Embryology (defects) Flashcards
what is spina bifida
Fusion does not occur properly and the neural tube does not close properly; primary
problem is the failure to complete neurulation (posterior neuropore).
what determines where damage is in spina bifida
Lack of fusion
determines where the damage is.
what is the functionality of the spina bifida point
There is normal function
what is the least sever from of spina bifida
spina bifida occulta is the least severe, spinal
vertebrae have not formed properly.
what is a classic physical sign of spina bifida
Classical forms shows a bulge of tissue that may be CSF
or involve tissue.
how can spina bifida be prevented
Mothers should take folic acid! - decreases risk
can surgery help spina bifida
Surgery can help anatomical but not functonal problems.
what is Anencephaly
compromised development of the head and skull due to
lack of closure of the anterior neuropore
what is cleft palate
Shows failure to correctly form the face
where are defects commonly found in cleft palate
defects are mostly in the mouth and nasal area.
what is a key feature of cleft lip
almost always asymmetrical
what is a feature of cleft palate
almost always central.
what is treatment of cleft palate
Able to surgically
fix the problem, results are good because babies cells are proliferating so quickly so the
healing process is very quick and occurs without scarring.
what was thalidomide initially marketed to treat
Used to treat morning sickness (1958-1961)
what was the problem with thalidomide
resulted in limited development of upper
limbs and relatively normal development of lower limbs.
Additionally, deformed eyes and
hearts, deformed alimentary and urinary tracts, blindness and deafness.
why does thalidomide cause problems
Interferes with blood vessel development, affecting nutritional supply which results in cell
death; resulting limbs are unable to be used.
why are limbs particularly vulnerable to thalidomide
Morning sickness at 8 weeks gestation
overlaps with limb development,
what is thalidomide currently used for
used in leprosy and cancer treatment; should not be given to women of
reproductive age.
name 2 features of the teratology of fallot
septal defect between the ventricles (which tends to allow deoxygenated blood into the left ventricle
stenosis of the pulmonary artery (decreasing blood flow to the lungs).
what is another cardiac abnormality
Transposition of the great arteries… aorta connected to RV, pulmonary artery connected to
LV- generating two separate blood flows.
why does transposition of the great arteries cause problems after birth
Before birth, FO and DA allow mixing of blood
flows sufficiently to sustain fetal growth and development.
Closure of these connections
after delivery separated to blood flows, so the infant become cyanotic.
what is another term for cyanotic infant
blue baby syndrome
what immediate treatment could be given for artery transposition
administer prostaglandins to keep the ductus arteriosus open, and perhaps opening of a link between the atria
what definitive treatment is ultimatley required for artery transposition
switching of the two arteries, to restore the normal blood flows.
what are teratogens
factors which dysregulate patterning, causing defects in development.
when do teratogens exert their effect
first trimester of pregnancy
Many different factors can act as teratogens such as….
illegal drugs, medications and
radiation,
