from 9 weeks to term?
Fetal Development Period
As the body develops the head gets _____ in relation to the rest of the body over time
smaller
Space in between front teeth is known as ____
diastima
Sensory to the extreme posterior 1/3 via
the superior laryngeal branch (nerve)
Vegas (C-X)
_____ cartilage forms the mandible, maleus, and incus
Meckel’s
Small depression at the back of the tongue where thyroid forms; tissue on the back of the tongue invaginates in and makes small ball and differentiations into thyroid after descending
Foramen cecum
What is the stage of human development called from 0 -3 weeks?
Proliferation period
Branchial arch 6 is innervated by what cranial nerve?
CN XII
If one child is born with cleft lip, there is a ___% chance of a second child exhibiting the same defect
40%
_____ mesoderm is around the axis or middle
Paraxial mesoderm
____ is the precursor for posterior part of the tongue
Hypobranchial eminence
Enlargement of the amniotic cavity and migration of cells out of the hypoblast to form _______; will form the internal lining of the blastocyst cavity
Heuser’s membrane
______ is characterized by thyroid tissue on top of the tongue
Ectopic Lingual Thryoid
Fusion of the palatine shelves normally begins during ____ week of gestation and is completed by ____ week
Begins 8th week; completed by 12th week
What are the 3 components of the primitive streak?
Pit, node, and groove
Branchial arch 1 gives rise to what structures?
Median tongue bud, foramen cecum, and lateral lingual swellings
Branchial arch 4 is innervated by what cranial nerve?
CN X
The 4th branchial pouch gives rise to _____
superior parathyroids/ultimobranchial body
Motor to all tongue muscles (nerve)
Hypoglossal (C-XII)
Special sensory (taste) to anterior 2/3 via the chorda tympani branch (nerve)
Facial (C-VII)
______ is a cleft in epiblast that begins to invaginate in forming a 3rd layer (mesoderm)
Primitive Streak
Failure of thyroglossal duct to involute; located in midline of neck
Thyroglossal Duct Cyst
Ethanol, Tetracycline, Dilantin, Lithium,
Methotrexate, Warfarin, Thalidomide,
Androgens, Progesterone, Retinoic Acid are _____ that are known teratogens involved in congenital malformations
Drugs
The inner mass of the embryoblast transitions into the _________
bilaminar embryonic disc
____ is an extrusion of a ventricular cistern plus neural tissue
Meningoencephalocele
The ear develops from 6 _____?
Hilla
____ is an extrusion of dura and arachnoid mater out of the head
Meningocele
Implantation of the embryoblast in the uterine wall begins at day ____ and is complete at day ____
begins day 4; complete at day 10
What embryonic germ layer arises from the hypoblast layer?
Endoderm
The 64 cell stage morula develops an internal blastocystic cavity and thereafter is referred to as a ______
blastocyst
What are the 2 layers of the bilaminar embryonic disc?
Epiblast and hypoblast
____ occurs along the sternocleidomastoid muscle if cervical cyst doesn’t resorb
Lateral Cervical cyst
_____ is a fatal defect characterized by lack of development of the cranium and brain
Anencephaly
What are the 4 branchial arch cartilages?
Meckel’s, Reichart’s Greater horn of hyoid and thyroid cartilage
____ is the precursor for the anterior part of the tongue
Lateral lingual swellings
What percent of all clefts are isolated cleft lip?
25%
What 2 embryonic germ layers arise from the epiblast layer?
Ectoderm and Mesoderm
The _____ functions as a primitive skeletal support of the embryo around which the axial skeleton later forms; also induces formation of somites,
Notochord
____ is a mass lined with tissue that is hollow
cyst
The 1st branchial pouch gives rise to _____
eustachian tube
Branchial arch 3 is innervated by what cranial nerve?
CN IX
What are the 4 processes in the development of the face?
Mandibular, maxillary, lateral nasal, and median nasal
Defective fusion of the medial nasal process with the maxillary process results in _____
Cleft lip
Branchial arch 2 gives rise to what structure that gets overgrown?
Copula/ Tuberculum Impar
Defective fusion of the palatine shelves results in ___
Cleft palate
____ cartilage forms the stapes, styloid process, stylohyoid ligament, and lesser horn of hyoid
Reichart’s
Branchial arch 1 is innervated by what cranial nerve?
CN V
____ cells form dorsal root ganglion
Neural crest cells
What percent of all clefts are combined cleft lip/patate?
45%
Branchial arch 2 is innervated by what cranial nerve?
CN VII
What percent of all clefts are isolated cleft palate?
30%
____ are derivatives of the intermediate mesoderm
Urogenital system
Mitotic cleavage of zygote forms _____
blastomeres
mesothelial membranes that cover the peritoneal, pleural and pericardial cavities are derivatives of ____ mesoderm
parietal mesoderm
___ formed from ectodermal cells derived from the primitive node. The cells then migrate within the mesodermal layer to their appropriate midline position;
functions as a primitive axial skeleton for the embryo, establishing symmetry and polarity of development
and induction of the somites
Notocord
During the 3rd week of development, the bilaminar embryonic disc is characterized by formation of what 3 things?
Primitive streak, notochord, and neural tube
_____ mesoderm is separated into a parietal and visceral layer
Lateral plate mesoderm
____ are derivates of the paraxial mesoderm
Somites
What is the stage of human development called from 3-8 weeks?
Embryonic period
The 2nd branchial pouch gives rise to _____
palatine tonsils
GI tract epithelium and associated glands are derivatives of the ______
endoderm
Methylmercury and polychlorinated biphenyls are _____ that are known teratogens involved in congenital malformations
Chemicals
______ is a condition where the spinal tube doesn’t form all the way at the bottom
Spina bifida
_____ develops at line of fusion between palatine shelves and primary plate
Nasopalatine Duct Cyst
Sensory to the anterior 2/3 (nerve)
Trigeminal (C-V)
The 3rd branchial pouch gives rise to ______
inferior parathyroids/thymus
____ are the precursors of the vertebral column, ribs, associated back muscles and overlying dermis
Somites
Sensory to the posterior 1/3 (nerve)
Glossopharyngeal (C-IX)
____ is an extrusion of neural tissue plus all 3 meninges
Meningomyocele
Greater than or equal to 32 blastomeres is called a ____
morula
What are the 3 embryonic cavities?
Amniotic, yolk sac, and chorionic
Epidermis, hair, and nails, epithelium of the oral and nasal cavities and paranasal sinuses, salivary and endocrine glands, nervous system, and tooth enamel are derivatives of _____
ecto derm
Branchial arch 3 and 4 give rise to _____ (structure)
Hypobranchial eminence
forms the thin serous membranes that cover individual organs are derivatives of the ____ mesoderm
Visceral mesoderm
Fusion of the medial nasal and maxillary processes occurs when during gestation
5-6 weeks
Odontoblasts, truncoconal septum, pharyngeal arch cartilages, connective tissue surrounding eye pupillary and ciliary muscles, cranial nerve ganglia, dermis and hypodermis of face and neck, glial cells, schwann cells, arachnoid and pia mater, enteric ganglia, melanocytes, preaortic ganglia, adrenal medulla, dorsal root ganglia are all derivatives of _____
Neural crest cells
The 1st branchial groove gives rise to _____
external auditory canal
Fertilization of ovum yields ______
zygote
Cervical sinus remains past ____ week
7th week
Heuser’s membrane will form the internal lining of the blastocyst cavity - now called the _______
yolk sac
