Malformations In Development Flashcards
What can congenital defects be caused by?
environmental factors
Chromosomal factors
Multifactorial
Unknown
What is a malformation?
A structural defect of part or the whole organ caused by an abnormal process intrinsic to its development
What is a disruption?
A defect i. An organ or body part caused by a process that interferes with an originally normal developmental process
What is a deformation?
A structural abnormality caused by mechanical forces
What is a sequence?
A pattern of multiple malformations stemming from a disturbance of developmental processes or a mechanical factor
What is a syndrome?
A group of malformations of different structures due to a single primary cause but acting through multiple developmental. Pathways
What is an association?
A group of anomalies seen in more than one individuals that cannot yet be attributed to a definitive source
What is a teratogen?
An agent which can disturb development of an embryo or foetus
In the forst two weeks following conception what ar the results of teratogen exposure?
It will either have no effect is only one or two cells are killed or there will be spontaneous abortion if more cells are killed
In the embryonic period, what effect will teratogens have?
Severe Malformation of the embryo
In the foetal period, what effect will teratogens have?
Functional disturbance of the foetus
What factors can be teratogens?
Environmental factor ssuch as drugs, chemicals, industrial pollutants, hormones
Infectious agents
Mechanical factors
Which system is sensitive to teratogens for the longest period of time?
CNS
How did thalidomide cause amelia and meromelia?
Blood vessels in the limbs leaked and caused damage to the cells in the early progress zone of the early limb bud so that proximal structures didnt develop
What defects can be caused by high doses of streptomycin in pregnancy?
Inner ear defects
What syndrome can result from the use of epilepsy drugs in pregnancy?
Foetal hydatoin syndrome
What abnormalities can methotrexate cause in a foetus?
Craniofacial abnormalities and developmental delays
What facial features result from foetal hydatoin syndrome?
Prominent eyes
Increased space between eyes
Microcephaly
What facial features result from methotrexate exposure of the foetus during pregnancy?
Prominent eyes with increased spacing
Low set ears
Sparse eyebrows
The intake of how much alcohol per day is associated with foetal alcohol syndrome?
80ml of spirits
What effects does foetal alcohol syndrome have on the foetus?
Facial deformities Low birth weight Small head circumference Developmental delay Poor coordination and motor skills Poor socialisation Memory problems Behavioural problems
What effect does cocaine use have on a foetus?
Premature labour
Spontaneous abortion
Malformation of heart and genitourinary system
Behavioural issues
At what stage in pregnancy is rubella virus infection particularly dangerous?
First three months
What defects can rubella virus infection cause for a foetus?
Cataracts
Disruption of organ of corti resulting in deafness
In the first three months of pregnancy cytomegalovirus causes spontaneous abortion. What are its results after this time?
Cerebral palsy
Deafness
What effect can herpes simplex virus have on the foetus?
Mental retardation
Microcephaly, hydrocephalus and mental retardation can result from toxoplasmosis infections during pregnancy. How can the mother become infected?
Handling cat litter, raw meat or unwashed fruit and veg
