CH 9 CONGENITAL DISORDERS Flashcards
What is the process by which tissues and organs assume their form?
Morphogenesis
What is the study of fetal malformations?
Teratology
Why is the first trimester highly sensitive?
Organogenesis occurs
What will happen if the fetus is exposed to a teratogenic factor in the first two weeks of pregnancy?
It will likely fail to implant
What will happen if the fetus is exposed to teratogenic factors in the last 2 trimesters?
It will likely interfere with the rate of cell division
What is the failure of normal fusion of apposed structures?
Dysraphic anomalies
What is the persistence of fetal structures that would normally regress?
Involution failures
What is incomplete cleavage of structure e.g. syndactyly?
Division failure
What is incomplete formation of lumen of a structure e.g. esophagus?
Atresia
What is failure of organ to move into the usual position during development?
Dystopia
What are 3 classes of teratogens?
- Radiation
- Chemicals
- Infectious agents
What is the difference between teratogens and fetotoxins?
Teratogens cause morphogenetic factors, fetotoxins cause toxic effects e.g. low birth weight, premature birth, death
What are 2 examples of drugs that are teratogenic?
Diethylstibestrol (DES) and thalidomide
What is the term used in clinical settings to describe the collection of similar manifestations in newborns with infection?
TORCH syndrome
What is a dysraphic effect where the neural tube fails to close?
Anencephaly
What are 2 other neural tube defects that are more compatible with survival?
Spina bifida and meningocele
What can prevent neural tube defects?
Folic acid
What are 3 facial characteristics of fetal alcohol syndrome?
- Small eye openings
- Smooth philtrum
- Thin upper lip
What are 3 body characteristics of fetal alcohol syndrome?
- Small head
- Short height
- Low weight
What are 3 behavioral characteristics of fetal alcohol syndrome?
- Poor coordination
- Hyperactive
- Learning difficulties
What is severely impaired limb development seen in thalidomide babies?
Phocomelia
What is thalidomide used for now?
Anti-neoplastic drugs
What are 3 categories of congenital disorders based on the cause?
Single gene disorders
Polygenic disorders
Multifactorial disorders
What 2 terms describe whether the gene mutation is found on one or both chromosomes?
Heterozygous or homozygous