Embryo Flashcards
1
Q
Preimplantation diagnosis of genetic disorders
A
- 3-5 days post in vitro fertilization
- 1-2 blastomeres (cells) tested
- PCR & FISH (fluorescence in situ hybridization)
- Sex determined for sex linked traits
2
Q
Abnormal embryos and spontaneous abortions
A
- Natural screening of embryos occurs
- Abortion can occur b/c of chromosomal abn.
- Higher abortion rate in fetus w/ neural tube defects, cleft lip, cleft palate
3
Q
Ectopic pregnancies
A
- Implantation outside uterus
- Most in ampulla & isthmus
- Ampulla = implant can expel to peritoneal-abdominal preg
- Isthmus = ruptures early, profuse bleeding from anastomoses of ovarian and uterine vessels
4
Q
Tubal pregnancies
A
- Often related to delay or inability to transport zygote to uterus
- Causes for delay : mucosal adhesions, PID (pelvic inflam. disease)
- Symptoms of preg + potential abdominal pain
5
Q
Intramural tubal pregnancy
A
- Implant in uterine part of tube
- Zygotes may develop to fetus before rupture
6
Q
Abdominal pregnancy
A
- Fetus may be delivered alive
- Placenta attached to abdominal organs / risk of maternal death
- Simultaneous intra, extrauterine pregnancies can but rarely occur
7
Q
Placenta previa
A
- Fetus implantation near internal os = placenta cover os
- May = bleeding b/c premature separation of placenta
- Cesarian section required for total block
8
Q
Spontaneous abortion of embryos and fetuses
A
- Miscarriage occurs within the first 12 wks of pregnancy 10-20% of time
- Most during first 3 wks
- 30 - 50% of all zygotes never develop into blastocysts
- Chromosomal abnormalities common cause
9
Q
Inhibition of implantation
A
- Morning after pill = high doses of estrogens/progestins = no implantation
- Intrauturine device inserted into uterus > local inflam rxn > implantation prevented
10
Q
Pregnancy tests
A
- HCG is used to detect early preg
- Bleeding at time of menstruation does not rule out preg
11
Q
HCG
A
- Human chorionic gonadotrophin
- Produced by syncytiotrophoblast
- Released by cleaving zygote
12
Q
Sacrococcygeal teratomas
A
- From remnants of primitive streak
- Tumors = tissues from 3 germ layers
- Most common tumor in newborns
- Most common in females
- Most benign, surg removed
13
Q
Remnants of notochord tissue
A
- Chordoma: arise from remnants of notochordal tissue
- 1/3 from base of cranium to nasopharynx
- Slow growing
- If malignant infiltrate bone, difficult to remove
14
Q
Allantoic cysts
A
- Remnants of extra embryonic portion of allantois
- Usually between fetal umbilical vessels near ant. wall
- Asymptomatic until childhood/adolescence = become inflamed
15
Q
Omphalocele
A
- Congenital herniation of viscera into proximal umbilical cord
- Associated with allantoic cysts
16
Q
Birth defects result from abnormal neurulation
A
- Timing of neurulation > defects - commonly neural tube defects
- Meroencephaly/anencephaly: partial/complete absence of brain (most common NTD affecting CNS)
- Disturbance in neuroectoderm, failure of neural folds to fuse
17
Q
Hyatidiform moles
A
- Abnormal growth of trophoblast
- Cystic swellings from degen. villi following embryo death
- Produces high HGC
- Resemble a grape bunch
18
Q
Choriocarcinoma
A
- Metastasize to various sites: lungs, vagina, liver, bones, intestine, brain
- Produced fro hyatidiform moles (3-5% of moles progress)
19
Q
Complete hydatidiform moles
A
- Monospermic: Follow fert. of empty oocyte (inactive/absent pronucleus)
- Dispermic: fert. empty oocyte 2 sperm
- Most complete hydatidiform moles are monospermic
- Nuclear DNA is paternal
20
Q
Partial hydatidiform mole
A
- Normal oocyte fert. w/ 2 sperm (dispermy)
21
Q
Ultrasonography of chorionic sac
A
- Size of sac > determine gestation age
- Detectible when median sac 2-3mm
22
Q
Embryonic age
A
- begins at fert.
23
Q
Last normal menstrual period (LNMP)
A
- 2 wks before embryonic age starts
- 1st day of LNMP marks gestational age
24
Q
Oligomenorrhea
A
- Scanty menstruation
- Lead to LMNP unreliability
25
Placental transport mechanisms (in add. to s. diff, f. diff, act trans. pinocytosis)
- Fetal RBCs > maternal circ. through microscopic breaks, can occur maternal > fetal
- Cross under own power (maternal leukocytes, Treponema palladium = syphilis)
- Infect placent, create lesions (Toxoplasma gondii)
26
Hemolytic disease of newborn
- Fetal erythroblastosis
- Rh(-)mom, Rh(+)dad > Rh(+) fetus
- anti-Rh ab > hemolysis of fetal RBCs
- Anemia, jaundice
- Rh ig to mother to prevent
27
Gestational trophoblastic disease
- Gestational choriocarcinoma
- Abnorm proliferation of trophoblast cells
- Cells penetrate deciduas basalis, may metastasize
28
Gestational choriocarcinomas treatment
- Respond strongly to chemo
| - Cures usually achieved
29
Placenta accrete
- Abnorm adherence of chorionic villi to myometrium
- 3rd trimester bleeding common
- Placenta stick to uterine wall > hemorrhage
30
Placenta percreta
- Chorionic villi penetrate myometrium to perimetrium
- 3rd trimester bleeding common
- Placenta sticks to uterine wall > hemorrhage
31
Placenta previa
- Placenta implants close to uterine os
32
Performed to assess fetal acid-base status
- Percutaneous umbilical cord blood sampling
33
Umbilical artery doppler velocimetry
- Investigate preg complications (intrauterine growth retard, fetal distress from hypoxia, anoxia)
- IUGR associated w/ increased umbilical artery resistance
34
Absence of umbilical artery
- Agenesis/degradation of vessel in early dev.
| - Associated 15-20% w/ cardiovascular defect
35
Oligohydramnios
- Disorder of amniotic fluid volume: it's low
- Preterm rupture of amniochorionic membrane, placental insufficiency, renal agenesis
- Ass. complications: pulm hypoplasia, facial defects, limb defects compression of umbilical cord
36
Polyhydraminos
- Disorder of amniotic fluid volume: it's high
- Fetus not swallowing amniotic fluid (esophageal atresia)
- Ass. complications: meroanencephaly, anencephaly)
37
Rupture of amniochorionic membrane
- Lead to premature labor
| - Oligohydraminos
38
Amniotic band syndrome/amniotic band disruption complex
- Rupture of amnion
- Constriction by encircling amniotic bands
- Ass. malformations: digital constriction, major scalp, craniofacial and visceral defects
39
Allantoic cysts
- Cystic mass in umbilical cord
- Maybe remains of extra embryonic part of allantois
- Usually resolve but can be associated w/ an omphalocele
40
Erythrocyte mosaicism
- Anastomose b/t blood vessels of fused placentas of DZ twins
41
Twin-transfusion syndrome
- Shunt of blood b/t twins: t1 > anastomose > v circ. t2
- Donor t: small anemic
- Recipient t: large, polycythemic
- 30% of monochorionic-monoamniotic twins
- Laser ablation of shunt possible
42
Establishing zygosity of twins
- Molecular diagnosis
| - Monochorionic-monoamniotic twin placenta: 50% mort rate due to tangled umbilical cords
43
Causes of discordant MZ twins
- vascular abnorm.
- somatic mut
- chromosome aberrations
- X chromosome inactivation (female twins)
44
Early death of a twin
- Early death + resorption of 1 twin = common
| - Errors prenatal cytogenetic diagnosis
45
Conjoined MZ twins
- Embryonic disc (or other discs) don't divide > conjoined ts
- Possible cnxns: cutaneous, liver
- Surgery can be impossible
46
Superfecundation
- Fertilization of 2 or + oocytes @ 2x
47
Superfetation
- 2 fetuses in uterus from fert @ 2x
48
Ichthyosis
- Group of disorders = excessive keratinization
| - Dryness, fishskin-like scaling
49
Harlequin fetus
- Inherited
| - Skin is thick, ridged, crack
50
Collodian baby
- Thick taught membrane cover @ birth
- Cracks w/ 1st respiratory effort
- Falls off in sheets
51
Lamellar ichthyosis
- Like collodian baby, but scaling remains
| - Sweat glands/hair dev impeded
52
Congenital ectodermal displasia
- Hereditary
- Involving ectodermal tissues
- Teeth absent
- Hair nails and skin affected
53
Ectrodactyly-ectodermal dysplasia-clefting syndrome (EEDCS)
- 3 cond: Ectodermal dysplasia, ectrodactyly, facial clefts
54
Ectodermal dysplasia
- Hypopigmentation skin, hair
- Little hair/eyebrows
- No eyelashes
- Nail dystrophy
- Hypdodontia, microdontia
- Cleft lip/palate
55
Angiomas of skin
- Vascular anomaly > transitory/surplus blood or lymph vessels persist
- Mainly arterial, venous, cavernous angiomas (dilation of blood vessels)
56
Port-wine stain
- Hemangioma
- Large, red
- Anterior or lateral on face/neck
- Sharply demarcated when near median plane (doesn't cross)
- A port-wine stain in area of trigeminal nerve = angioma of meninges > seizures at birth (Sturge-Weber syndrome)
57
Common angioma
- Pinkish, red blotch
| - Can cross median plane
58
Multiple hemangiomas
- May be associated with internal hemangiomas
| - Internal maybe affect airways, liver, hematologic disturb.
59
General albinism
- Autosomal recessive
| - Skin, hair, retina lack pigment
60
Cause of albinism
- Melanocytes don't produce melanin due to lack of tyrosinase or other pigment enzyme
61
Localized albinism
- Autosomal dominant
| - Lack of melanin in patches of skin or hair
62
Gynecomastia
- Excess dev of male mammary tissue
- Stim of glandular tissue by maternal sex hormones
- Effects disappear
63
Athelia
- Absence of nipples
64
Amastia
- Absence of breasts
65
Cause of athelia and amastia
- Failure of dev or disappearance of mammary crests
| - Failure of mammary bud to form
66
Aplasia of breast
- Breasts of post pubertal women differ in size (normal)
| - Large difference = rudimentary dev thoracic wall muscle
67
Polymastia
- Extra breast
| - Dev from extra mammary buds along mammary crest
68
Polythelia
- Extra nipple
| - Dev from extra mammary buds along mammary crest
69
Supernumerary nipples
- Common in males
- Mistaken for moles
- Dev from extra mammary buds along mammary crest
70
Inverted nipple
- Nipple fails to elevate above skin
| - Remain in newborn location
71
Alopecia
- Absence/loss of scalp hair
72
Congenital alopecia
- Hair loss > failure of hair follicle dev / poor quality hair production
73
Hypertrichosis
- Excessive hairiness
- Supernumerary hair follicles
- Lanugo hairs
- Localized or diffuse
74
Pili torti
- Hairs twisted/bend
- Familial disorder
- Associated w/ other ectodermal defects
75
Aplastic anonychia
- Congenital absence of nails
- Nail fields don't form / no nail plates (permanent)
- Can associate w/ defects in hair / teeth
- 1 or more nails, hands or feet
76
Natal teeth
- Teeth erupted @ birth
- 1/2000
- Breastfeeding is a bitch!
77
Enamel hypopasia
- Defective enamel formation
| - pits and/or fissures in enamel
78
Numerical abnormalities
- 1 =,
79
Dentigerous cyst
- Cyst in mandible, maxilla, or maxillary sinus w/ unerupted tooth
- Cystic degeneration of enamel reticulum of enamel organ
80
Amelogenesis imperfecta
- 14 clinical entities = dev abnorm in enamel formation
- Inherited ectodermal birth defect
- Enamel hypoplastic, hypocalcified, or hypomature
81
Detinogenessi imperfecta
- Teeth = brown or gray
- Odontoblasts don't differentiate and poorly calcify dentin
- Both deciduous and permanent teeth are involved
82
Tetracycline (context = teeth)
- Extensively incorporated into teeth (enamel + dentin)
- Binds to brown/yellow hydroxyapatite crystals
- Susceptible: 14 wks to 10 month for deciduous and up to 8 pny for permanent
83
Rickets
- Vit D deficiency > intestinal calcium absorption impaired
- Formation of ossification of epiphyseal cartilage plates disrupted
- disorientation of cells at metaphysic
- Limbs are shortened and deformed, sever bowing
84
Achondorplasia
- Common cause of dwarfism
- Disturbance of endochondral oss at epiphysial cartilage plates > limbs bowed and short
- Trunk=short, head=enlarged, bulging forehead, scooped out nose
85
Thanatophoric dysplasia
- Lethal skeletal dysplasia
- Infants die within minutes from resp failure
- MUTATED FGF3
86
Hyperpituitarism
- Gigantism: excessive hight/body
- Acromegaly: enlargement soft tissues, visceral organs, bones of face, hands, feet
- Epiphysial and diaphysial center in long bones fuse = no elongation of bones
87
Cretinism
- Growth retard, mental def, skel abnorm.
- Def of fetal thyroid hormone
- Iodine def in H2O, thyroid agenensis = causes
88
Poland syndrome
- Absence of pec major and minor
- Ipsilateral breast hypoplasia
- Absence of 2 - 4 ribs
89
Arthrogryposis multiplex congenital
- Failure of normal muscle development > immobility of joints
- 1/3000 births
- Includes > 300 heterogeneous disorders
90
Congenital absence of diaphragm
- Incomplete expansion of lungs (pulmonary atelectasis)
| - Pneumonitis (lung tissue inflam)
91
Congenital tortcollis
- Injury to sternocleidomastoid muscle
- Fibrosis + shortening SCM > fixed rotation, tilting of head
- AKA WRYNECK
- Tearing SCM @ birth > bleeding > hematoma > mass of fibrous tissue > ipsilateral shortening
92
Amelia
- Suppression of limb bud dev > Missing limb/limbs
93
Meromelia
- Disturbance of limb dev > Missing PART limb/limbs
94
Cleft hand
- Failure of dev of digital rays > Missing central digits
95
Congenital absence of radius
- Failure of mesenchymal primordial of radius not form (genetic factors) > hand deviates laterally and ulna bows
96
Brachydactyly
- Short digits
| - Reduction in phalanx length
97
Polydactyly
- Supernumerary digits
| - inherited
98
Cutaneous syndactyly
- Failure of webs b/t fingers to degen > webbed digits
99
Osseus syndactyly
- Notches b/t digital rays fail to develop
| - Digits don't separate
100
Hemimelia
- Lack of pre/post-axial partition of the limb muscles
101
Ectrodactyly
- Missing middle digits of hand
102
Causes of limb anomalies
- Genetic factor
- Environmental factors (thalidomide)
- Vascular disruption & ischemia
- Multifactorial inheritance (genetic + environment)
