Embryology Flashcards
1
Q
Fertilization
A
- Ovulation mid-menstrual cycle
- 12-24 hours
- Begins in fallopian tube
- Migrates to uterus
- Implants in uterus by day 6 – then termed “blastocyst”
2
Q
Week 3
A
-
Gastrulation: differentiation of
- Endoderm (lining of GI and respiratory tracts)
- Ectoderm (nervous system)
- Mesoderm (44 somites become sclerotomes and myotomes become skeletal muscles and axial skeleton)
- Cardiovascular system develops
- Nervous system development
- Notochord to ectoderm to neural plate to neural groove and neural folds to neural tube
- Neural crest cells migrate to sides of neural tube (sensory ganglia, Schwann cells, meninges)
- Neural tube closure begins at 21 days and is completed by 28th day
- Failure of neuropore to close = neural tube defect [ie. anencephaly (cranial end) or spina bifida (caudal end)]
3
Q
Embryo Development
A
- Week 4
- Heart begins to beat
- 5 vesicle brain develops
- Week 7
- 4 cavity heart
- Week 8
- Separate digits
- Week 10
- Human profile to face
4
Q
Periods of Development in Utero
A
-
Embryonic Period
- 0-60 days
- “fundamental importance”
-
Fetal Period
- 60+ days
- Period of maturation
- “fetus”
***The greatest amount of bone development is during the last trimester
5
Q
Malformations- Genetic
A
- Genetic abnormality from egg or sperm, or chromosomal abnormality in gamete
- Autosomal (chromosomes other than sex chromosomes) e.g. Down syndrome
- Sex chromosomes (X or Y chromosome) e.g. Turner syndrome
- 50% of genetic abnormalities result in spontaneous abortion ie miscarriage
6
Q
Malformations- Environmental
A
- Environmental: teratogens e.g. drugs, virus
- Certain stages of developmental process more prone to teratogens than others e.g. the most critical period for brain developmental 3-16 weeks gestation
7
Q
Amniocentesis
A
-
Amniocentesis (13-14 weeks gestation):
- sample amniotic fluid via needle aspiration through abdomen and uterus in conjunction with ultrasonography for detection of birth defects
8
Q
Chorionic Villus Sampling
A
- 9-12 weeks gestation
- Sample of chorionic villus taken via needle either via abdomen and uterus with ultrasonography or transcervically for detection of birth defects
9
Q
Anomaly
A
Anomaly: structural abnormality; significant in that it may be indicative of additional anomalies or symptomatic of a syndrome
10
Q
Primigravida
A
Primigravida: first pregnancy
11
Q
Primipara
A
Primipara: first birth
12
Q
Normal full term development:
A
- 38-42 weeks
- Before 38 weeks is premature
- OB will not let pregnancy go beyond 42 weeks because of risk to infant
13
Q
Gestational age (GA):
A
Gestational age (GA): number of weeks gestation when child born
14
Q
Post-conceptual age (PCA):
A
Post-conceptual age (PCA): if child premature and not yet term age, this term is used instead of GA
15
Q
Chronological age (CA):
A
Chronological age (CA): amount of time since birth
