NBDE: ANATOMICAL SCIENCES: Embryology Flashcards
(150 cards)
1
Q
During the 4th week of embryonic development the tongue appears in the form of 2 lateral lingual swelling and one medial swelling, the so-called: foramen cecum sulcus terminalis tuberculum impar epiglottic swelling
A
tuberculum impar
2
Q
the three swellings of the tongue (2 lateral and 1 medial tuberculum impar) seen in the 4th week of development originate from the _
A
1st branchial arch
3
Q
A second median swelling called the copula is formed by mesoderm of
A
2nd, 3rd, and 4th branchial arches
4
Q
the lateral lingual tongue swellings overgrow the tuberculum impar and merge with each other, forming the
A
anterior 2/3 of the tongue
5
Q
the posterior third of the tongue originates from the
A
2nd, 3rd and 4th pharyngeal arches
6
Q
the extreme posterior part of the tongue is derived from the
A
4th pharyngeal arch
7
Q
the anterior two thrids of the tongue are separated from the posterior 3rd by a V-shaped groove called the
A
terminal sulcus
8
Q
the foramen cecum, the remnant of the proximal end of the __ is located at the apex of the terminal sulcus
A
thyroglossal duct
9
Q
the _ are stacked _ swellings of tissue that appear inferior to the stomodeum (primitive mouth) during the 4th week of development
A
branchial arches
bilateral swellings
10
Q
the branchial arches are _ pairs of _ shaped bars with a core _ which is formed by mesoderm and neural crest cells that migrate to the neck region
A
six pairs of U shaped bars
core mesenchyme
11
Q
the branchial arhes are covered externally by ectodermal lined __
A
branchial clefts
12
Q
the branchial arches are internally lined by
A
endodermal lined branchial pouches
13
Q
the branchial arches support the
A
lateral walls of the primitive pharynx
14
Q
Bifid tongue is the result of __
A
lack of fusion of the distal tongue buds (lateral swellings) = common in south African infants
15
Q
most tongue muscles develop from myoblasts originating in the _
A
occipital somites
16
Q
the musculature is innervated by the _ nerve
A
hypoglossal
17
Q
the _ branchial arch is so rudimentary (immature, undeveloped) that they are absent in humans or are included with the 4th branchial arches
A
5th
18
Q
in what weeks of development do the major salivary glands begin as epithelial proliferations or buds from the ectodermal lining of the primitive mouth
A
6-8th week in utero
19
Q
the first salivary gland to form in the 6th week are the
A
parotic glands
20
Q
after the parotid gland appears in the 6th week we see which gland later in the same week
A
submandibular glands
21
Q
what salivary glands do we see in the 8th week
A
sublingual glands
22
Q
- The parotid glands are derived from which germ layer?
2. The submandibular and sublingual glands are derived from which germ layer?
A
- parotid is ectoderm
2. submandibular and sublingual glands are endoderm
23
Q
branchial (arches, pouches, and clefts) are aka
A
pharyngeal arches, pouches, and clefts
24
Q
the body of the tongue develops from the
A
lateral lingual swellings and the tuberculum impar of the 1st arch growing together
25
the root of the tongue develops from the _ of the _ arch
copula of the 3rd arch
26
the epiglottis develops from the _ of the _ arch
epiglottal swelling of 4th arch
27
the arches are covered externally by a ectodermal __, internally by endodermal __, and the arches are made of _
cleft = ectoderm (outer)
pharyngeal/branchial arches (the middle) = mesenchyme from mesoderm neural crest
the inner = pouches = endoderm
28
each pharyngeal arch develops its own
artery, nerve, muscle element and cartilage (skeletal) elemnt of the head and neck
29
clefts aka
grooves
30
the ___ gives rise to the middle ear cavity, Eustachian tube, palantine tonsil, parathyroid glands, thymus, and ultimobranchial bodies
endoderm of the pharyngeal pouches
31
the _ gives rise to the external auditory meatus
pharyngeal clefts/grooves
32
T/F the cartilage of the 1st and 2nd branchial arches are derived from mesoderm
F = cartilage of the 1st and 2nd branchial arches are derived from neural crest cells
33
T/F the cartilage of the 4th and 6th branchial arches are derived from neural crest cells
F: the cartilage of the 4th and 6th branchial arches are derived from mesoderm
34
the branchial arches cartilage, nerve, vascular, and muscular components within the mesodermal core are elements of the neural crest except for the cartilages of the _ which are derived from mesoderm
arches 4-6
35
Meckel's cartilage is _ arch cartilage
1st arch
36
what are the derivatives of the first arch
mandible, maxilla, Meckel's cartilage
37
Meckel's cartilage is closely related to the developing __ and becomes ossified to form what 4 things
incus, malleus of middle ear, sphenomandibular ligament and parts of the sphenoid bone
38
most of the cartilage of the cartilage of the 1st arch disappears as the mandible forms by _ ossification. Only some of Meckel's cartilage makes a contribution.
intramembranous
39
__ fate is dissolution with minor contributions to ossification
the first arch (meckel's cartilage)
40
Mandibulofacial Dysostosis = developmental defect affecting the derivatives of the _ branchial arch.
1st
41
Mandibulofacial Dysostosis clinical evidence?
patient will have micrognathia (small lower jaw), malar (zygomatic) hypoplasia, deformity of the lower rim of the orbit and malformed external ear. = indicate problem with neural crest cell migration of the 1st branchial arch
42
Reichert's cartilage is the _ arch
2nd
43
Merkel's cartilage is the _ arch
1st
44
Reichert's cartilage is related to the developing _
middle ear.
45
Reichert's cartilage becomes ossified to form the _
stapes of middle ear, styloid process of temporal bone, the sylohyoid ligamne, the lesser cornu (horn) of the hyoid, and the upper part of the hyoid bone
46
the _ arch cartilage ossifies into the lower part of the body of the hyoid bone and greater (corneu) horns of the hyoid
third
47
the _ arches cartilage are the laryngeal cartilages
laryngeal: form the cartilages of the larynx: thyroid, cricoid, arytenoid, corniculate, and cuneiform)
48
failure of fusion of what leads to cleft lip:
1. frontonasal process + lateral nasal process
2. maxillary process and medial nasal process
3. lateral nasal process and medial nasal process
4. maxillary process and lateral nasal process
2. maxillary process and medial nasal process
49
in the young embryo the stomodeum (primitive mouth) is temporarily closed by the
buccopharyngeal membrane
50
although 6 pharyngeal arches develop, the _ arch degenerates and the 6th arch does not form an external elevation
degenerates
51
the _ pharyngeal arch has a maxillary and mandibular prominence
first
52
each of the first 4 pharyngeal arches contain cartilage that will develop into the
facial bones and laryngeal cartilages
53
the maxilla develops from mesenchymal condensation that undergoies intramembranous ossification. the developing bone eventually replaces the embryonic max cartilages. Bone growth moves the maxilla which direction
down and forward.
54
the mandible forms from a condensation of mesenchyme lateral to _ during the 6th week of development
Meckel's cartilage
55
at 7weeks the mesenchyme of the mandible undergoes _ ossification where the inferior alveolar nerve divides into the incisive and mental branches. Bone formation spreads rapidly towards the midline but remains separate until shortly
after birth
56
Meckel's cartilage eventually degenerates except for _
the malleus and incus ossicles of the middle ear.
57
growth of most of the mandible is via intramembranous ossification. What 2 parts of the mandible involves endochondral ossification?
ramus and condyle
58
the ultimobranchial body is incorporated into the
thyroid gland = gives rise to the parafollicular od C-cells of the thyroid gland
59
the palatine tonsils come from which pharyngeal pouch
2nd
60
the inferior parathyroid glands and thymus comes from which pharyngeal pouch
3rd
61
the superior parathyroid glands and ultimobranchial bodies comes from which pharyngeal pouch
4th
62
the thyroid gland originates from an invagination in the pharyngeal epithelium at the
foramen cecum
63
the invagination in the pharyngeal epithelium at the foramen cecum initially forms the __ which closes after the thyroid tissue migrates to the trachea below the larynx
thryoglossal duct
64
during development of the lips and palate, the medial growth of the two _ of the 1st arch leads to their fusion into the intermaxillary segment which forms the philtrum of the upper lip, and the part of the maxilla that holds the 4 upper incisors and the triangular primary palate together.
maxillary prominence aka processes
65
1. the _ contribute to the MIDDLE of the upper lip.
| 2. the _ contribute to the SIDES of the upper lip
1. two medial nasal processes
| 2. maxillary processes
66
fusion of the _ and _ form the upper lip in the 6th week- when the grooves bw the processes are obliterated
maxillary processes and two medial nasal processes
67
defects of the lips and palate result from a failure of
embryonic tissue to fuse
68
the maxillary processes on each side of the developing face and the mandibular arch fuse to form the
labial commisures aka corners of the mouth
69
cleft lip is mostly in M/F
80% males
70
isolated cleft palate occurs more often in M/F
females (67%)
71
what drugs taken during pregnancy increase the risk of cleft palate
anti-convulsants ex phenobarbital
72
pharyngeal arch _ mesoderm develops into the muscles of mastication
1
73
pharyngeal arch _ mesoderm develops into the muscles of facial expression
2
74
pharyngeal arches _ + _ mesoderm develops into the strap muscles of the neck
3 and 4
75
pharyngeal arch _ develops into trigeminal nerve for mastication
1
76
pharyngeal arch _ develops into facial nerve for facial expression
VII
77
after the stomodeum is formed two bulges of tissue appear inferior to the primitive mouth, the _ of the _ arch
2 large mandibular process
| 1st arch
78
the mandible forms as a result of the fusion of the
R and L mandibular processes
79
the _ is the first portion of the face to form after the stomodeum
mandible
80
the maxilla is formed primarily by the merging of the two smaller _ of the _branchial arch
maxillary processes of the first branchial arch
81
the maxillary processes also form the
upper cheek regions and most the upper lip
82
the forehead, bridge of nose, primary palate, nasal septum and all structures related to the medial nasal processes develops from the
frontonasal process (prominenc)
83
the nasal placodes form in the anterior portion of the frontonasal process. they develop into
olfactory cells for sensation of smell
84
the middle portion of the tissue growing around the nasal placodes appears as two crescent shaped swelling = medial nasal processes, which fuse to form the
middle portion of the nose from the root to the apex and the center portion of the upper lip and philtrum region
85
on the outer portion of the nasal placodes are two other crescent shaped swelling, the lateral nasal processes which will form the _
alae = sides of the nose
86
fusion of the lateral nasal, maxillary, and medial nasal processes forms the
nares (nostrils)
87
partial unilateral and bilateral cleft of the lip results from failure of the _ and _ to fuse
maxillary and medial nasal processes
88
clefts involving the hard and soft palate are the result of a lack of fusion among the
lateral palatal process, the primary palate and the nasal septum = failure of fusion of palatine shelves will lead to cleft palate
89
during the 4th week of embryonic development the 1st branchial arch divides into:
a. 2 medial nasal processes
b. the mandibular and maxillary processes
c. 2 lateral nasal process
d. the lateral and medial nasal processes
b. the mandibular and maxillary processes aka prominences
90
the branchial arches are stacked ___ swellings that appear inferior or superior to the stomodeum during the _ week of embryonic development
bilateral
inferior to primitive mouth
4th week
91
the branchial aches are 6pairs of U shaped bars with a core _ which is formed by mesoderm and neural crest cells that migrate to the neck region
mesenchyme
92
the branchial arches are covered externally by ectodermal _
clefts
93
the arches are bordered medially by the pharynx, which is lined by
endoderm.
94
medially each branchial arch is separated by a
pharyngeal pouch
95
the approximation of the ectoderm of the pharyngeal cleft with the endoderm of the pouch forms the
pharyngeal membrane
96
the _ is a faint ridge in midline on the surface of the bony mandible where the mandible is formed by the fusion of the mandibular process
mandibular symphysis
97
the _ form the upper cheek regions and most of the upper lip
maxillary process
98
the 2nd branchial pouch gives rise to:
a. Eustachian tube
b. palatine tonsil
c. middle ear cavity
d. superior PT gland
b. palatine tonsil
remember it is from pouch = P = Palatine
99
4 well defined pairs of pharyngeal pouches develop as endodermal evaginations from the lateral walls lining the
pharynx
100
the _ pouch contributes to the formation of the tympanic membrane, tympanic cavity, mastoid antrum, auditory tube
1st pouch:
| MATT
101
the inferior PT and the thymus gland develop from the _
3rd pouch
P = for Pouch and PT
102
the _ pharyngeal _ develops into the ultimobranchial bodies = gives rise to C cells of the thyroid
5th, pouch
note some books consider the 5th pouch rudimentary and say the 4th pouch develops into ultimobranchial bodies
103
C cells of thyroid secrete
calcitonin
104
the first branchial _ forms the external auditory meatus
cleft
105
Digeorge syndrome is a congenital malformation caused by the underdevelopment of the _ branchial_
3rd and 4th = hypoplasia or absence of PT glands
106
Digeorges patients have _ problems (2)
congenital heart defects and compromised immunity
107
the oral cavity (primitive mouth/stomodeum) appears as a shallow depression in the embryonic surface _
ectoderm
108
the buccopharyngeal (oropharygeal) membrane separates the _ form the_
stomodeum from primitive pharynx
109
the primitive pharynx is the cranial portion of the foregut, the beginning of the future
digestive tract
110
the oral cavity is lined with
oral epithelium derived from ectoderm as a result of embryonic folding
111
the initial site of the _ gland lies bw the copula and the tuberculum impar which is called (foramen cecum)
thyroid gland
112
the thyroid gland descends thru the thyroglossal duct to its permanent location where
below the thyroid cartilage in the neck
113
thyroglossal tract/duct remnants are referred to as
thyroglossal duct cyst
114
the primary palate or medial palatal process is formed by the merging of the frontonasal process w what other processes?
a. lateral nasal processes
b. medial nasal processes
c. maxillary processes
d. mandibular processes
medial nasal processes
115
the palate is formed from two separate embryonic structures, the
primary and secondary palate = completed in 12th week
116
which palate is formed first
primary then secondary then completed
117
the primary palate forms around 5th week. the intermaxillary segment arises as a fusion of
2 medial nasal processes and the frontonasal process
118
the intermaxillary segment gives rise to the
primary palate (the anterior 1/3 of the final palate) anterior to the incisive foramen, contains the maxillary incisors
119
the secondary palate forms in 6th week by the
bilateral maxillary processes giverise to the 2 palatal shelves (lateral palatine processes) which move medially towards eachother and fuse to form the secondary palate =posterior 2/3 of the palate posterior to incisive foramen and includes the soft palate and uvula
120
in the 12th week the palate formation completes by
fusion of primary and secondary palates
121
the _ palate forms from fuse palatal shelves
secondary
has the canines
and posterior teeth)
122
all are derived from first branchial arch except:
a. tensor tympani
b. anterior belly of digastric
c. temporalis
d. masseter
e. levator veli palatini
f. tensor veli palatini
e. levator veli palatini
123
the first arch (mandibular) future nerves and muscles?
trigeminal nerve (V2 and V3) and all the muscles innervated by trigeminal nerve
124
the third arch muscle and nerve?
glossopharyngeal (CN 9) and its muscle: stylopharyngeal
125
4th arch future nerves and muscle
superior laryngeal branch of vagus nerve, most pharyngeal constrictors, levator veli palatini and cricothyroid muscle
126
6th arch future nerves and muscle
reccurent laryngeal branch of vagus nerv: all intrinsic muscles of larynx except cricothyroid
127
spenomalleolar ligament, sphenomandibular ligament, mandible, maxilla, Meckel's cartilage, incus, malleus all from which arch
1st
128
greater cornu and lower part of hyoid from which arch
3rd
129
laryngeal cartilages from which arch
4-6
130
Reichert's cartilage, styloid process, stylohyoid ligament, lesser cornu and upper part of hyoid and stapes from which arch
2
131
the nasal cavities are formed from which embryonic structure
a. stomodeum
b. intermaxillary segment
c. frontonasal process
d. nasal pits
nasal pits
132
the nasolacrimal cord originates from nasolacrimal groove and gives rise to what 2 tissues
lacrimal sac and nasolacrimal duct
133
lateral nasal processes originate from the lateral frontonasal processes and give rise to
nasal alae
134
the medial nasal processes fuse to form the __ which gives rise to the
intermaxillary segment
| anterior portion of maxilla, primary palate
135
the frontonasal process medial to the nasal pits form the medial nasal processes that give rise to
the middle of the nose, philtrum, intermaxillary segment
136
the lower lip, lower face and mandible came from what arch
first arch = mandibular arch
137
the oral cavity proper embryonic origin
stomodeum -ectodermal
138
all are neural crest derived except:
a. melanocytes
b. dorsal root ganglia
c. adrenal medulla
d. autonomic ganglia
e. adrenal cortex
f. schwann cells
f. sensory ganglia of cranial nerves
adrenal cortex is derived from mesoderm
139
hair, nails, epidermis, inner and external ear, lens of eye, parotid, epidermis, adenophypophysis are all _ derivitives
ectoderm
140
neurohypohysis, CNS, oligodendrocytes, astrocytes,pineal gland, retina and optic nerve are all _ derivatives
neuroectoderm
141
which 2 are not from endoderm:
a. lung
b. liver
c. gut tube derivatives
d. pancreas
e. spleen
f. thymus
g. dura mater
h. PT gland
dura mater
| spleen
142
heart, blood, dermis, muscles, vessels, adrenal cortex, dura mater, bone, spleen, kidney and ureter are _ derivative
mesoderm =
Give ME the BBUDD SAcK
b = bone/blood, ureter, dura mater, dermis, Spleen, Adrenal Cortex, Kidneys
143
Gi tract (foregut, midgut, hindgut), lung liver, pancreas, thymus, thyroid, PT, submandibular and sublingual glands, middle ear and auditory tube are _ derivatives
endoderm
give ME the BBUDD SAcK
"EN SSPPELL GATT"
144
nucleus pulposus in the adult is the _ in the fetus
notochord
145
Urachus in the adult is the _ in the fetus
allantios
146
fossa ovalis in the adult is the _ in the fetus
foramen ovale
147
ligamentum venosum in the adult is the _ in the fetus
ductus venosus
148
ligamentum arteriosum in the adult is the _ in the fetus
ductus arteriosus
149
medial umbilical ligaments in the adult is the _ in the fetus
umbilical arteries
150
ligamentum teres
| in the adult is the _ in the fetus
umbilical vein
