4.1- Peds 1 Flashcards
Starts with egg being fertilized-after fertilization the cell divides until a sphere of cells is formed. During implememtation into the uterus, that inner layer of cells beomes the embryonic disc.
Preembrionic stage
Conception to 2 weeks
Preembrionic stage
14 days - 8 weeks
embryonic stage
Embryonic stage:
- Edges of the ______fold towards each other forming the ________ _________
- The folds of the _______ __________ grow toward eachother finally touching around day 21 to make the ________ __________.
- Neural tube closure can be affected by ________/_________, lack of ______ ______etc. before a woman knows shes pregnant.
- disc, neural groove
- neural groove, nerual tube
- alcohol/drugs, folic acid
The neural tube closes first in the cervical region and from the top to bottom like a zipper leaving open ends called?
neuropores
This part of the neuropore closes by day 27
superior neuropore
This neuropore closes about 3 days later, any later will cause abnormalities
inferior neuropore
The folds of the neural groove grow toward each other finally touching around day 21 to make what structure?
Neural tube
What forms the neural groove?
Edges of the embryonic disc
This occurs when the cranial end of the neural tube does not close. Brain stem forms but not the Cerebral or Cerebellar hemispheres. Skull does not form over incomplete brain leaving it exposed-fatal
Anencephaly
Partial failure to close cranial end of the tube causing malformation of teh cerebellum and brain stem. the structure wedge in the foramen magnum causing problems with the circulation of CSF.
Arnold-Chiari malformation
Increased pressure causes enlarged ventricles and increased pressure on the brain stem
hydrocephalus
Not as severe, symptoms often do not start until early adulthood. Causes severe headache, vomiting and lethargy
Type 1-arnold-chiari malformation
Obvious at birth due to enlarged cranium (result of enlarged ventricles) and the fontanel bulges.
Type 2-Arnold-Chiari malformation
Surgically a shunt is run from ventricle to abdomen to relieve pressure. Must watch for signs of shunt blockage.
Type 2-Arnold-Chiari malformation
Signs for shunt blockage:
young child:
Older child:
younger child: bulge of fontanels, thin skin/sparse hair over skull
older child: lethargy, vomiting, confusion, dizziness
Regardless of the type of Arnold-Chiari malformation, we must avoid what?
prolonged head down position
What is spina bifida?
occurs when inferior neural tube does not close
Posterior arch does not close
Bifida vertebrae
What are the 2 types of spina bifida?
- Spina bifida occulta
2. spina bifida cystica
Bony defect, but neural tissue does not protrude-no neural signs-sc works normally. May have tuft of hair over
Spina bifida occulta
Generally lower lumbar, but can affect T-spine, no rx required
spina bifida occulta
Visible cyst protruding from the bony defect that may be covered by skin or meninges
spina bifida cystica
What are the 2 types of spina bifida cystica?
- Meningocele
2. Myelomeningocele