teratogenesis Flashcards
Define and describe the stages of human development.
Pre-embryonic Period: fertilization through implantation
Embryonic Period: implantation through gestational week 8
Fetal Period: week 8 through birth (parturition)
Describe the three layers that result from differentiation of the inner cell mass.
endo, ecto, mes, maternal endometrium and the embryonic trophoblast will combine to form the placenta.
is hep b part of torch?
may be, if mom has active hep b during birth so is part of torch syndrome
what can torch cause?
fever difficulties feeding small areas of bleeding under the skin enlargement of the liver and spleen (hepatosplenomegaly) Jaundice hearing impairment abnormalities of the eyes each infectious agent may also result in additional abnormalities that may be variable, depending upon a number of factors (e.g., stage of fetal development).
Define teratogen and give examples.
define: Any Agent That Can Produce a Congenital Anomaly or Raise the Incidence of an Anomaly in the Population
mom exposed, kid get problems (or embryo dies)
examples: cocaine, cigarette smoke,
Compare and contrast the various etiologies of congenital abnormalities.
cocaine: Increased risk of related congenital anomalies resulting from vascular disruption Skull defects Cutis aplasia Porencephaly Subependymal and periventricular cysts Ileal atresia Cardiac anomalies Visceral infarcts
Teratogenicity is Governed by the Principles of Teratology, what are they?
The capacity of an agent to produce birth defects depends on:
- Developmental stage at the time of exposure
- Dose and duration of exposure
- Genotype of the embryo
- Mechanism of action is specific and may involve inhibition of specific biochemical or molecular process (cell death, decreased cell proliferation, or other cellular phenomena)
- Manifestations of abnormal development are death, malformation, growth retardation, and functional disorders
- Access of adverse influences to developing tissues depends on the nature of the agent.
Stages of Development and Effects of Teratogens
Pre-embryonic Period: fertilization through implantation: Kill embryo (spontaneous abortion, which goes unnoticed) –or- the disruptive effects are compensated for by the early embryo.
Embryonic Period: implantation through gestational week 8
Most sensitive period for inducing major birth defects.
Fetal Period: week 8 through birth (parturition)
Teratogen damage is unlikely to produce malformations but can cause death, growth retardation, disruptions or functional deficits.
Teratogenicity is Governed by the Principles of Teratology, what are they?
The capacity of an agent to produce birth defects depends on:
- Developmental stage at the time of exposure
- Dose and duration of exposure
- Genotype of the embryo
- Mechanism of action is specific and may involve inhibition of specific biochemical or molecular process (cell death, decreased cell proliferation, or other cellular phenomena)
- Manifestations of abnormal development are death, malformation, growth retardation, and functional disorders
- Access of adverse influences to developing tissues depends on the nature of the agent.
Embryonic Period: Period time and effects of teratogens
implantation through gestational week 8
Most sensitive period for inducing major birth defects.
Fetal Period: Period time and effects of teratogens
week 8 through birth (parturition)
Teratogen damage is unlikely to produce malformations but can cause death, growth retardation, disruptions or functional deficits.
Cocaine is a _____
Teratogen
Cocaine adverse effects ___
Local vasoconstrictor-adverse effects from vasoconstrictive and hypertensive properties.
High risk of still birth because of vascular disruption (highest risk after the first trimester of pregnancy)
Cocaine Maternal complications:
Maternal complications: MI, arrhythmias, aortic rupture, stroke, seizure, bowel ischemia and sudden death.
Cocaine Exposed embryo is ___
Exposed embryo at higher risk for placental abruption
