Embryo Flashcards
1
Q
alcohol is most teratogenic during which weeks?
A
weeks 3–9
2
Q
first indication of gastrulation in the embryo is formation of the (formed through invagination of the epiblast):
A
primitive streak
week 3
3
Q
what week do we see development of the notochord?
what week is differentiation of the three primary germ layers and the derivative of each layer?
A
both week 3
4
Q
conjoined (siamese) twins is due to incomplete division of:
A
hypoblast (inner cell mass) or 2º fusion
5
Q
remnants of the primitive streak, containing derivatives from all three germ layers, can persist as:
A
sacrococcygeal teratoma
6
Q
- associated with fetal hydrops; can be rapidly fatal in utero or can lead to polyhydramnios and premature delivery
- the high-output cardiac failure is related to “vascular steal” from the high blood flow through the tumor
A
sacrococcygeal teratoma
7
Q
“VACTERL” – mnemonic for mesodermal defects:
A
Vertebral defects Anal atresia Cardiac defects Tracheo-Esophageal fistula Renal defects Limb defects (bone and muscle)
8
Q
caudal dysplasia (e.g., sirenomelia) is due to a defect in which germ layer?
A
mesoderm
9
Q
organ system that begins its morphological development first:
A
CNS
10
Q
principal inductor in neural tube formation:
A
notochord
-induces overlying ectoderm to form neural plate -> neural tube
11
Q
- AR
- global reduction or absence of pigment in skin, hair and eyes
- eye conditions: nystagmus, strabismus, light sensitivity
A
albinism
12
Q
- autoimmune disorder
- loss of melanocytes
- possible environmental effects
- may be AD inheritance with variable expression and incomplete penetrance
A
vitligo
13
Q
which wave is at fault in anencephaly?
A
wave 2
14
Q
spina bifida (myelo/meningocele) is a failure at the junction of which two waves?
A
waves 1 and 5
represents the junction of 1º and 2º neurulation
15
Q
cranial neuropore closes at day:
caudal neuropore closes at day:
A
cranial neuropore closes at day 24
(failure to close -> anencephaly)
caudal neuropore closes at day 27
(failure to close -> spina bifida)
16
Q
somites may differentiate into: (4)
A
bone, cartilage, muscle, dermis of skin
all except the epidermis!
17
Q
intermediate mesoderm differentiates into: (2)
A
kidneys and gonads
18
Q
the chordamesoderm differentiates into the:
A
notochord
19
Q
notochord differentiates into the:
A
nucleus pulposus
20
Q
erector spinae muscles develop from the:
A
epimere
21
Q
intramembranous ossification typically occurs where?
A
mostly in cranial vault
everywhere else is usually endochondral
22
Q
- deficiency in type 1 collagen
- multiple variants
- characterized by extreme bone fragility and spontaneous fractures
A
osteogenesis imperfecta
23
Q
- most prevalent form of dwarfism
- mutation in FGF-23
- pathologic changes at epiphyseal plates
- zones of proliferation and hypertrophy are narrow and disorganized (endochondral formation)
A
achondroplasia
24
Q
_____________ -> somites -> ___________ -> vertebrae
A
paraxial mesoderm -> somites -> sclerotomes -> vertebrae
25
the connective tissue (skeletal and vascular) of the limb arises from the:
lateral plate mesoderm
26
initiation of limb development begins with activation of the:
lateral plate mesoderm
27
outgrowth of the limb bud is stimulated by the:
apical ectodermal ridge (AER)
28
- produced at apical ectodermal ridge
| - stimulates mitosis of underlying mesoderm, providing for lengthening of limbs
FGF gene
29
- produced at base of limbs in zone of polarizing activity
- involved in patterning along anterior-posterior axis
- involved in CNS development; mutation can cause holoprosencephaly
sonic hedgehog gene
30
four drugs that cause reduction defects (part or all of limb is missing):
- thalidomide
- dimethadione
- aspirin
- retinoic acid
31
- MC limb abnormality
- webbed fingers or toes
- failure of programmed apoptosis in digital ray
syndactyly
32
A 4‐day‐old boy is brought into the pediatric clinic because of breathing difficulties and poor feeding. He coughs, chokes and spits up milk very soon after beginning to nurse. Physical examination and subsequent radiographs reveal the presence of the most common type of tracheoesophageal fistula. This defect results from:
B. failure of tracheoesophageal septum to fuse
33
development of lungs and laryngeotracheal (respiratory) diverticulum begins in what week?
week 4
34
A 27‐week‐oLd male fetus is delivered prematurely and subsequently dies of respiratory distress syndrome. What pathologic process most likely lead to the infant’s demise?
C. inadequate pulmonary surfactant
35
A 6 day old boy presents with a history of complete loss of breath at times and occasional cyanosis. If the baby is held in an upright position, his breathing improves. Physical examination reveals an usually flat stomach when the baby is lying down, and auscultation demonstrates no breath sounds on the left side of the thorax. What is the most likely diagnosis?
```
A. Unilateral pulmonary agenesis
B. Esophageal hiatal hernia
C. Respiratory distress syndrome
D. Congenital diaphragmatic hernia
E. Congenital neonatal emphysema
```
D. congenital diaphragmatic hernia
36
sympathetic innervation of FOREGUT –
- preganglionic cell bodies:
- splanchnic nerve:
- preaortic ganglion:
- postganglionic axons follow:
sympathetic innervation of FOREGUT –
- preganglionic cell bodies: T5 – T9
- splanchnic nerve: greater splanchnic n.
- preaortic ganglion: celiac
- postganglionic axons follow: celiac a.
37
sympathetic innervation of MIDGUT –
- preganglionic cell bodies:
- splanchnic nerve:
- preaortic ganglion:
- postganglionic axons follow:
sympathetic innervation of MIDGUT –
- preganglionic cell bodies: T9 – T12
- splanchnic nerve: lesser splanchnic n.
- preaortic ganglion: superior mesenteric
- postganglionic axons follow: SMA
38
sympathetic innervation of HINDGUT –
- preganglionic cell bodies:
- splanchnic nerve:
- preaortic ganglion:
- postganglionic axons follow:
sympathetic innervation of HINDGUT –
- preganglionic cell bodies: T12 – L2
- splanchnic nerve: least splanchnic n.
- preaortic ganglion: inferior mesenteric
- postganglionic axons follow: IMA
39
parasympathetic innervation of FOREGUT & MIDGUT –
- preganglionic cell bodies:
- nerve:
- location of ganglion:
parasympathetic innervation of FOREGUT & MIDGUT –
- preganglionic cell bodies: brainstem
- nerve: vagus n. (CN X)
- location of ganglion: organ walls
40
parasympathetic innervation of HINDGUT –
- preganglionic cell bodies:
- nerve:
- location of ganglion:
parasympathetic innervation of HINDGUT –
- preganglionic cell bodies: S2 – S4
- nerve: pelvic splanchnic nerves
- location of ganglion: organ walls
41
A woman comes to your office for a standard prenatal visit. Examination reveals that her uterus is considerably larger than expected for her estimated gestational age. Ultrasound examination reveals that she has polyhydramnios. Which of the following congenital defects would most likely be associated with this abnormality?
```
A. bilateral renal agenesis
B. esophageal atresia
C. pulmonary hypoplasia
D. ureteral obstruction
E. urachal fistula
```
B. esophageal atresia
| polyhydramnios – baby unable to take in amniotic fluid
42
- nonbilious vomiting in newborn
| - "olive-sized mass" in epigastric region
pyloric stenosis
43
- bilious vomiting in newborn
| think. ..
duodenal atresia
| or annular pancreas
44
- midgut loop fails to return to abdominal cavity
| - sealed by peritoneum
omphalocele
45
- extrusion of abdominal contents through abdominal folds
- failure of anterior wall musculature to close during folding
- NOT covered by membrane
gastroschisis
46
A 7 month old baby presents with swollen umbilicus that has failed to heal normally. The umbilicus drains secretions, and occasionally fecal material passes through the umbilicus. What is the most likely diagnosis?
```
A. duodenal atresia
B. esophageal stenosis
C. gastroschisis
D. ileal diverticulum
E. omphalocele
```
D. ileal (Meckels) diverticulum
- "rule of 2's"
- remnant of vitelline duct
- asymptomatic
47
A newborn boy does not pass meconium until 48 hours after his birth. Several weeks later his mother complains that he has not been passing stool regularly. Diagnostic exam reveals increased internal anal sphincter pressure on rectal distension with a balloon. The patient’s disorder may be attributed to:
B. failure of neural crest cells to migrate into the colonic wall (Hirschprungs)
48
failure of Rathke folds to develop, resulting in a:
rectourethral fistula
49
A mother brings her 4‐year‐old daughter to the physician complaining that despite being toilet‐trained, the child seems to regularly wet herself. An intravenous pyelogram shows complete duplication of the ureter on the right side. Although one ureter opens normally into the bladder, the other opens into the vagina. This congenital anomaly is caused by:
B. early complete division of the ureteric bud
50
horseshoe kidney usually found inferior to which vessel?
inferior mesenteric artery (IMA)
51
While examining a newborn baby, a physician notes that urine is draining from the umbilicus. Contrast dye is introduced into the bladder through the urethra, and it is confirmed radiologically that dye is passing to the umbilicus. Which of the following embryonic structures has abnormally been retained in this patient?
A. Allantoic duct (urachus -> median umbilical ligament) – will see urine out of umbilicus
aside: feces through umbilicus, think ileal (Meckels) diverticulum.
52
primitive vertebrate cardiovascular plan present by which week?
week 4
53
truncus arteriosus becomes:
aorta, pulmonary trunk
54
bulbus cordis becomes:
smooth part of R ventricle (conus cordis)
| smooth part of L ventricle (aortic vestibule)
55
primitive ventricle becomes:
trabeculated part of R and L ventricles
56
primitive atrium becomes:
trabeculated part of R and L atria
57
sinus venosus becomes:
smooth part of R atrium (sinus venarum)
coronary sinus *
oblique vein of L atrium
58
- MC positional abnormality
| - folding of heart takes place in opposite direction
dextrocardia
59
- MC congenital heart defect
- membranous 90% of the time
- large defects can result in L -> R shunting, cyanosis and death
- associated with fetal alcohol syndrome, Down syndrome, trisomies 13 and 18
ventricular septal defects
60
A newborn baby is observed to be cyanotic immediately after birth. Diagnostic studies, including ultrasound, reveal that the baby has persistent truncus arteriosus. Which of the following additional defects is this baby most likely to have?
B. Membranous ventricular septal defect
61
tetralogy of fallot:
- overriding aorta
- ventricular septal defect
- pulmonary stenosis
- right ventricular hypertrophy
62
a patent ductus arteriosus connects which two vessels?
aorta pulmonary artery
63
list a few necessary physiologic changes which allow the sperm to penetrate the egg (sperm capacitation): (3)
- removal of some epididymal and seminal glycoproteins
- increase in membrane permeability to Ca2+
- Ca2+ influx maximizes cAMP -> increases sperm motility
64
what are the three main events in fertilization?
1. sperm binding to ZP3
2. acrosome reaction
3. sperm-egg fusion
65
explain the acrosome reaction.
which enzymes are released?
what do the enzymes do?
sperm binds ZP3 receptor and allows for the acrosome reaction or the release of enzymes (neuramidase and acrosin) from the acrosomal space of the sperm to break down the zona pellucida
66
what happens after the first sperm fertilizes the egg?
proteases released from the cortical granules present in the egg remove oligosaccharides from ZP3 and partially cleave ZP2
prevents polyspermy (results in nonviable zygotes)
67
a mutation in lzumo (immunoglobulin superfamily) creates the inability for the sperm to:
fuse to the egg and undergo this acrosome reaction
68
explain both the fast and slow components of the cortical reaction.
fast component: change in resting potential of oocyte plasma membrane prevents further binding of sperm (i.e., "shocks" sperm to get them to let go)
slow component: release of cortical granules containing enzymes (into PVS) that destroy sperm receptors (ZP3 Rs)
69
once the zygote undergoes cleavage into 8 cells, it's called:
morula
70
the blastocyst hatches from it szona pellucida at day...
day 6 or 7
71
implantation of the blastocyst is mediated by:
penetrating trophoblastic cells
72
day 6-7: blastocyst implantation –
| what type of cells invade part of the myometrium (interstitial invasion)?
differentiated syncytiotrophoblastic cells
73
endovascular invasion initiates what?
endovascular invasion initiates the primitive uteroplacental circulation and represents the starting point of the future intervillous space
74
trophoblast infiltration gives rise to:
trophoblast infiltration gives rise to lacunae (pools of maternal blood)
75
once implanted the syncytiotrophoblast begins to secrete:
hCG
(secreted into maternal lacunae)
(the secretion of estrogens and progesterone by the corpus luteum is now under the control of hCG)
76
how does the decidua provide an immune-protective environment for the development of the embryo? (3)
- production of immunosuppressive substances to inhibit the activation of NK cells at the implantation site
- secretion of IL-2 to prevent maternal tissue rejection of the implanting embryo
- syncytiotrophoblasts do not express MHC class II, therefore cannot present Ags to maternal CD4+ T cells
77
at the end of the second week, cytotrophoblastic cells proliferate and extend into the syncytiotrophoblast mass, forming th:
primary villi
78
early in the third week, the extraembryonic mesoderm extends into the primary vili, forming the:
secondary villi
(in cross section, a secondary villus is formed by a core of extraembryonic mesoderm surrounded by a middle cytotrophoblast layer and an outer layer of syncytiotrophoblast)
79
cells of the XE mesoderm differentiate into capillary and blood cells, forming the:
tertiary villi
80
what is the main difference between the secondary villi and the tertiary villi?
the presence of capillaries in tertiary villi
81
which maternal Abs can pass through the placenta?
IgG
82
if the fetus is Rh(+) and the mother is Rh(–), what can happen in subsequent pregnancy?
Abs to D Ag (IgG) cross the placenta and cause hemolysis of fetal RBCs
Rx Rhogam
83
the portion underlying the implantation site and forms the maternal part of the placenta:
decidua basalis
84
TQ
| what are the two components of the placenta?
- decidua basalis
| - chorion frondosum
85
list the components of the placental barrier (4)
syncytiotrophoblast - 1
cytotrophoblast -2
extraembryonic mesenchyme - 3
fetal endothelium - 4
86
placental abruption (hemorrhage into the decidua basalis) leads to:
premature placental separation and bleeding, which impairs oxygenation of the fetus
87
placenta previa:
implantation of the placenta over the cervical os
88
implantation of the placenta through the serosa and into the surrounding tissues, such as the bladder:
placenta percerta
89
- the contractions of the uterine muscles are not strong enough and postpartum bleeding occurs
- predisposing factors include: abnormal labor, substantial enlargement of the uterus, or uterine fibroids (leiomyomas)
uterine atony
90
- sign of placental aging
| - risk factor = smoking
placental calcification
91
malignant gestational trophoblastic disease (GTD) is diagnosed on the basis of elevated tumor markers, primarily:
ß-hCG
92
- 46XX (>90%), paternal origin
- 46XY, paternal origin
- NO fetal tissue*
- extensive hydropic villi (grapelike clusters are diagnostic characteristic)
- extensive trophoblastic hyperplasia with significant atypia
complete mole
93
- triploidy (>90%) or tetraploidy
- PRESENCE of fetal tissue*
- limited and focal hydropic villi
- focal trophoblastic hyperplasia with mild atypia
partial mole
94
- invasion into myometrium of edematous chorionic villi covered with layers of proliferative trophoblastic cells
- ß-hCG moderately elevated
invasive moles
95
- malignancy of trophoblastic tissue (cytotrophoblasts, syncytiotrophoblasts)
- NO chorionic villi*
- presents with abnormally high ß-hCG, shortness of breath, hemoptysis
- hematogenous spread to lungs
- very responsive to chemotherapy
choriocarcinoma
96
1º oocytes are held in:
prophase I (until ovulation)
97
2º oocytes are held in:
metaphase II (until fertilization)
98
postmenopausal labs –
- estrogen:
- GnRH:
- FSH:
- LH:
postmenopausal labs –
- estrogen: decreased
- GnRH: increased
- FSH: marked increase
- LH: increase
99
3 phases of the ovarian cycle:
1. follicular (days 1–14)
2. ovulation
3. luteal (days 15–28)
100
- growth of the dominant follicle
- typically lasts 10-14 days
- duration of this phase is variable due to variable length of menstruation
which phase?
follicular phase
101
during the ovulation phase, the oocyte ruptures out of the:
Graafian follicle
| occurs mid-cycle at day 14
102
- corpus luteum secretes progesterone and estrogen to accommodate potential gestation
- phase is relatively constant, lasting 14 days
which phase?
luteal phase
103
- 1º oocyte surrounded by squamous epithelium
| - BEFORE puberty; inactive follicle
1. primordial follicle
104
- single layer of cuboidal follicular epithelium
| - zona pellucida (barrier between oocte and follicular cells developing in periphery) begins to form
2. early primary (uni-layered) follicle
105
- several layers of cuboidal follicular epithelial cells
| - zona pellucida forms glycoprotein coat around the oocyte
3. late primary (multi-layered) follicle
106
- follicular (aka granulosa) cells continue to proliferate -> stratum granulosum
- ovarian stroma around the follicle differentiates into theca layer (interna and externa)
- antrum begins to form (fluid-filled space, aka liquor folliculi, rich in hyaluronic acid)
4. secondary follicle
107
- specific theca layer
| - squamous cells surrounding follicular cells
theca interna
108
- specific theca layer
| - capsule-like layer continuous with the connective tissue of the ovary
theca externa
109
- antrum occupies much of the space
- oocyte displaced to one side
- developed corona radiata (layer of follicular cells surrounding oocyte)
- developed cumulus oophorus (pedestal of follicular cells anchoring oocyte to the wall
- 1º oocyte nearing completion of meiosis I (not until ovulation)
5. mature (Graafian) follicle
110
the ovulatory phase is triggered by a surge in which hormone?
LH
111
ovulatory phase
| -blood vessels of the theca interna invade the antrum to become the:
corpus hemorrhagicum
112
Mid-cycle pain due to ovulation
Discomfort in lower abdomen due to peritoneal irritation
– Follicle ruptures
Mittelschmerz
113
After ovulation, the residual components of the ruptured follicle forms the:
Corpus Luteum
114
Functions of the Corpus Luteum:
Synthesize and secrete steroid hormones
115
if the corpus luteum is not fertilized, what does it become?
corpus albicans (scar)
116
theca cells are stimulated by what hormone?
| theca cells lack what enzyme?
LH
| theca cells lack aromatase
they have 17a-hydroxylase
117
granulosa cells are stimulated by what hormone?
| granulosa cells lack what enzyme?
FSH
| granulosa (aka follicular) cells lack 17a-hydroxylase
they have aromatase
118
explain the hormonal control of the ovarian cycle.
what happens early in the follicular phase due to low levels of estrogen and progesterone (think feedback)?
what happens later in the follicular phase (think feedback)?
what happens in the luteal phase?
Early in follicular phase, estrogen and progesterone levels are low
119
main 2 hormones of follicular phase:
- FSH
| - estrogen
120
main hormone that stimulates ovulation:
LH
121
main 2 hormones of luteal phase:
- progesterone (mostly from corpus luteum)
| - estrogen
122
3 layers of the uterus:
endometrium – (simple columnar epith) – stratum functionalis and stratum basalis
myometrium – 3 layers of circularly arrange SM
perimetrium – simple squamous epith
123
- component of endometrium
- proliferates and sloughs off during menstruation
- hormone sensitive
- cyclical changes
stratum functionalis
124
- component of endometrium
- regenerates functional layer (stem cells)
- not hormone sensitive
stratum basalis
125
which uterine layer undergoes hypertrophy and hyperplasia during pregnancy?
myometrium
126
blood supply to the uterus is via:
spiral aa.
127
3 phases of menstrual cycle (uterus):
1. proliferative phase (11 days)
2. secretory phase (12 days)
3. menstrual phase (5 days)
128
main hormone secreted by corpus luteum:
| what are some of its functions? (
progesterone ("pro-gestation"):
- stimulation of endometrial glandular secretions and spiral artery development
- maintenance of pregnancy
- decrease myometrial excitability
- inhibition of gonadotropins (LH, FSH)
- relaxes uterine smooth muscle (prevents contractions)
- thick cervical mucus production (inhibits sperm entry into uterus)
129
- functional layer begins to thicken
- spinal arteries are short and deep in the endometrium
- endometrial glands are short, straight, & empty (no glycogen)
which phase of the menstrual cycle is described?
proliferative phase
130
-functional layer very thick
-spiral arteries are long and growing
superficially in the endometrium
-endometrial glands are tortuous and are filled with glycogen-rich secretory products
which phase of the menstrual cycle is described?
secretory phase
131
-initiated by regression of the Corpus Luteum because no fertilization occurred
menstrual phase
132
explain the pathophysiology of dysmenorrhea ("menstrual cramps").
Prostaglandins (PGE2, PGF2a) released from endometrial cells
133
* During pregnancy, the pituitary greatly increases in size due production of FSH, LH, and prolactin BUT...
* Blood supply does not increase with enlarging gland
* Post-partum loss of blood
Sheehan's syndrome
134
* Hypertension (> 140/90) + Proteinuria (> 300mg/24 hr)
* +/- Edema
* After the 20th week of gestation up to 6 weeks postpartum
* Severe ->
Preecclampsia
135
C.R. is a 19-year old nulligravida who present for treatment of chronic pelvic pain. She reached menarche at age 13 and had the onset of severe dysmenorrhea at age 15. She was started on cyclical combined oral contraceptives by her pediatrician as a treatment for her dysmenorrhea. However, the OCPs alleviated little pain and her dysmenorrhea worsened. She now experiences pelvic pain throughout the month and rates her pain as 4 to 6 on a scale out of 10 and 10 out of 10 during menses. She also complains of pain with defecation around the time of menses. Additionally, she became sexually active 6 months ago and experiences severe discomfort with intercourse. C.R. has no history of STI’s. She has no urinary urgency, dysuria, nocturia, diarrhea, or constipation. Her physical examination is normal except for mild uterine and adnexal tenderness.
Endometriosis
• Defined as having non-neoplastic endometrial glands and/or stroma outside of the endometrial cavity
– Ovary = most common site
– Pelvis
– Peritoneum
• Classic Associations
– “Chocolate Cysts” (aka Endometrioma)–blood-filled lesion in the ovary
– “Gun powder” nodules
• Symptoms typically based on site affected
– Uterine ligaments
136
A 21 year old obese female (BMI 32) presents to her gynecologist for evaluation of irregular menses since menarche. She states she has 1 period every 6 months. She also complained of having acne on her face and back as well as excessive facial hair, which requires her to shave every other day, and hair beginning to grow on her abdomen. She denied any changes in her voice and or increase in muscle size. She also denied any headaches, blurred vision, or discharge from her nipples. Signs of hypo-and-hyperthyroidism are negative. Lab studies revealed elevated LH, testosterone, and DHEA-S with a decreased FSH. TSH, prolactin, and IGF-1 were all within normal limits.
Ultrasound revealed multiple cysts in her ovaries bilaterally
Polycystic Ovarian Syndrome
(Stein-Leventhal Syndrome)
• Multiple ovarian follicular cysts due to hormonal imbalance
• Classic presentation
– Obese young woman with oligomenorrhea, infertility, and hirsutism
• Pathophysiology – Increased LH and Low FSH
– Starts with high LH
– LH stimulates theca cells
137
TQ
| Anomalies in structure, function or position of an organ or body region caused by an intrinsic factor
malformation
138
TQ
| Anomalies in structure, function or position of an organ or body region caused by an extrinsic factor
deformations
139
TQ
| Agenesis vs aplasia? (dysplasias)
-Agenesis – absence of a structure resulting from the ABSENCE of its precursor
140
Defects due to a disruption of an originally normal developmental process

disruptions
141
What are the five primary categories of congenital malformations and their relative frequencies?
1) Genetic (18%)
2) Environmental (7%)
3) Multifactorial (25%)
4) Twinning
5) Unknown (40-50%)
142
Not every organism responds to a teratogen in the same way. Why? (4)
1) Concentration and method of teratogen delivery.
2) Timing of exposure
3) Genetic susceptibility
4) Synergy b/n teratogen & other compounds (OTC meds, illicits, eg)
143
MC infectious agents that lead to congenital abnormality? (6)
- Rubella
- Cytomegalovirus (HHV-5)
- Herpes/Varicella
- HIV
- Toxoplasmosis (nonviral)
- Syphilis (nonviral)
144
Infectious Dx?
- Cataracts (glaucoma, blindness)*
- Cardiac defects (PDA)*
- Microcephaly*
- Deafness
Congenital Rubella Syndrome
145
Infectious Dx?
- Microcephaly
- Microphthalmia
- Babies grow slowly (undersized)
Cytomegalovirus (CMV)
146
Infectious Dx?
- retinal dysplasia*
- microcephaly
- microphthalmia
- blisters
Herpes
147
Infectious Dx?
- mental retardation
- limb hypoplasia
- muscle atrophy
Varicella Zoster
148
Infectious Dx?
| -Low teratogenic potential
HIV
149
TQ
| -Protozoa
Toxoplasmosis (nonviral)
150
-Syphilis, caused by a spirochete
Treponema palldum (nonviral)
151
MC physical agents that lead to congenital abnormality? (6)
- Ionizing radiation
- Maternal fever
- Maternal hyperthermia
152
Physical agent?
- microcephaly
- mental & growth retardation
- leukemia
- Severity of defect depends on duration & timing of exposure
Ionizing Radiation: Acute high dose (>250 rads)
Diagnostic: rarely
```
note:
Birth defects (and increased rates of cancer in adults) have been blamed on U.S. depleted uranium from armor-piercing shells used in Iraq, Bosnia, Kosovo and Serbia
```
153
Physical agent?
-CNS problems
-craniofacial anomalies include:
microcephaly, sm midface, malformed ears, cleft lip.
High maternal fevers
Mom gets sick esp early in preg-->very hi fevers, esp teratogenic during 1st trimester. OR sauna/hot tub
154
MC chemical agents that lead to congenital abnormality? (3)
1) Pharm drugs
2) Recreational drugs
3) Heavy metals (lead/mercury)
155
Category A: These drugs are the safest. Well-designed studies in humans show no risks to the fetus.
Category _: Evidence shows a risk to the human fetus, but drug benefits may outweigh risks in certain situations.

Category _: Risk to the fetus has been proven to outweigh any possible benefit.
D
| X
156
What can the anti-anxiety agent diazepam cause?
Cleft lip and palate
157
Drug?
| Can cause stained teeth & enamel hypoplasia
Tetracycline
158
Drug?
- can cause sensorineural deafness
- "ototoxic“ or toxic to the cochlear and vestibular system
Streptomycin
159
```
TQ
Drug?
-can cross the placental barrier
-hypoplastic (BEAKED/FLAT)*
-hydrocephaly or microcephaly
-upper airway obstructions.
-serious CNS and eye problems, with serious mental retardation and seizures
-calcifications
-Many die in infancy

```
Fetal warfarin syndrome
Warfarin is an anticoagulant (blood thinner) that is prescribed to persons who have had heart-valve replacement surgery or other heart problems.
Use heparin instead!
160
```
TQ
Which class of drugs inhibit folate metabolism-->neural tube defects?
+course hair and mental def
+hypoplastic digits
+smooth filtrum**
```
Anticonvulsants (Valproic acid, trimethadone, diphenylhydantoin)
Fetal hydantoin (dilantin) syndrome
161
Antihypertensives:
___ ______: Intrauterine growth retardation, fetal death.
___-______: *Fetal bradycardia & hypoglycemia, growth retardation.
_____ ______: Growth retardation & a decrease in the fetal levels of oxygen, sodium, and potassium and in the number of platelets.
ACE inhibitors
Beta-blockers
Thiazide diuretics
162
- used in chemotherapy, psoriasis, rheumatoid arthritis, initiate therapeutic abortion.
- neural tube defects
- microcephaly, craniosynostosis, micrognathia, and dysplastic, low-set ears.
- Most patients die in utero or in the first year of life. However, longer-surviving children tend to exhibit normal intelligence.
Antineoplastic agents:
- Aminopterin
- Methotrexate
- Busulfan
(dihydrofolate reductase inhibitors...no folate)
163
What has been shown to cause cleft lip/palate in lab rats, suggesting that large doses from dietary supplements should be avoided during pregnancy?
Where else is this chemical found?

vitamin A
Accutane, Rogaine (Minoxidil).
Retinoic acid is present as a morphogen in normally developing embryos. However, high doses may cause serious birth defects if taken any time after the 15th day of pregnancy.
164
Mom taking supplement has baby with...Dx?
- TRIANGLE FACE*
- Facial asymmetry
- Dysmorphic external ears
- Hypertelorism (wide b/t eyes)
- Facial paralysis
- Hydrocephaly
- Microcephaly
- Mental retard
- heart problems
Retinoic acid embryopathy
165
TQ
- Very effective anti-emetic for preg women.
- LIMB DEFECTS
- Disrupts signal for LIMB genesis, particularly in "Progress zone"-->progress zone stops-->limb stops extending-- > thinks it's distal-->hand/foot develops.
- *Also used as dietary agent and for Leprosy
Thalidomide "Thalimb- no-mide"
166
- Intrauterine growth restriction
- BEHAVIORAL PROBS (cant pay attn, learning diff)
- psychomotor dysfxn
- abd pain, HA, vomiting, confusion
Lead
crosses placental barrier
167
T/F
| LSD, PCP, Weed, Cocaine are not proven teratogens
TRUE
168
- Sm, addicted baby.
| - Can inc miscarriage, preemies.
Opiates:
Heroin, Methadone, Morphine.
Cross placenta.
169
What drug?
| -Premature birth
METH
170
TQ
- Mental retardation w/ social/behavioral problems
- Broad spectrum of defects, esp facial abnmlities,
- external ear malformations
- FLAT MIDFACE
- short nose
- thin upper lip w/ indistinct philtrum
- low nasal bridge
ETOH
ALCOHOL IS THE MOST COMMON TERATOGEN TO WHICH HUMAN EMBYROS ARE EXPOSED.
3oz daily during first trimester
171
masculinization of the external genitalia in females and may cause hypospadias in male fetuses.
Androgenic hormones
172
T/F
| Cigarette (Tobacco) smoking has not been linked to major birth defects
TRUE
| It does contribute to intrauterine growth retardation and premature delivery.
173
- A synthetic estrogen that was used to prevent spontaneous abortion.
- causes congenital abnormalities of the vagina & uterus (T- shaped) in women who were exposed in utero.
- There is also an increased risk for vaginal adenocarcinoma.
Diethylstilbestrol (DES)
174
-In addition to fertility issues, which group of women have a greater risk of miscarriage.
Anorexic a/o bulimic
175
MOST ELEMENTS OF THE FACE (BONE,CARTILAGE) ARE DERIVED FROM WHICH OF THE FOLLOWING?
A. Cranial intermediate mesoderm
B. Cervical somites
C. Somatic cranial lateral plate mesoderm
D. Neural-crest derived mesenchyme
E. Splanchnic cranial lateral plate mesoderm
D. Neural-crest derived mesenchyme
176
```
THE DEVELOPING FACE IS FORMED BY TISSUE FROM THE FIRST PHARYNGEAL ARCH. THE CRANIAL NERVE ASSOCIATED WITH THIS ARCH IS WHICH OF THE FOLLOWING?
A. Trigeminal
B. Facial
C. Glossopharyngeal
D. Vagus
E. Hypoglossal
```
A. Trigeminal
177
A NEWBORN IS BORN WITH A DEEP FISSURE OF THE LEFT NOSTRIL THAT EXTENDS THROUGH THE UPPER LIP. PHYSICAL EXAMINATION SHOWS NO ANOMALIES OF THE MANDIBLE OR PALATE. WHICH OF THE FOLLOWING DEVELOPMENTAL DEFECTS IS MOST LIKELY RESPONSIBLE FOR THESE FINDINGS?
A. Failure of the left lateral palatine process to fuse with the median palatine process
B. Failure of the left maxillary process to fuse with the left nasomedial process
C. Failure of the primary palate to fuse with the secondary palate
D. Failure of the right and left nasomedial prominences to merge
E. Failure of the right palatine process to fuse with the left palatine process
B. Failure of the left maxillary process to fuse with the left nasomedial process
178
```
THE INTERMAXILLARY SEGMENT FORMS VIA THE FUSION OF WHICH OF THE FOLLOWING?
A. Lateral nasal prominences
B. Mandibular prominences
C. Maxillary prominences
D. Palatine shelves
E. Medial nasal prominences
```
E. Medial nasal prominences
179
```
IN THE DEVELOPING FACE, WHICH EMBRYOLOGICAL PROMINENCE IS ASSOCIATED WITH THE FIRST DIVISION OF THE TRIGEMINAL NERVE (CN V1)?
A. Frontonasal
B. Mandibular
C. Maxillary
D. Orbital
E. Palatal
```
How about V2?
How about V3?
A. Frontonasal (V1)
V2 = maxillary prominence
V3 = mandibular prominence
180
A FAILURE IN FUSION IN WHICH OF THE FOLLOWING PROCESSES RESULTS IN A SECONDARY OR POSTERIOR CLEFT PALATE?
A. Left and right palatal shelves
B. Mandibular prominences
C. Maxillary and mandibular prominences
D. Medial nasal prominences
E. Palatal shelves and intermaxillary process
A. Left and right palatal shelves
181
```
DURING YOUR PEDIATRIC CORE CLERKSHIP, YOU ASSIST IN THE EVALUATION OF A NORMAL‐APPEARING NEWBORN WHO PRESENTS WITH DIFFICULTY IN FEEDING. THE BABY EAGERLY ACCEPTS MILK FROM A DROPPER BUT EXHIBITS DIFFICULTY IN SUCKLING FROM A BOTTLE. WHAT UNDIAGNOSED CONGENITAL ABNORMALITY COULD BE RESPONSIBLE?
A. Abnormal innervation of CN IX
B. Cleft palate
C. DiGeorge syndrome
D. Lateral facial cleft
E. Second arch syndrome
```
B. Cleft palate
| no suction if you do not have roof to cavity
182
```
DURING YOUR OB/GYN ROTATION YOU ASSIST IN THE DELIVERY OF A NEWBORN WITH CRANIOFACIAL ANOMALIES. THE BABY HAS MICROGNATHIA, A CLEFT PALATE AND GLOSSOPTOSIS. WHICH OF THE FOLLOWING IS THE MOST LIKELY DIAGNOSIS?
A. Digeorge Syndrome
B. Hemifacial microsomia
C. Pierre Robin Syndrome
D. Treacher Collins Syndrome
E. Velocardiofacial Syndrome
```
C. Pierre Robin Syndrome
183
```
FAILURE OF THE FRONTONASAL PROCESS TO DEVELOP OR FUSE WITH THE SURROUNDING CRANIOFACIAL PROCESSES RESULTS IN WHICH OF THE FOLLOWING MALFORMATIONS?
A. Bilateral complete cleft palate
B. DiGeorge syndrome
C. Facial cleft malformation
D. Pierre Robin sequence
E. Unilateral complete cleft palate
```
C. Facial cleft malformation
184
IN CASES OF HOLOPROSENCEPHALY, DEFECTS OF FACIAL STRUCTURES ARE TYPICALLY SECONDARY TO DEFECTS OF WHICH OF THE FOLLOWING?
a. Eyes (micropthalamia)
b. Forebrain
c. Midbrain & cerebellum
d. Hindbrain
e. Oronasalcavity
b. Forebrain
185
```
DURING YOUR PEDIATRIC CLERKSHIP, YOU ASSIST IN THE EVALUATION OF AN INFANT WHO IS BROUGHT IN BECAUSE HIS PARENTS THINK THATHISHEAD“DOESN’TLOOKNORMAL.” THECHILDHASALONG WEDGE‐SHAPED SKULL AND YOU ARE ASKED FOR YOUR OPINION REGARDING A DIAGNOSIS. CLOSER PHYSICAL EXAMINATION REVEALS THAT THE SUTURES BETWEEN THE PARIETAL BONES ARE PREMATURELY FUSED. WHAT WOULD BE YOUR INITIAL DIAGNOSIS?
A. Brachycephaly
B. Hydrocephaly
C. Plagiocephaly
D. Scaphocephaly
E. Trigonocephaly
```
D. Scaphocephaly
186
```
AN INFANT IS BROUGHT INTO THE CLINIC FOR A WELL‐BABY CHECK. THE CHILD HAS A VERY SHORT AND WIDE SKULL. CLOSER PHYSICAL EXAMINATION REVEALS THAT THE CORONAL SUTURES ARE PREMATURELY FUSED. WHAT IS THE MOST LIKELY DIAGNOSIS?
A. Brachycephaly
B. Hydrocephaly
C. Plagiocephaly
D. Scaphocephaly
E. Trigonocephaly
```
A. Brachycephaly
187
Premature fusion of lambdoid suture:
| Premature fusion of meitopic suture:
Lambdoid suture = Plagiocephaly
Meitopic suture = Trigonocephaly
188
In the normally developing embryo, aortic arches are apparent by the end of the fourth week. Which of the following arteries is derived from the third pair of aortic arches?
A. Carotid
189
Meckel's cartilage is a prominent structure in the early formation of which of the following?
A. Hard palate
B. Mandible
190
1st-arch neural crest fails to migrate ->
| Mandibular hypoplasia, facial abnormalities
Treacher-Collins syndrome
191
```
The second pharyngeal arch contributes to the formation of which of the following?
A. Auditory tube and incus
B. Auditory tube and stapes
C. Cochlea and ear lobe
D. Otic vesicle and stapes
E. Stapes and ear lobe
```
B. Auditory tube and stapes
192
In the developing embryo, pharyngeal arches are formed. The second (branchial) arch gives rise to the stapedius, orbicularis oris, and posterior belly of the digastric muscles. Which of the following cranial nerves is also derived from this arch?
A. III
C. VII (Facial N)
193
```
Damage to the glosspharyngeal nerve would result in paralysis of which of the following?
A. Hyoglossus
B. Palatopharyngeus
C. Styloglossus
D. Stylopharyngeus
E. Tensor Veli Palatini
```
C. Stylopharyngeus
194
Explain Stern's Rule for muscles of the head and neck and their innervation.
Stern's Rule:
"Tensor" – CN V (Trigeminal)
"Palat" – CN X (Vagus)
"Glossus" – CN XII (Hypoglossal)
Hierarchical... e.g., Palatoglossus – CN X (Vagus)
195
```
A female infant is born with malformations of the face related to abnormal development of the pharyngeal arches. These include abnormal patterns of muscles of facial expression and mastication. Which of the following functional components is associated with those cells that innervate skeletal muscles originating from pharyngeal arches?
A. GSA
B. GSE
C. GVE
D. SVA
E. SVE
```
E. SVE
Innervation of muscles derived from the branchial arches is referred to as "branchial motor" – SVE
196
A boy presents with mandibular hypoplasia, hearing loss, downward slanting eyes, micrognathia, underdeveloped zygoma, drooping part of the lateral lower eyelids and
malformed of ears. These physical findings are related to a defect in development in which of the following?
A. First arch
B. Second arch
C. Third arch
D. Fourth arch
E. Sixth arch
A. First arch
Treacher-Collins syndrome, aka Mandibulo-facial dysostosis:
- TCOF1 gene – Treachle protein
- Neural crest cells fail to migrate to 1st and 2nd pharyngeal arches
- AD, Chr. 5
(External ear abnormalities – think 1st arch)
197
Micrognathia
Glossoptosis
Airway obstruction
Dx?
Pierre Robin sequence
| 1st arch abnormality
198
```
A newborn is evaluated for minor craniofacial abnormalities. On assessment, it is discovered that there is no external auditory canal. Lack of an external auditory canal is related to abnormal development of which of the following?
A. First pharyngeal cleft
B. First pharyngeal pouch
C. Second pharyngeal cleft
D. Second pharyngeal pouch
E. Third pharyngeal cleft
```
A. First pharyngeal cleft
199
T/F: Tympanic membrane contains ectoderm, a little bit of mesoderm, AND endoderm on the inside.
TRUE
200
Ant asp of SCM with fluid coming out
C. Pharyngeal (branchial) cyst
201
Ext auditory meatus
B. First pharyngeal cleft
202
Question that talks about something off of midline of the neck (SCM). What are you thinking?
```
Pharyngeal cyst
Pharyngeal fistula (purulent outward drainage)
```
203
The two superior and two inferior parathyroid glands are found adjacent to the posterior aspect of the thyroid gland. From which of the following are these parathyroid glands derived in embryologic development?
D. Pharyngeal pouches
204
```
A child is evaluated for a very small mandible and ears that are represented by small protuberances bilaterally. The baby has had numerous episodes of pneumonia and is small for its age. What is the most likely diagnosis?
A. DiGeorge syndrome
B. First arch syndrome
C. Hemifacial microsomia
D. Pierre Robin syndrome
E. Treacher Collins syndrome
```
A. DiGeorge syndrome
- Presents looking like 1st arch problem, BUT then you see recurrent infections (due to T cell deficiency.
- May also see hypocalcemia
- 22q11 deletion syndrome
Aberrant development of 3rd and 4th pouches -> T cell deficiency (thymic aplasia) and hypocalcemia (failure of parathyroid development). Also associated with cardiac defects (conotruncal anomalies).
205
The anterior endoderm of the fourth pouch develops an ultimobranchial body that migrates to the thyroid gland and becomes part of the gland. Cells from the ultimobranchial body differentiate into __________ ____ (C cells) that produce _________.
The anterior endoderm of the fourth pouch develops an ultimobranchial body that migrates to the thyroid gland and becomes part of the gland. Cells from the ultimobranchial body differentiate into PARAFOLLICULAR CELLS (C cells) that produce CALCITONIN.
206
The fact that the posterior one-third of the tongue is innervated by the glossopharyngeal nerve (for both somatic and sensory innervation) reflects the development of its mucosa along side which of the following?
C. Third pharyngeal arch
207
```
A 15-year-old male has a noticeable swelling in his neck that recently began increasing in size. The swelling is located in the midline of the neck, just inferior to the hyoid bone. The mass moves upward with protrusion of the tongue. What is the most likely embryological origin of this swelling?
A. Cervical sinus
B. Second pharyngeal pouch
C. Third pharyngeal groove
D. Ectopic lingual tonsil
E. Thyroglossal duct cyst
```
E. Thyroglossal duct cyst
208
MEMORANG REVIEW ($$$ slide 46):
Aortic arch derivatives
Branchial cleft derivatives
Branchial (pharyngeal) arch derivatives
Branchial pouch derivatives
REVIEW ON MEMORANG!
