Embryology [Repro] Flashcards
(221 cards)
1
Q
Where is the sonic hedgehog gene expressed?
A
Base of limbs in zone of polarizing activity
2
Q
Where is the Wnt-7 gene expressed?
A
Apical ectodermal ridge (distal end of limb bud)
3
Q
Where is the FGF gene expressed?
A
Apical ectodermal ridge (distal end of limb bud)
4
Q
Sonic hedgehog gene is involved with patterning of which body axis?
A
Anterior-posterior
5
Q
Wnt-7 gene is involved with patterning of which body axis?
A
Dorsal-ventral
6
Q
What processes are directed by Hox genes?
A
Segmentation of embryo in cranial-caudal axis
7
Q
What kinds of defects are caused by Hox mutations?
A
Appendages in wrong places
8
Q
What is the effect of the FGF gene?
A
Stimulates mitosis of underlying mesoderm, lengthening of limbs
9
Q
What defines “Day 0” of embryogenesis?
A
Fertilization of egg by sperm
10
Q
The embryo implants and begins secreting hCG during […] of embryogenesis.
A
The embryo implants and begins secreting hCG during week 1 of embryogenesis.
11
Q
The embryo develops into a bilaminar disk by […] of embryogenesis.
A
The embryo develops into a bilaminar disk by week two of embryogenesis.
[2 weeks = 2 layers]
12
Q
The embryo develops into three layer during […] of embryogenesis.
A
The embryo develops into three layer during week three of embryogenesis.
[3 weeks = 3 layers]
13
Q
The primitive streak, notochord, mesoderm, and neural plate form during week […] of embryogenesis.
A
The primitive streak, notochord, mesoderm, and neural plate form during week 3 of embryogenesis.
14
Q
Organogenesis occurs during weeks […] of embryogenesis.
A
Organogenesis occurs during weeks 3-8 of embryogenesis.
15
Q
Growing embryos are most susceptible to teratogens during […] of embryogenesis.
A
Growing embryos are most susceptible to teratogens during weeks 3-8 i.e. the embryonic period of embryogenesis.
16
Q
The heart begins to beat during […] of embryogenesis.
A
The heart begins to beat during week 4 of embryogenesis.
17
Q
The limb buds begin to form during […] of embryogenesis.
A
The limb buds begin to form during week 4 of embryogenesis.
[4 weeks = 4 limbs]
18
Q
The fetal period begins at […] of embryogenesis.
A
The fetal period begins at week 8 of embryogenesis.
19
Q
Fetal movement is first observed during week […] of embryogenesis.
A
Fetal movement is first observed during week 8 of embryogenesis.
20
Q
Genitalia become visibly different by […] of embryogenesis.
A
Genitalia become visibly different by week 10 of embryogenesis.
21
Q
The three germ layers are […].
A
The three germ layers are endoderm, mesoderm, and ectoderm.
22
Q
What process establishes the embryonal germ layers?
A
Gastrulation
23
Q
Implantation usually occurs near […] of embryogenesis.
A
Implantation usually occurs near day 6 of embryogenesis.
24
Q
The three divisions of the ectoderm are […].
A
The three divisions of the ectoderm are surface ectoderm, neuroectoderm, and neural crest.
25
The adenohypophysis derives from what germ layer?
Surface ectoderm
26
The Rathke's pouch derives from what germ layer?
Surface ectoderm
27
The lens of the eye derives from what germ layer?
Surface ectoderm
28
The epithelial linings of oral cavity derives from what germ layer?
Surface ectoderm
29
The sensory organs of the ear derives from what germ layer?
Surface ectoderm
30
The olfactory epithelium derives from what germ layer?
Surface ectoderm
31
The epidermis derives from what germ layer?
Surface ectoderm
32
The anal canal BELOW the pectinate line derives from what germ layer?
Surface ectoderm
33
The parotid, sweat, and mammary glands derives from what germ layer?
Surface ectoderm
34
The neurohypophysis derives from what germ layer?
Neuroectoderm
35
The pineal gland derives from what germ layer?
Neuroectoderm
36
The retina derives from what germ layer?
Neuroectoderm
37
The optic nerve derives from what germ layer?
Neuroectoderm
38
The spinal cord derives from what germ layer?
Neuroectoderm
39
The dorsal root ganglia derives from what germ layer?
Neural crest
40
The cranial nerves derives from what germ layer?
Neural crest
41
The celiac ganglion derives from what germ layer?
Neural crest
42
The autonomic nervous system derives from what germ layer?
Neural crest
43
The melanocytes derives from what germ layer?
Neural crest
44
The chromaffin cells of adrenal medulla derives from what germ layer?
Neural crest
45
The parafollicular cells (C-cells) of thyroid derives from what germ layer?
Neural crest
46
The pia mater derives from what germ layer?
Neural crest
47
The arachnoid mater derives from what germ layer?
Neural crest
48
The bones of the skull derives from what germ layer?
Neural crest
49
The odontoblasts derives from what germ layer?
Neural crest
50
The aorticopulmonary septum derives from what germ layer?
Neural crest
51
The muscle derives from what germ layer?
Mesoderm
52
The bone derives from what germ layer?
Mesoderm
53
The connective tissue derives from what germ layer?
Mesoderm
54
The serous linings of body cavities derives from what germ layer?
Mesoderm
55
The spleen derives from what germ layer?
Mesoderm
56
The cardiovascular structures derives from what germ layer?
Mesoderm
57
The lymphatics derives from what germ layer?
Mesoderm
58
The blood derives from what germ layer?
Mesoderm
59
The wall of gut tube derives from what germ layer?
Mesoderm
60
The wall of bladder derives from what germ layer?
Mesoderm
61
The urethra derives from what germ layer?
Mesoderm
62
The vagina derives from what germ layer?
Mesoderm
63
The kidneys derives from what germ layer?
Mesoderm
64
The adrenal cortex derives from what germ layer?
Mesoderm
65
The dermis derives from what germ layer?
Mesoderm
66
The gonads (ovaries and testes) derives from what germ layer?
Mesoderm
67
The nucleus pulposus derives from what germ layer?
Mesoderm (remnant of notochord)
68
The gut tube epithelium derives from what germ layer?
Endoderm
69
The lungs derives from what germ layer?
Endoderm
70
The liver derives from what germ layer?
Endoderm
71
The gallbladder derives from what germ layer?
Endoderm
72
The pancreas derives from what germ layer?
Endoderm
73
The eustachian tube derives from what germ layer?
Endoderm
74
The thymus derives from what germ layer?
Endoderm
75
The parathyroid derives from what germ layer?
Endoderm
76
The follicular cells of thyroid derives from what germ layer?
Endoderm
77
The luminal epithelial derivatives derives from what germ layer?
Endoderm
78
Define agenesis (organogenesis).
Absent organ due to absent primordial tissue
79
Define aplasia (organogenesis).
Absent organ despite present primordial tissue
80
Define deformation (organogenesis).
Extrinsic disruption; occurs after embryonic period
81
Define hypoplasia (organogenesis).
Incomplete organ development; primordial tissue present
82
Define malformation (organogenesis).
Intrinsic disruption; occcurs during embryonic period
83
Before week 3, teratogens tend to exert **[...]** effects on the zygote.
Before week 3, teratogens tend to exert **all-or-none** effects on the zygote.
84
After week 8, teratogens tend to exert **[...]** effects on the fetus.
After week 8, teratogens tend to exert **growth and function** effects on the fetus.
85
The following effects are characteristic of what teratogen: renal damage
ACE inhibitors
86
The following effects are characteristic of what teratogen: absence of digits (and multiple varied anomalies)
Alkylating agents
87
The following effects are characteristic of what teratogen: CN 8 toxicity
Aminoglycosides
88
The following effects are characteristic of what teratogen: neural tube defects, craniofacial defects, fingernail hypoplasia, developmental delay, IUGR
Carbamazepine
89
The following effects are characteristic of what teratogen: vaginal clear cell adenocarcinoma, congenital Mullerian anomalies
Diethylstilbestrol (DES)
90
The following effects are characteristic of what teratogen: neural tube defects
Folate antagonists
91
The following effects are characteristic of what teratogen: Ebstein's anomaly
Lithium
92
What is Ebstein's anomaly?
Atrialized right ventricle
93
The following effects are characteristic of what teratogen: fetal hydantoin syndrome
Phenytoin
94
Diagnose: in newborn: microcephaly, dysmorphic craniofacial features, hypoplastic nails and distal phalanges, cardiac defects, IUGR, mental retardation
Fetal hydantoin syndrome
95
The following effects are characteristic of what teratogen: discolored teeth
Tetracyclines
96
The following effects are characteristic of what teratogen: limb defects (flipper limbs)
Thalidomide
97
The following effects are characteristic of what teratogen: neural tube defects (inhibition of maternal folate absorption)
Valproate
98
The following effects are characteristic of what teratogen: bone deformities, fetal hemmorhage, abortion, ophthalmologic abnormalities
Warfarin
99
The following effects are characteristic of what teratogen: fetal alcohol syndrome
Alcohol
100
The following effects are characteristic of what teratogen: abnormal fetal development, placental abruption, fetal stimulant addiction
Cocaine
101
The following effects are characteristic of what teratogen: preterm labor, placental problems, IUGR, ADHD
Tobacco
102
The following effects are characteristic of what teratogen: congenital goiter
Iodide (lack)
103
The following effects are characteristic of what teratogen: congenital hypothyroidism
Iodide (excess)
104
The following effects are characteristic of what teratogen: caudal regression syndrome, congenital heart defects, neural tube defects
Maternal diabetes
105
The following effects are characteristic of what teratogen: spontaneous abortion, cleft palate, cardiac abnormalities
Vitamin A (excess)
106
The following effects are characteristic of what teratogen: microcephaly, mental retardation
X-rays
107
What is the etiology of fetal alcohol syndrome?
Maternal consumption of alcohol during pregnancy
108
Diagnose: mental retardation, pre- and post-natal developmental retardation, microcephaly, holoprosencephaly, facial abnormalities, limb dislocation, heart and lung fistula
Fetal alcohol syndrome
109
What is the leading cause of congenital malformations in the US?
Fetal alcohol syndrome
110
Dizygotic twins arise from **[...]** egg(s) and **[...]** sperm.
Dizygotic twins arise from **2** egg(s) and **2** sperm.
111
Monozygotic twins arise from **[...]** egg and **[...]** sperm.
Monozygotic twins arise from **1** egg and **1** sperm.
112
What percent of twins are monozygotic?
20%
113
What percent of twins are dizygotic?
80%
114
How many chorions and amnions develop when a zygote splits between Day 0-4?
2 chorions, 2 amnions
115
How many chorions and amnions develop when a zygote splits between Day 4-8?
1 chorion, 2 amnions
116
How many chorions and amnions develop when a zygote splits between Day 8-12?
1 chorion, 1 amnion
117
How many chorions and amnions develop when a zygote splits after Day 12?
1 chorion, 1 amnion, conjoined twins
118
What is the purpose of the placenta?
Primary site of nutrient and gas exchange between fetus and mother
119
List the fetal components of the placenta.
Cytotrophoblast, syncytiotrophoblast
120
List the materal components of the placenta.
Dedicua basalis
121
The cytotrophoblast forms the **[...]** layer of the chorionic villi.
The cytotrophoblast forms the **inner** layer of the chorionic villi.
122
The syncytiotrophoblast forms the **[...]** layer of the chorionic villi.
The syncytiotrophoblast forms the **outer** layer of the chorionic villi.
123
What part of the placenta secretes hCG?
Syncytiotrophoblast
124
hCG is structurally similar to what maternal hormone?
LH
125
Identify 1
chorionic villi
126
Identify 2
uterine artery and vein
127
Identify 3
maternal blood in intervillus space
128
Identify 4
uterus
129
Identify 5
placenta
130
Identify 6
umbilical artery
131
Identify 7
umbilical vein
132
Identify 8
amnion
133
Identify 9
chorion
134
Identify 11
amniotic fluid
135
There are **[...]** umbilical arteries and **[...]** umbilican veins in a normal umbilical cord.
There are **2** umbilical arteries and **1** umbilican veins in a normal umbilical cord.
136
The umbilical vein drains into the **[...]** via the **[...]**.
The umbilical vein drains into the **IVC** via the **ductus venosus**.
137
The umbilical arteries carry **[...]** blood from the **[...]** arteries to the **[...]**.
The umbilical arteries carry **deoxygenated blood** from the **fetal internal illiac arteries** to the **placenta**.
138
The umbilical vein carries **[...]** blood from the **[...]** to the **[...]**.
The umbilical vein carries **oxygenated blood** from the **placenta** to the **fetus**.
139
Umbilical arteries and veins are derived from the **[...]**.
Umbilical arteries and veins are derived from the **allantois**.
140
Diagnose: urine discharge from umbilicus
Patent urachus
141
What are the characteristic signs and symptoms of vesicourachal diverticulum?
Outpouching of bladder into umbilicus
142
Diagnose: meconium discharge from umbilicus
Vitelline fistula
143
What is the etiology of Meckel's diverticulum?
Failure of vitelline duct to close
144
Diagnose: in newborn: melena, periumbilical pain, ulcer
Meckel's diverticulum
145
What is the etiology of vesicourachal diverticulum?
Failure of urachus to obliterate
146
What is the etiology of patent urachus?
Failure of urachus to obliterate
147
What is the etiology of vitelline fistula?
Failure of vitelline duct to close
148
The 1st aortic arch forms the **[...]** artery.
The 1st aortic arch forms the **maxillary** artery.
## Footnote
[**1**st arch is **max**imal]
149
The 2nd aortic arch forms the **[...]** artery.
The 2nd aortic arch forms the **stapedial and hyoid** artery.
## Footnote
[**S**econd = **S**tapedial]
150
The 3rd aortic arch forms the **[...]** artery.
The 3rd aortic arch forms the **common and internal carotid** artery.
151
The 4th aortic arch forms the **[...]** artery.
The 4th aortic arch forms the adult **aortic arch and subclavian** artery.
## Footnote
[**4**th arch (**4** limbs) = systemic]
152
The 6th aortic arch forms the **[...]** artery and **[...]**.
The 6th aortic arch forms the **pulmonary artery** and **ductus arteriosus**.
153
The 5th aortic arch forms the **[...]** artery.
The 5th aortic arch forms the **nothing** - it degenerates artery.
154
The branchial (or pharyngeal) apparatus is composed of [...].
The branchial (or pharyngeal) apparatus is composed of clefts, arches, and pouches.
155
The branchial clefts derives from what germ layer?
ectoderm
156
The branchial arches derives from what germ layer?
mesoderm, neural crest ectoderm
157
The branchial pouches derives from what germ layer?
endoderm
158
The external auditory meatus derives from what branchial precursor?
1st cleft
159
What is the etiology of persistent cervical sinus?
Abnormal persistence of branchial cleft cyst
160
What are the characteristic signs and symptoms of persistent cervical sinus?
Cyst in lateral neck
161
The Meckel's cartilage derives from what branchial precursor?
1st arch
162
The mandible derives from what branchial precursor?
1st arch
163
The malleus derives from what branchial precursor?
1st arch
164
The manibular ligament derives from what branchial precursor?
1st arch
165
The muscles of mastication derives from what branchial precursor?
1st arch
166
The mylohoid derives from what branchial precursor?
1st arch
167
The tensor tympani derives from what branchial precursor?
1st arch
168
The tensor veli palantini derives from what branchial precursor?
1st arch
169
The CN 5.2, 5.3 derives from what branchial precursor?
1st arch
170
What is the etiology of Treacher Collins syndrome?
1st arch neural crest fails to migrate
171
What are the characteristic signs and symptoms of Treacher Collins syndrome?
mandibular hypoplasia, facial abnormalities
172
The Reichert's cartilage derives from what branchial precursor?
2nd arch
173
The stapes derives from what branchial precursor?
2nd arch
174
The incus derives from what branchial precursor?
1st arch
175
The styloid process derives from what branchial precursor?
2nd arch
176
The stylohyoid ligament derives from what branchial precursor?
2nd arch
177
The lesser horn of hyoid derives from what branchial precursor?
2nd arch
178
The muscles of facial expression derives from what branchial precursor?
2nd arch
179
The stapedius derives from what branchial precursor?
2nd arch
180
The stylohyoid derives from what branchial precursor?
2nd arch
181
The CN 7 derives from what branchial precursor?
2nd arch
182
The greater horn of hyoid derives from what branchial precursor?
3rd arch
183
The stylopharyngeus derives from what branchial precursor?
3rd arch
184
What is the etiology of congenital pharyngo-cutaneous fistula?
Persistence of 3rd branchial cleft and pouch
185
Diagnose: fistula between tonsillar area, cleft in neck
Congenital pharyngo-cutaneous fistula
186
The thyroid catrilage derives from what branchial precursor?
4th-6th arches
187
The cricoid cartilage derives from what branchial precursor?
4th-6th arches
188
The arytenoid cartilages derives from what branchial precursor?
4th-6th arches
189
The corniculate derives from what branchial precursor?
4th-6th arches
190
The cuneform derives from what branchial precursor?
4th-6th arches
191
The pharyngeal constrictor muscles derives from what branchial precursor?
4th arch
192
The cricothyroid muscle derives from what branchial precursor?
4th arch
193
The levator veli palantini derives from what branchial precursor?
4th arch
194
The intrinsic muscles of larynx (except cricothyroid) derives from what branchial precursor?
6th arch
195
The CN 10 - superior laryngel branch derives from what branchial precursor?
4th arch
196
The CN 10 - recurrent laryngeal branch derives from what branchial precursor?
6th arch
197
The anterior 2/3 of tongue derives from what branchial precursor?
1st arch
198
The posterior 1/3 of tongue derives from what branchial precursor?
3rd and 4th arches
199
The middle ear cavity derives from what branchial precursor?
1st pouch
200
The eustachian tube derives from what branchial precursor?
1st pouch
201
The mastoid air cells derives from what branchial precursor?
1st pouch
202
The endoderm lined structures of the ear derives from what branchial precursor?
1st pouch
203
The epithelial lining of palantine tonsil derives from what branchial precursor?
2nd pouch
204
The thymus derives from what branchial precursor?
3rd pouch
205
The inferior parathyroids derives from what branchial precursor?
3rd pouch
206
The superior parathyroids derives from what branchial precursor?
4th pouch
207
What is the etiology of cleft lip?
Failure of fusion of maxillary and medial nasal processes (primary palate)
208
What is the etiology of cleft palate?
Failure of fusion of lateral palantine processes, nasal septum, and median palantine processes (secondary palate)
209
What is the etiology of bicornate uterus?
Incomplete fusion of paramesonephric ducts
210
What are the characteristic signs and symptoms of bicornate uterus?
Urinary tract abnormalities and miscarriages
211
Diagnose: male internal genitalia, ambiguous external genitalia until puberty
5α-reductase deficiency
212
What is the etiology of hypospadias?
Failure of closure of urethral folds
213
What is the physical defect in hypospadias?
Abnormal opening of penile urethra on ventral side of penis
214
What are some possible complications of hypospadias?
UTIs
215
What is the etiology of epispadias?
Faulty positioning of genital tubercle
216
What is the physical defect in epispadias?
Abnormal opening of penile urethra on dorsal aspect of penis
217
What are some possible complications of epispadias?
Exstrophy of the bladder
218
What is the inheritance pattern in 5α-reductase deficiency?
AR
219
What is the pathogenesis of 5α-reductase deficiency?
Inability to convert testosterone to DHT
220
What are the characteristic lab findings in 5α-reductase deficiency?
Normal: testosterone, estrogen
Increased: LH (or normal)
221
What volume defines oligohydramnios?
\> 0.5 L amnionic fluid
