MEDRADSC 2X03 Lecture Notes - Lecture 13: Fetal Alcohol Spectrum Disorder, Inner Cell Mass, Late Effect
23 Apr 2019
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Document Summary
Radiation as a teratogen: teratogen, known teratogens: Thalidomide - anti nausea medication used in 90s. General effects on embryo and fetus: lethality. Spontaneous abortion: congenital abnormalities present at birth, stochastic effect - chance, germ cells affected - mutation may be passed down through generations. Not demonstrated during u/s scans -> only seen first at birth: long term (late) effects not visible at birth but develop later in life. Leukemia vs. sold tumour latent period length: leukemia has the shortest (5-7 years) vs. solid tumours (10-15+ years) Cell deaths leading to malformation during organogenesis. Second trimester: growth disturbances w/o malformations. Can happen at any point during development - usually third trimester: all are considered to be due to cell killing, not cell mutation. 3 stages of fetal development: pre-implantation - first 2 weeks, organogenesis - weeks 3-8, fetal stage - weeks 9 - term, radiation on embryo and fetus. 11-14 differentiation of embryoblast into 3 primary germ layers.
