Decks Embryology Flashcards
tongue develops begins development in what week
4th
3 major salivary glands begin development in what weeks
6-8th
1st salivary gland to develop and time
parotid 6th week
2nd salivary gland to develop and time
submandibular gland late 6th week
3rd salivary gland to develop and time
sublingual gland 8th week
tongue appears in the 4th week first as how many swellings
2 lateral and one medial swellings.
2 lateral and one medial swellings originate from _ arch
1st branchial arch
the medial swelling of the tongue that forms the anterior 2/3 of the tongue (body of the tongue) is called the
tuberculum impar
the other median swelling is the ___
copula
copula is formed by mesoderm of what arches
2-4th arches
the 2 lateral tongue swellings overgrow the tuberculum impar and merge together to form the
anterior 2/3 of the tongue
the posterior 3rd of the tongue originates from what arches
2, 3, 4th
the extreme posterior part of the tongue what arch
4th
the anterior 2/3 of the tongue is separated by the posterior 1/3 by the
terminal sulcus = V shaped groove
foramen cecum is remnant of the proximal end of the
thyroglossal duct
branchial clefts are _ origin
ectoderm (think eCtoderm)
the branchial pouches are _ origin
endoderm
how many branchial arches and what shape
6 U shaped
core of branchial arches is
mesenchyme formed from mesoderm and neural crest cells that migrate to the neck
parotid gland is derived from
ectoderm
submandibular and sublingual glands derived from
endoderm
which cartilages of branchial arches are derived from neural crest cells?
1st and 2nd
which cartilages of branchial arches are derived from mesoderm
4-6th
first branchial arch = _ cartilage derivatives
Meckel’s cartilage = ossified to form the malleus and incus of middle ear, sphenomandibular ligament and parts of the sphenoid bone
bony mandible forms from _ ossification
intramembranous
most of Meckel’s cartilage disappears ONLY SOME of Meckel’s cartilage makes a contribution to it. its fate is DISSOLUTION WITH MINOR CONTRIBUTIONS TO OSSIFICATION
mandibulofacial dysostosis development defect affecting the derivatives of _ arch
1st = micrognathia (small lower jaw), malar (zygomatic hypoplasia), deformed lower rim of the orbit and ear. neural crest cells failed to migrate into arch
second arch derivatives
reichert’s cartilage = ossified to form stapes of middle ear, styloid process of temporal bone, the stylohyoid ligament, lesser cornu of the hyoid and upper half of body of hyoid
which arches closely related to middle ear development
1 + 2
third arch cartilage form the
greater cornu of hyoid bone and lower half of the body of the hyoid
4-6th arches cartilage
laryngeal cartilages of the larynx (thyroid, cricoid, arytenoid, corniculate, cuneiform)
cleft lip failure of fusion of
maxillary process and 2 medial nasal processes
maxillary and mandibular processes fuse on the sides to form the
labial commissures (corners of the mouth)
mandible forms from fusion of the right and left mandibular process in what week?
4th week.
the _ is the first portion of the face to form AFTER the creation of the stomodeum
mandible
maxilla formed by merging of the
2 maxillary processes of 1st branchial arch.
maxilla also forms the
upper check regions and most of upper lip
frontonasal process/prominence forms in what week
4th
frontonasal process gives rise to
forehead, bridge of nose, primary palate, nasal septum and medial nasal processes
nasal placodes in the anterior portion of he frontonasal. what part forms the alae of the nose
alae means sides- lateral nasal processes
philtrum, portion of upper lip, and middle portion of nose form from fusion of the
medial nasal processes
mandibular symphysis
ridge in midline on surface of the bony mandible where mandible is formed by fusion of the mandibular processes
most of upper lip formed by
maxillary process
palatine tonsils form from
2nd pharyngeal POUCH (remember it is inside = endodermal origin)
inferior parathyroid form from
3rd pharyngeal pouch
thymus forms from
3rd pharyngeal pouch
superior parathyroids form from
4th pharyngeal pouch
ultimobranchial bodies give rise to the _ cells of the thyroid
C
ultimobranchial bodies arise from the
5th branchial pouch (or 4th in some books so look for either answer)
tympanic membrane and cavity forms from the _ pouch
1st
auditory tube and mastoid antrum form from the
1st pouch
external auditory meatus formed from the
fist pharyngeal CLEFT (OUTSIDE)
Digeorge syndrome = what’s been affected
congenital malformation caused by underdevelopment of 3rd and 4th POUCHES leading to hypoplasia or absence of parathyroid glands = congenital heart defects and compromised immunity
thyroid gland identifiable in what week
4th along with tongue
first development of face development in the 4th wk is
disitntegration of the oropharyngeal membrane
initial site of the thyroid gland is bw the
copula and tuberculum impar (foramen secum)
thyroid gland descend through the thyroglossal duct to it permanent location below/above the thyroid cartilage?
below
palate is completed during what week
12th
primary palate forms first in what week
5th
intermaxillary segment is the result of the fusion of ? what does it form
2 medial nasal processes and frontonasal processes = forms the primary palate
secondary palate forms in what week
6th week (same as parotid gland time)
secondary palate forms from
two palatal shelves aka lateral palatine processes of the maxillary process
secondary palate is the
posterior 2/3 of the hard palate = canines and posterior teeth
the primary palate forms first, then the second, then they both meet and fuse - completion of palate in what week
12
nasal cavity formed by
nasal pits from the nasal placodes
ligamentum teres in the adult comes from _ in the fetus
umbilical vein
medial umbilical ligaments in the adult comes from _ in the fetus
umbilical arteries
ligamentum arteriosum in the adult comes from _ in the fetus
ductus arteriosus
ligamentum venosus in the adult comes from _ in the fetus
ductus venosus
urachus in the adult comes from _ in the fetus
allantios
nucleus pulposus in the adult comes from _ in the fetus
notochord